Anypoint Studio Error: The project is missing Munit lIbrary to run tests

Anypoint Studio 7.9 has a bug. Even if we following the article: https://help.mulesoft.com/s/article/The-project-is-missing-MUnit-libraries-to-run-tests-Mule-4, it still would not fix the proble. The only solution at the moment is to add the followiing dependency:

		
			org.mule.weave
			assertions
			1.0.2
			test
		

Access Multiple Github Accounts From One Computer

Step 1: Step 1: Generate SSH and Add it to ssh-agent

Note: if you have two github accounts, you need to generate two SSH Key

Step 2: Configure ~/.ssh/config

Note: In order to access the different account, you must use the hostname specified inside the ~/.ssh/config file. Here is my example:

$ cat .ssh/config
Host *
ServerAliveInterval 240

# garyliu1119 account
Host github1119.com
  HostName github.com
  AddKeysToAgent yes
  IdentityFile ~/.ssh/id_ed25519
  IdentitiesOnly yes

# garyliu19 account
Host github19.com
  HostName github.com
  AddKeysToAgent yes
  IdentityFile ~/.ssh/id_rsa
  IdentitiesOnly yes

When I clone the github repo, I use the following command:

git clone -b develop git@github19.com:garyliu19/FN-External-API.git

Note: the domain name is: github19.com, instead of github.com

Dataweave 2.0: Convert Calendar Date To Julian Date

A Julian date is commonly used in main frame. It's format is YYDDD. DDD is the date since begining of the year. In DetaWeave 2.0 the code should be as the following:

	julianNow: now() as String {format: "YYD"},
	julianAt: "07-10-2020" as Date {format: "dd-MM-yyyy"} as String {format: "YYD"}

Mulesoft Send Email With CSV Attachment

Introduction

This blog explain the tricks to convert csv data to plain text for the purpuse of send csv as attachment. The Mulesoft document can be found at here

  
  
      
          
      
      
          Hello this is an important message"]]>
      
      
        #[{
          'csv-attachment' : payload
        }]
      
  

Code Details

As shown in the follow snapshot, we need to perform two transformations:

• from csv to base64 binary
• from base64 binary to plain text>

The challenge is that we cannot direct convert to "application/csv" to "text/plain".

The details are shown below:

Step 1: Initial code JSON to CSV

%dw 2.0
output application/csv separator=","
---
[
	{
		name: "Gary Liu",
		ssn: "1234"
	},
	{
		name: "John Smith",
		ssN: "4567"
	}
]

Step 2: CSV to Base64 Binary

%dw 2.0
import * from dw::core::Binaries
output text/plain
---
toBase64(write (payload, 'application/csv'))

Step 3: Base64 Binary to CSV Plain Text

%dw 2.0
import fromBase64 from dw::core::Binaries
output text/plain
---
fromBase64(payload)

Take Aways

The line of thinking is that Mule runtime engine internally keeps that data as array of records. This java object cannot direct convert to plain text. The code is really mimic the way we store the data to file and then read the data from file to plain text.

Mule Develop Tricks: Get The Phone Number

The Requirement

The phone number from customer web site is free string. It can take the following forms:

1.  +1 (219) 555-8888
2.  +1 219-555-8888
3.  (219) 555 8888
4.  219 555 8888
5.  219 555-8888
6.  219-555-8888
7.  -1-219-555-8888

There could be other form. 

We need to use dataweave 2.0 to extract 10 digits of the phone number to: 2195558888.

Solution

%dw 2.0

output application/json

---

{

mobile: (payload.mobilePhone replace /([^0-9.]+)/ with(""))[-10 to -1]

}

Take Aways

1. dataweave built in function replace / / with ()
2. substring [-10 to -1] take last 10 digits

Prototyping Mule OAuth2 Client Application

Introduction

This article explains how to prototype Mule OAuth 2.0 client application with grant type of "Client Credentials", which is most popular grant type for Mule integration. Most modern APIs enforce OAuth2.0 security policies. OAuth2.0 has the following Grant Types (The detailed explanation can be found here):

• Authorization Code
• PKCE
• Client Credentials
• Device Code
• Refresh Token
• Legacy: Implicit Flow
• Legacy: Password Grant

This post will cover the following topics:

• Using postman to retrieve access token
• Prototyping retrieve access token using cURL
• Mule flow to retrieve access token
• Sample flow using the access token with caching scope

OAuth 2.0 With Client Credential Grant Type

In order to access the OAuth2.0 enabled APIs, we first have to retrieve the access token from the Identity Providers. Then we can access the API by passing the access token. The parameters for Client Credential can be the following:

• grant_type (required)
• scope (optional)
• client_id (required)
• client_secret (required)

In most cases, cilent_id and client_secret are encrypted as Basic Authentication. The encryption can be done using base64 or openssl as the following:

echo -n "${CLIENT_ID}:${CLIENT_SECRET}" | base64

echo -n "${CLIENT_ID}:${CLIENT_SECRET}" | openssl enc -base64

Note: the "-n" option of echo is for not printing the trailing newline character. This is very important.

Using Postman to Retrieve Access Token

The postman is the best tool to do prototyping for the OAuth 2 client. The following snapshot shows the setup of the Postman:
for body:

for Headers:

for Authorization:

cURL Solution

Once we have the postman, the solution of cUrl is very straight forward.

$ cat oauth2-client.sh

#!/bin/bash
#
CLIENT_ID=MY-CLIENT-ID-GOES-HERE-WITHOUT-QUOTE
CLIENT_SECRET=YOUR-CLIENT-SECRET-GOES-HERE-WITHOUT-QUOTE

OAUTH_HEADER=$(echo -n "${CLIENT_ID}:${CLIENT_SECRET}" | base64)

curl -d "grant_type=client_credentials&scope=https://graph.microsoft.com/.default" \
     -H "Content-Type: application/x-www-form-urlencoded" \
     -H "Authorization: Basic ${OAUTH_HEADER}" \
     -XPOST https://login.microsoftonline.com/keurig.onmicrosoft.com/oauth2/v2.0/token

Mule Application Solution - Retrieve access_token

The mule application flow for retrieving access token is the following:

The Data-Weave transformation code is the following:

%dw 2.0
output application/x-www-form-urlencoded
---
{
 grant_type: "client_credentials",
 scope: "https://graph.microsoft.com/.default"
}

The request configuration is as the following:

The HTTPS connector configuration referred in the request is the following:

The xml configuration is the following:

As you can see, we pass the client_id and client_secret as the username and password of the basic authentication. This is just base64 encoded string. Here is an example of the response from the retrieval of access token.

{
    "token_type": "Bearer",
    "expires_in": 3599,
    "ext_expires_in": 3599,
    "access_token": "eyJ0eXAi......"
}

Mule Application Solution - Use access_token

The following diagram shows the usage of the access_token. The access_token is passed to the server as header.

As you can see, we need to use cache scope. This allow us to avoid calling the server if the token is not expired. In this case, the token will expire in one hour. Thus our object store TTL should be less then 60 minutes.

Anypoint Runtime Fabric : Part 1 - Pre-Installation Network Checking

Introduction

In the next few weeks, I will write more details about Mule runtime fabric installation, configuration, and troubleshooting. This article is about to verify the network connectivity before install Anypoint Runtime Fabric (RTF). In order to install Anypoint RTF, the network firewall must open. The details about the port and host whitelisting can be find here: https://docs.mulesoft.com/runtime-fabric/1.4/install-port-reqs.

Tools for Network Connectivity Checking

The following tools should be installed and configure on the Linux system:

• nslookup
• curl
• nc
• openssl
• chrony

nslookup must configured properly. To verify nslookup, you can use the following command:

nslookup anypoint.mulesoft.com

The above command should print out something like:

Name: anypoint-prod-936665732.us-east-1.elb.amazonaws.com
Address: 52.87.103.123
Name: anypoint-prod-936665732.us-east-1.elb.amazonaws.com
Address: 3.217.25.79
...

This means it is working. If you find a problem, most likely the file /etc/resolv.conf has the incorrect content. It should look like the following:

$ cat /etc/resolv.conf
# Generated by NetworkManager
search gmcr.com
nameserver 10.64.2.13
nameserver 10.124.240.104

The next tool is the well-known cURL. run the following command:

$ curl -sk https://anypoint.mulesoft.com:443

You should see something like the following:

301 Moved Permanently
nginx

This is good. If it hung, then we have problem. I have covered the usage of nc and openssl in my previous post

NTP - Network Time Protocol

In order for Anypoint RTF to work, we must make sure NTP is working in the system. Linux use chrony to perform NTP. Run the following command:

chronyc tracking

If the NTP is working correctly, it should print out the something like the following:

Reference ID    : A3EDDA13 (toddadev.your.org)
Stratum         : 2
Ref time (UTC)  : Mon Feb 03 00:18:55 2020
System time     : 0.000235624 seconds slow of NTP time
Last offset     : -0.000094732 seconds
RMS offset      : 0.000081353 seconds
Frequency       : 16.987 ppm slow
Residual freq   : -0.003 ppm
Skew            : 0.062 ppm
Root delay      : 0.025243049 seconds
Root dispersion : 0.000095447 seconds
Update interval : 514.2 seconds
Leap status     : Normal

Note the Leas status must be "Normal", otherwise, Anypoint RTF will be not working. The real for the Leap status is not normal is the network firewal is not open to the RedHat's time server. In this case, we need to use company's internal time server. To do this, modify the file: /etc/chrony.conf

# Use public servers from the pool.ntp.org project.
# Please consider joining the pool (http://www.pool.ntp.org/join.html).
#server 0.rhel.pool.ntp.org iburst
#server 1.rhel.pool.ntp.org iburst
#server 2.rhel.pool.ntp.org iburst
#server 3.rhel.pool.ntp.org iburst
server server 10.70.0.200
...

The line: server server 10.70.0.200 is company's private time server. Make sure comment out all the RedHat's entries. After the modification of the file of /etc/chrony.conf, make sure run the following command:

sudo systemctl restart chronyd
sudo systemctl enable chronyd

You also may verify the sources of the Ntp by the following command:

chronyc sources

This will restart the chrony daemon.

Network Connectivity Test Scripts

Mulesoft provided a scripts totest the network connectivity at here If you have gone through the test in the previous sections, this script should run with the following results.

Once the above procedures are all done, we are read to perform the installation for Anypoint Runtime Fabric. I will cover that in the following articles.

Anypoint Runtime Fabric - SSL Handshaking Troubleshooting

Introduction

Mulesoft's Anypoint Runtime Fabric is gaining momentum in the hybrid deployment model. Since version 1.4.1, the installation, configuration, and management have improved significantly. However, as it involves TLS/SSL, many things can go wrong. This article will provide some technical insights on how to diagnose those issues. In many cases, it may not be the configuration issues. Sometimes, the issues could be related to client code or network configuration. In later section, I have provided java code to test HTTPS REST API. First let's review the architecture of Anypoint Runtime Fabric.

As shown from the above diagram, the TLS/SSL is applied to all the controllers. Let's say the IP addresses are:
10.64.6.65
10.64.6.66
10.64.6.67
On all of the above controllers, the port 443 should be open. And we should be able to connect to all these controllers by using networking tools like nc, openssl, etc.

Verify Controller's TLS/SSL

First, from the client point of view, we need to make sure the port 443 is open and reachable. To do so, we can execute the following command:

$ nc -zv 10.64.6.65 443
Connection to 10.64.6.65 port 443 [tcp/https] succeeded!

As you can see, we can connect the port 443 successfully. nc is a very light and powerful tool for quickly scan the port of the server. Secondly, we can use openssl to verify the TLS/SSL:

$ openssl s_client -connect 10.64.6.65:443

openssl is a heavy weight tool. It can do a lot things, such as, connection verification, ssl certification generation and conversion, etc. The above command will print out information about the server's TLS/SSL certificates, ssh handshaking, cipher, etc. Here are an example:

$ openssl s_client -connect 10.64.6.65:443
CONNECTED(00000003)
depth=2 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert High Assurance EV Root CA
verify return:1
depth=1 C = US, O = DigiCert Inc, OU = www.digicert.com, CN = DigiCert SHA2 High Assurance Server CA
verify return:1
depth=0 C = US, ST = Texas, L = Plano, O = "Keurig Dr. Pepper, Inc.", CN = *.gmcr.com
verify return:1
---
Certificate chain
 0 s:/C=US/ST=Texas/L=Plano/O=Keurig Dr. Pepper, Inc./CN=*.gmcr.com
   i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
 1 s:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
   i:/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert High Assurance EV Root CA
---
Server certificate
-----BEGIN CERTIFICATE-----
...
-----END CERTIFICATE-----
subject=/C=US/ST=Texas/L=Plano/O=Keurig Dr. Pepper, Inc./CN=*.gmcr.com
issuer=/C=US/O=DigiCert Inc/OU=www.digicert.com/CN=DigiCert SHA2 High Assurance Server CA
---
No client certificate CA names sent
Server Temp Key: ECDH, X25519, 253 bits
---
SSL handshake has read 4087 bytes and written 289 bytes
---
New, TLSv1/SSLv3, Cipher is ECDHE-RSA-AES128-GCM-SHA256
Server public key is 4096 bit
Secure Renegotiation IS supported
Compression: NONE
Expansion: NONE
No ALPN negotiated
SSL-Session:
    Protocol  : TLSv1.2
    Cipher    : ECDHE-RSA-AES128-GCM-SHA256
    Session-ID: 820EF7CA565E40E495662B0D1AAAB24E2AE431B660A86DF7659D2DEFB7B986B1
    Session-ID-ctx:
    Master-Key: 98F3D990B13A2847041E6275682C74F3D371A15C8D0358434957D6B87B865DA9E839AB95950FE6F24E9D5CDD0DE59F93
    TLS session ticket lifetime hint: 7200 (seconds)
    TLS session ticket:
...
    Start Time: 1580667077
    Timeout   : 7200 (sec)
    Verify return code: 0 (ok)
---
closed

The most important information client should notice are the following:

• CN = *.gmcr.com -- This dictate how client should invoke the service
• SHA2 High Assurance Server CA -- SHA2 is Secure Hashing Algorithm 2.
• Protocol : TLSv1.2 -- We are using TLSv1.2, now Anypoint RTF also support TLSv1.3
• Cipher : ECDHE-RSA-AES128-GCM-SHA256
• Verify return code: 0 (ok) -- This is very important.

The last line tells us the TLS certificate is valid and can be verified. If the self-signed certificate is applied, the last line will be something like:

Verify return code: 18 (self signed certificate)

Verify Server's Cipher Suites

It is not very uncommon that server and client could not find the common supported ciphers. To handle this, we need to scan server's cipher suite. I use two tools: nmap and cipherscan. There are many free software available, but I find they are very easy to use and very powerful. Wireshark is another very popular tool. If all of the simple tools are exhausted, we can use Wireshark. Here is example using cipherscan:

$ ./cipherscan 10.64.6.65
Warning: target is not a FQDN. SNI was disabled. Use a FQDN or '-servername '
...............
Target: 10.64.6.65:443

prio  ciphersuite                  protocols  pfs                 curves
1     ECDHE-RSA-AES128-GCM-SHA256  TLSv1.2    ECDH,P-256,256bits  prime256v1,secp384r1,secp521r1
2     ECDHE-RSA-AES256-GCM-SHA384  TLSv1.2    ECDH,P-256,256bits  prime256v1,secp384r1,secp521r1
3     AES256-GCM-SHA384            TLSv1.2    None                None
4     DHE-RSA-AES128-GCM-SHA256    TLSv1.2    DH,2048bits         None
5     AES128-GCM-SHA256            TLSv1.2    None                None

Certificate: trusted, 4096 bits, sha256WithRSAEncryption signature
TLS ticket lifetime hint: 7200
NPN protocols: None
OCSP stapling: not supported
Cipher ordering: server
Curves ordering: server - fallback: no
Server supports secure renegotiation
Server supported compression methods: NONE
TLS Tolerance: yes

Intolerance to:
 SSL 3.254           : absent
 TLS 1.0             : PRESENT
 TLS 1.1             : PRESENT
 TLS 1.2             : absent
 TLS 1.3             : absent
 TLS 1.4             : absent

As you can see, it provide supported cipher and TLS protocols. You can down cipherscan from github: https://github.com/mozilla/cipherscan. nmap is another very powerful and easy to use tool. nmap is a bit slow.

$ nmap -sV --script ssl-enum-ciphers -p 443 10.64.6.65
Starting Nmap 7.80 ( https://nmap.org ) at 2020-02-02 13:11 CST
Nmap scan report for hello-earth.kdrp.com (10.64.6.65)
Host is up (0.086s latency).

PORT    STATE SERVICE   VERSION
443/tcp open  ssl/https
| fingerprint-strings:
|   FourOhFourRequest, GetRequest, HTTPOptions:
|     HTTP/1.1 404 NOT FOUND
|     Content-Length: 0
|     Connection: Close
|   RTSPRequest, SIPOptions:
|     HTTP/1.1 400 BAD REQUEST - bad version
|     Content-Length: 0
|_    Connection: Close
| ssl-enum-ciphers:
|   TLSv1.2:
|     ciphers:
|       TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
|       TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 4096) - A
|       TLS_DHE_RSA_WITH_AES_128_GCM_SHA256 (dh 2048) - A
|       TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 4096) - A
|     compressors:
|       NULL
|     cipher preference: server
|     warnings:
|       Key exchange (dh 2048) of lower strength than certificate key
|       Key exchange (ecdh_x25519) of lower strength than certificate key
|_  least strength: A
1 service unrecognized despite returning data. If you know the service/version, please submit the following fingerprint at https://nmap.org/cgi-bin/submit.cgi?new-service :
SF-Port443-TCP:V=7.80%T=SSL%I=7%D=2/2%Time=5E371EE9%P=x86_64-apple-darwin1
SF:7.7.0%r(GetRequest,40,"HTTP/1\.1\x20404\x20NOT\x20FOUND\r\nContent-Leng
SF:th:\x200\r\nConnection:\x20Close\r\n\r\n")%r(HTTPOptions,40,"HTTP/1\.1\
SF:x20404\x20NOT\x20FOUND\r\nContent-Length:\x200\r\nConnection:\x20Close\
SF:r\n\r\n")%r(FourOhFourRequest,40,"HTTP/1\.1\x20404\x20NOT\x20FOUND\r\nC
SF:ontent-Length:\x200\r\nConnection:\x20Close\r\n\r\n")%r(RTSPRequest,50,
SF:"HTTP/1\.1\x20400\x20BAD\x20REQUEST\x20-\x20bad\x20version\r\nContent-L
SF:ength:\x200\r\nConnection:\x20Close\r\n\r\n")%r(SIPOptions,50,"HTTP/1\.
SF:1\x20400\x20BAD\x20REQUEST\x20-\x20bad\x20version\r\nContent-Length:\x2
SF:00\r\nConnection:\x20Close\r\n\r\n");

Service detection performed. Please report any incorrect results at https://nmap.org/submit/ .
Nmap done: 1 IP address (1 host up) scanned in 46.51 seconds

Verify REST API

From network point view, everything seems working, but client may still have problem to invoke the REST API exposed on the Anypoint RTF. In these cases, we need to check the following. Using postman, if the certificate applied to Anypoint RTF is self-signed, we need to make sure to turn off the ssl verification on the postman.

Still some client are using plain java to invoke REST API. In this case, we can use the following code:

import org.apache.http.Header;
import org.apache.http.HttpEntity;
import org.apache.http.client.methods.CloseableHttpResponse;
import org.apache.http.client.methods.HttpGet;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.apache.http.util.EntityUtils;

public class HttpsHelloWorld {

 public static void main(String[] args) {
  // TODO Auto-generated method stub
  System.out.println("Hello, World");
  HttpGet request = new HttpGet("https://kknxplvmsftct.gmcr.com/earth/hello");
  request.addHeader("Host", "hello-earth-one.gmcr.com");
  CloseableHttpClient httpClient = HttpClients.createDefault();
  
        try {
          CloseableHttpResponse response = httpClient.execute(request);
            // Get HttpResponse Status
            System.out.println(response.getStatusLine().toString());

            HttpEntity entity = response.getEntity();
            Header headers = entity.getContentType();
            System.out.println(headers);

            if (entity != null) {
                // return it as a String
                String result = EntityUtils.toString(entity);
                System.out.println(result);
            }
        } catch (Exception e) {
          e.printStackTrace();
        }
     
 }

}

add the following dependencies to pom.xml

  
    org.apache.httpcomponents
    httpclient
    4.5.10
  
  
  
      org.springframework
      spring-core
      5.2.3.RELEASE
  
  
  
      org.springframework
      spring-web
      5.2.3.RELEASE
  

Or if you prefer to use REST template, you can use the following example:

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URI;
import java.net.URL;

import javax.net.ssl.HttpsURLConnection;

import org.apache.http.conn.ssl.NoopHostnameVerifier;
import org.apache.http.impl.client.CloseableHttpClient;
import org.apache.http.impl.client.HttpClients;
import org.springframework.http.HttpEntity;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.RequestEntity;
import org.springframework.http.ResponseEntity;
import org.springframework.http.client.HttpComponentsClientHttpRequestFactory;
import org.springframework.util.LinkedMultiValueMap;
import org.springframework.util.MultiValueMap;
import org.springframework.web.client.HttpClientErrorException;
import org.springframework.web.client.RestTemplate;

public class HttpsPostMes {

 public static void main(String[] args) {
  try {
   httpsRequestCall3();
   
  } catch(Exception e) {
   e.printStackTrace();
   
  }
     
 }

 public static void httpsRequestCall3() {
  
     CloseableHttpClient httpClient
       = HttpClients.custom()
         .setSSLHostnameVerifier(new NoopHostnameVerifier())
         .build();
     
     HttpComponentsClientHttpRequestFactory requestFactory  = new HttpComponentsClientHttpRequestFactory();
     
     requestFactory.setHttpClient(httpClient);
     
     String urlOverHttps = "https://kknxplvmsftct.gmcr.com/earth/hello";
     
     HttpHeaders headers = new HttpHeaders();
     headers.add("Host", "hello-earth-one.gmcr.com");
      HttpEntity entity = new HttpEntity<>("header", headers);
     
  
     ResponseEntity response = new RestTemplate(requestFactory).exchange(urlOverHttps, HttpMethod.GET, entity, String.class);
     org.springframework.http.HttpStatus code = response.getStatusCode();
     
     System.out.println(code);
     
     System.out.print(response);
  
 } 
  

}

Take Aways

In this article, I have covered the following:

1. Basic Anypoint runtime fabric's controllers
2. Tools to verify servers ports, SSL protocols, and ciphers
   • nc
   • openssl
   • nmap
   • ciphjerscan
3. java code to invoke REST API using https

Mule Integration - Write Elegant Code

Introduction

Recently, I encountered the following piece of Mule Dataweave 2.0 function code.

fun getEmployeePovince(worker) = getStateAbbrevation(worker) match {
     case "AB" -> "AB"
     case "BC" -> "BC"
     case "MB" -> "MB"
     case "NB" -> "NB"
     case "NL" -> "NL"
     case "NS" -> "NS"
     case "NT" -> "NT"
     case "NU" -> "NU"
     case "ON" -> "ON"
     case "PE" -> "PE"
     case "QC" -> "QC"
     case "SK" -> "SK"
     case "YT" -> "YT"
     else -> "ZZ"
    }

The purpose of the above function is to get home province's code of a Canadian employee. The Canadian province code is like, BC for British Columbia, ON for Ontario, etc. The input is an xml object which contains information about the employee. If the worker's province code is not among the list, default to "ZZ".

The above code works and about to go to production. However, this kind of code is really not very cool to say the least. It is just an amateur's code!

Improvement One

First of all, the gist of this kind of problem is to find a match from a given list of Strings. Mule Dataweave 2.0 provides a function, namely find. The documentation can be found here.. The find function works like the following:

['aa', 'bb', 'cc'] find 'xy'  //return [], empty array
['aa', 'bb', 'cc', 'aa'] find 'aa' //return [0, 3]

Now the code using find function should be clear. If the return array from the find is empty (isEmpty(findFunction)), use the input, otherwise, use default, "ZZ".

The following is the datawave code:

%dw 2.0
var CanadianProvinces = ["BC", "MB", "NB", "NL", "NS", "NT", "NU", "NT", "NU", "ON", "PE", "QC", "SK", "YT"]
var pv = payload.state
fun findAKey(aKey) = CanadianProvinces find aKey

output application/json
---
{
 province: if(isEmpty(findAKey(pv))) "ZZ" else pv,
}

The above code is much cleaner. We put the constants of the province code into an array, and use find function. However the above code is still not good for maintenance. Let's see if I want to use the same to logic to US state's code. We have to modify the dataweave code. We can further improve the code. That is to put the constant into property file.

Improvement Two

First, we put the two constants to the yaml property file as the following:

provinces: ["BC", "MB", "NB", "NL", "NS", "NT", "NU", "NT", "NU", "ON", "PE", "QC", "SK", "YT"]
constants:
   default: "ZZ"

%dw 2.0
var provinces = p('provinces')
var pv = payload.state
var dp = p('constants.default')
fun findAKey(aKey) = provinces find aKey

output application/json
---
{
 provice: if(isEmpty(findAKey(pv))) dp else pv,
}

Take Aways

1. Two dataweave 2.0 functions: switch and find
2. Array constants in yaml property file
3. When we encounter some strange code, we should think about the improvement. There is always ways to write elegant code.

Install JSON Plugin In Anypoint Studio

Introduction

JSON Plugin is very useful tool for editing and verifying JSON schemas or json examples data in our API deployment. Unfortunately, it does not come with Anypoint Studio. To me, AnypointStudio should more or less behave like Eclipse which allow us to drag and paste any available plugin. This short article describe the procedure to install the plugin.

Installation of JSON Plugin

First download the plugin zip file from this website to ~/Download. The file name should be like:

rw-r--r--@   1 gl17  staff   112K Sep  3 14:38 jsonedit-repository-0.9.7.zip

Second, in AnypointStudio, Help --> Install New Software --> Add

Note, select Achive and from local file.

After installation, restart the AnypointStudion. Now if you open any json file, the Studio will validate the file.

Manage Mule Runtime Using Linux Services On RHEL 7

Introduction

This article describes the procedures to enable Mule runtime as systemd service for Mule standalone runtime clustering on-premises or in private clouds. Since RHEL 7, the systemd init system is a must. The traditional init.d approach is obsolete. For details about the systemd and Unit files, you may refer to this article.

Assumptions

• Mule standalone runtime is installed at /opt/mule/runtime/current
• Mule runtime can be started and stoped by the command /opt/mule/runtime/current/bin/mule start | stop
• mule user has sudo permission

Create Unit File

First, we need to create a file, mule.service at /etc/systemd/system, with the following contents:

---

# file: /etc/systemd/system/mule.service
# Systemd unit file for mule standalone runtime
[Unit]
Description=Mule Runtime Standalone Runtime
After=syslog.target network.target

[Service]
Type=forking
WorkingDirectory=/opt/mule/runtime/current
Environment=JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.222.b10-0.el7_6.x86_64
Environment=MULE_HOME=/opt/mule/runtime/current
TasksMax=infinity
LimitNOFILE=65335

ExecStart=/opt/mule/runtime/current/bin/mule start
ExecStop=/opt/mule/runtime/current/bin/mule stop

User=mule
Group=mule

RestartSec=10
Restart=always

[Install]
WantedBy=multi-user.target

---

$ cd /etc/systemd/system/
$ sudo chmod 644 mule.service
$ sudo systemctl daemon-reload
$ sudo systemctl enable mule.service

The above command will enable the mule.service. This procedure simply creates a line in the folder of: /etc/systemd/system/system-update.target.wants

systemd-readahead-drop.service -> /usr/lib/systemd/system/systemd-readahead-drop.service

Now, we are ready to start the mule runtime as a service. To do this, we must first stop the running Mule runtime:

$ cd /opt/mule/runtime/current
$ bin/mule stop

Now, run the following command:

$ sudo systemctl start mule.service

It may take sometime before we get the prompt back. After that we can check whether the mule runtime is running or not by the following command:

$ sudo systemctl status mule.service
● mule.service - Mule Runtime Standalone Runtime
   Loaded: loaded (/etc/systemd/system/mule.service; enabled; vendor preset: disabled)
   Active: active (running) since Sat 2019-08-24 15:46:04 CDT; 2h 45min ago
 Main PID: 17555 (wrapper-linux-x)
   CGroup: /system.slice/mule.service
           ├─17555 /opt/mule/runtime/current/lib/boot/exec/wrapper-linux-x86-64 /opt/mule/runtime/current/conf/wrapper.conf wrapper.s...
           └─17569 /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.222.b10-0.el7_6.x86_64/jre/bin/java -Dmule.home=/opt/mule/runtime/current -D...

Aug 24 15:45:41 wp37mulerte01.aci.awscloud systemd[1]: Starting Mule Runtime Standalone Runtime...
Aug 24 15:45:41 wp37mulerte01.aci.awscloud mule[17439]: MULE_HOME is set to /opt/mule/runtime/current
Aug 24 15:45:41 wp37mulerte01.aci.awscloud mule[17439]: MULE_BASE is set to /opt/mule/runtime/current
Aug 24 15:45:42 wp37mulerte01.aci.awscloud mule[17439]: Starting Mule Enterprise Edition...
Aug 24 15:46:04 wp37mulerte01.aci.awscloud mule[17439]: Waiting for Mule Enterprise Edition.......................
Aug 24 15:46:04 wp37mulerte01.aci.awscloud mule[17439]: running: PID:17555
Aug 24 15:46:04 wp37mulerte01.aci.awscloud systemd[1]: Started Mule Runtime Standalone Runtime.

As you can see, the mule runtime is running. If you want to know the deatils about the mule runtime, you can use the following command:

$ sudo systemctl -l status mule.service

The -l option will print out the arguments passed to the JVM. To view the history of stop/start of the Mule runtime, we can use the following command:

$ sudo journalctl -u mule.service
-- Logs begin at Tue 2019-08-06 23:11:10 CDT, end at Sat 2019-08-24 18:39:13 CDT. --
Aug 22 21:40:03 wd35mulerte01.aci.awscloud systemd[1]: Starting Mule Runtime Standalone Runtime...
Aug 22 21:40:03 wd35mulerte01.aci.awscloud mule[31293]: MULE_HOME is set to /opt/mule/runtime/current
Aug 22 21:40:03 wd35mulerte01.aci.awscloud mule[31293]: MULE_BASE is set to /opt/mule/runtime/current
Aug 22 21:40:05 wd35mulerte01.aci.awscloud systemd[1]: mule.service: control process exited, code=exited status=1
Aug 22 21:40:05 wd35mulerte01.aci.awscloud systemd[1]: Failed to start Mule Runtime Standalone Runtime.
Aug 22 21:40:05 wd35mulerte01.aci.awscloud systemd[1]: Unit mule.service entered failed state.
Aug 22 21:40:05 wd35mulerte01.aci.awscloud systemd[1]: mule.service failed.
Aug 22 21:40:14 wd35mulerte01.aci.awscloud systemd[1]: Stopped Mule Runtime Standalone Runtime.
Aug 22 21:52:39 wd35mulerte01.aci.awscloud systemd[1]: Starting Mule Runtime Standalone Runtime...
Aug 22 21:52:39 wd35mulerte01.aci.awscloud mule[32610]: MULE_HOME is set to /opt/mule/runtime/current
Aug 22 21:52:39 wd35mulerte01.aci.awscloud mule[32610]: MULE_BASE is set to /opt/mule/runtime/current
Aug 22 21:52:40 wd35mulerte01.aci.awscloud mule[32610]: Starting Mule Enterprise Edition...
Aug 22 21:53:03 wd35mulerte01.aci.awscloud mule[32610]: Waiting for Mule Enterprise Edition.........................
Aug 22 21:53:04 wd35mulerte01.aci.awscloud mule[32610]: running: PID:32750
Aug 22 21:53:04 wd35mulerte01.aci.awscloud systemd[1]: Started Mule Runtime Standalone Runtime.
Aug 22 21:54:15 wd35mulerte01.aci.awscloud systemd[1]: Stopping Mule Runtime Standalone Runtime...
Aug 22 21:54:15 wd35mulerte01.aci.awscloud mule[633]: MULE_HOME is set to /opt/mule/runtime/current
Aug 22 21:54:15 wd35mulerte01.aci.awscloud mule[633]: MULE_BASE is set to /opt/mule/runtime/current
Aug 22 21:54:15 wd35mulerte01.aci.awscloud mule[633]: Stopping Mule Enterprise Edition...
Aug 22 21:54:18 wd35mulerte01.aci.awscloud systemd[1]: Stopped Mule Runtime Standalone Runtime.
Aug 22 21:55:43 wd35mulerte01.aci.awscloud systemd[1]: Starting Mule Runtime Standalone Runtime...
Aug 22 21:55:44 wd35mulerte01.aci.awscloud mule[912]: MULE_HOME is set to /opt/mule/runtime/current
Aug 22 21:55:44 wd35mulerte01.aci.awscloud mule[912]: MULE_BASE is set to /opt/mule/runtime/current
Aug 22 21:55:45 wd35mulerte01.aci.awscloud mule[912]: Starting Mule Enterprise Edition...
Aug 22 21:56:08 wd35mulerte01.aci.awscloud mule[912]: Waiting for Mule Enterprise Edition.........................
Aug 22 21:56:08 wd35mulerte01.aci.awscloud mule[912]: running: PID:1091
Aug 22 21:56:08 wd35mulerte01.aci.awscloud systemd[1]: Started Mule Runtime Standalone Runtime.

That is it. It is very helpful to study the commands of systemctl and journalctl.

Two-Way SSL In Mule Application - Part 2

Introduction

In my previous article in DZone or here, I omitted the procedure to create a trust store for the application. This is important if the applications are deployed to the CloudHub.

In this article, I will describe the procedures to create the trust store and how to configure the HTTPS request for Mule application

Create A Trust Store FOR MULE HTTPS Request

The procedures to import the server's PEM certificate to a trust store are the following.

First, we will create a trust store using the following command:

keytool -genkey -keyalg RSA -alias cyberark-poc -keystore truststore.ks

Enter anything. They are not important as we will delete it.

Second, delete the content of the trust store just created:

keytool -delete -alias cyberark-poc -keystore truststore.ks

Third, import the server's certificate:

keytool -import -v -trustcacerts -alias cyberark-server -file SERVER-CERT.pem -keystore truststore.ks

Now, copy the truststore.ks to Mule application project /src/main/resources

HTTPS Request Configuration

The following is the complete HTTPS Request configuration:

Note: I put both client.pfx and truststore in the directory of /src/main/resources. You may put them into different directory. In that case, you need to give the full path relative to the Mule Application Project, such as ssh/cert/client.pfx.

The Key Takeaways

The best practice for certificates manipulation is:

1. If the deployment is on-prem, import servers' certificates to cacert. In this way if the server's certificate is expired, we just need to reimport, not code change is required.
2. If the deployment is CloudHub, we have to import the servers' certificate to a truststore as described in this article.
3. Use JKS format for the trust store used in the HTTPS request. It is most popular one.

Two-Way SSL In Mule Application

Introduction

In my previous article, I have explained how Two-Way SSL works with the context of Mule Application. Many people have asked the question about how to setup HTTPS request in Mule application. This article provide the details about the procedures to invoke HTTPS services which require Two-Way SSL or Mutual Authentication. Before we dive into the detail procedures, lets review how Two-Way SLL works between clients and servers.

The gist of Two-Way SSL is to exchange certificates between clients and servers. The details are pretty complicated and they beyond the scope of this article. Basically, here are the high level scheme of the exchange of certificates:

1. Client send a ClientHello message to a server
2. Server replies with ServerHello, Server's certificate, and Request for Client's certificate
3. Client its certificate other information like cipher scheme, server's certificate verification, etc.
4. Server replies with cipher scheme.
5. Start to exchange information

Now, how do we setup Mule Application as client?

Client's Certificate Generation

In general, IT admin will generate client certificates similar as I describe in my blog here Let's assume that is the way for now so that we can describe how to setup Mule HTTPS Request. Before we continue, we need to obtain server's certificate in advance. The certificate can be in many forms like JKS, PKCS12, PEM, etc. Mule HTTPS request support three forms:

• JKS
• PKCS12
• JCEKS

Let's say if we got PEM format from the server. We need to do one of the two things depending on the deployment pattern.

• if it is on-prem deployment, the best way is to import the cert to JVM cacerts
• if it is deployed to MuleSoft CloudHub, we need to convert the PEM to PKCS12.

If it is on-prem deplopment, we can import the the PEM certificate directly into cacerts here is the procedure (Make sure you have sudo permission, and server's cert is named like SERVER_CERT.pem)

cd ${JAVA_HOME}/jre/lib/security
cp SERVER_CERT.pem
sudo keytool -import -alias mule1-cyberark -keystore cacerts -file SERVER_CERT.pem

To be sure that server's cert is in pem format, you can use the following command:

$ openssl x509 -in SERVER_CERT.pem -text

If it is CloudHub deployment, we need to convert the pem file to PKCS12 format. Here is the command:

$ openssl pkcs12 -export -nokeys -in SERVER_CERT.pem -out SERVER_CERT.pfx

Note the option of "-nokeys". This means I do not have the private key of the certificate. Now we have server's certificates being taken care of. We need to convert the client's certificate to PKCS12. Here is the command to do so:

 openssl pkcs12 -export -in cacert.pem -inkey cakey.pem -out identity.p12 -name "mykey"

Note the above procedure will ask the password. Make sure you remember it.

Setup Mule Flow

The following diagram shows the simple Mule flow

The https request configuration is the following:

The import point here is that client's certificate is

and server's certificates is

How To Pass MuleSoft Certified Developer - Level 1 (Mule 4)

Congratulation Gary!

First of all, I must congratulate myself for getting this done. For almost a year, I have been thinking to take the exam, but my project schedules have been crazy. I hardly find time to prepare the certification. Three weeks ago, I decided to give a shot. I studied two weekends, and spend about 1 hour each day. And today, I did! I must say that I feel it is a kind of accomplishment. This test is not easy!

Here I will try to summarized my feeling about the test and how I prepared the test. Hopefully, it will provided some help to those who are thinking to take the test.

The Procedures

First of all, go to Mule training website and paid 250 USD online and schedule a test at the same time. I did my test at my local test center. There, I have to lock away my cell phone, watch, wallet, even my hat! It is very quiet and comfortable place. Not many people there either.

The exam is 2 hours long. That is plenty time to ponder each question carefully. At the first 10 minutes, MuleSoft did a survey about my experience in Mule, how I prepared the test, what role I play, etc. I am not sure why they should ask these questions at all. One thing really makes me suspicious is that if you are a very experience developer, you may get harder questions. It is just my guess!

How Was My Test Results?

It took me 88 minutes to submit the answer. I know I had plenty time, so that I read each question very carefully and did not plan to review them once I am done with all the questions.

The following are the results I got:

Creating Application Networks: 100.00%

Designing APIs: 100.00%

Building API Implementation Interfaces: 100.00%

Deploying and Managing APIs and Integrations: 75.00%

Accessing and Modifying Mule Events: 83.33%

Structuring Mule Applications: 66.66%

Routing Events: 80.00%

Handling Errors: 80.00%

Troubleshooting and Testing Mule Applications: 66.66%

Writing DataWeave Transformations: 100.00%

Using Connectors: 83.33%

Processing Records: 100.00%

Result: PASS

Roughly, my overall score is about 89%. I think I did pretty OK given that I did not have enough time to prepare. I have no idea why my trouble shooting score is only 66.66%. I thought this is my strongest area.

How Do I Feel About The Questions?

Overall, I think the questions are very good, but many of them are very hard to answer with confidence. About 15% of the questions are really hard.

The challenges come from several fronts. Firstly, most of the questions are very long. You must read the question at least two times before you answer the question. This really tests your English as the questions are very tricky. Secondly, most questions are really difficult to 100% sure from the first glance. You have to read them very carefully. Sometimes the brackets, comma, and semicolon make the difference. Thirdly, some questions are rare to encounter in real life, such as exporting artifacts from Anypoint Studio. We normally don't do this. All in all, I think MuleSoft training department did a good job. It seems the Mule 4 MCD is a bit harder the Mule 3 one.

How I Prepared My Test

I really don't have the time to go through all the training materials. Definitely no time to go through all the DIY.

Here is the procedure I took. I think if you are experience developer and want to pass the test at the first shot. You can follow my way.

1. Go to the final Quiz at the last Module of the training material, and try to answer them. They are pretty difficult actually. Many of them, I really had trouble to answer at the first time. The good news is that for each question, if you did not answer correctly, the website tell you the right answer. Thus you can figure out why.
2. Quickly go through each chapter and all the slides. Notes down what the chapter is about.
3. After the first two steps, I start to create many mini-code to really understand the details about connectors, error handling, different scopes, etc.
4. Take notes. Take a lot of notes. These notes really help me to remember the nitty-mitty details. Remember, to pass the test, you must pay attention to tiny details.

Some Thoughts About The Certification

Definitely, it worths the time and energy to prepare and take the Exam. It really lets us to start paying attention to details and try to think about the reason about the way MuleSoft implements connectors, design patterns, and other systems. It is not for beginner anyway.

Don't take the delta test. To me, it is really better to challenge ourselves and take Mule 4 MCD.

The questions have a lot of room to improve.

• It should really focus on how our daily development works.
• Questions should more focus on development of Mule flows, less memorization of syntaxes.
• More questions on design and troubleshooting.
• More questions on problem solving skills.

Mule 4: Enable HTTPS Connector Using openssl

Introduction

This article demonstrate the procedures using openssl to generate self-signed certificates, and how to use the private key to configure HTTPS connector.

Generate Private Key And Public Cert Using openssl

$ openssl req -newkey rsa:2048 -x509 -keyout cakey.pem -out cacert.pem -days 3650
Generating a RSA private key
....+++++
...................................................+++++
writing new private key to 'cakey.pem'
Enter PEM pass phrase:
Verifying - Enter PEM pass phrase:
-----
You are about to be asked to enter information that will be incorporated
into your certificate request.
What you are about to enter is what is called a Distinguished Name or a DN.
There are quite a few fields but you can leave some blank
For some fields there will be a default value,
If you enter '.', the field will be left blank.
-----
Country Name (2 letter code) [XX]:US
State or Province Name (full name) []:Texas
Locality Name (eg, city) [Default City]:Dallas
Organization Name (eg, company) [Default Company Ltd]:GGL Consulting Inc
Organizational Unit Name (eg, section) []:EA
Common Name (eg, your name or your server's hostname) []:Gary Liu
Email Address []:gary.liu1119@gmail.com

The above command will generate two files:

1. cakey.pem
2. cacert.pem

Mulesoft HTTPS TLS configuration support 3 format:

1. JKS -- Java Keystore
2. PKCS12 -- for details refer this page
3. JCEKS -- Stands for Java Cryptography Extension KeyStore

We need to convert the RAS format to PKCS12 using the following command:

$ openssl pkcs12 -export -in cacert.pem -inkey cakey.pem -out identity.p12 -name "mykey"
Enter pass phrase for cakey.pem:
Enter Export Password:
Verifying - Enter Export Password:

The above command generate a file namely: identity.p12 with the alias mykey. Now we can configure the HTTPS Connector.

Configure HTTPS Connector

The xml configuration will be like the following:

The follow snapshots show the procedures using Anypoint Studio:

Invoke The Service

To test the service we can use the following curl command:

$ curl -k -XGET https://localhost/helloworld
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100    31  100    31    0     0     31      0  0:00:01  0:00:01 --:--:--    29
{
  "message": "Hello, World"
}

Note -k option is to tell curl to accepted self-signed certificates.

Dataweave Tricks: Extract Keys and Values From HashMap

Introduction

I have a requirement to extract the keys and values from a dataset like the following:

{
  "account1" : {
      "accountID" : "1234",
      "name" : "Mary Loo",
      "balance" : 234.32
     },
  "account2" : {
      "accountID" : "1234",
      "name" : "Lauren Flor",
      "balance" : 234.32
     },
  "account3" : {
      "accountID" : "1234",
      "name" : "Mary Loo",
      "balance" : 234.32
     }         
}

Apparently, the above data is a Map. Now we need to produce two dataset of values and keys from the input (Map) as the following:

[
    {
        "accountID": "1234",
        "name": "Mary Loo",
        "balance": 234.32
    },
    {
        "accountID": "1234",
        "name": "Lauren Flor",
        "balance": 234.32
    },
    {
        "accountID": "1234",
        "name": "Mary Loo",
        "balance": 234.32
    }
]

and

[
    "account1",
    "account2",
    "account3"
]

Understanding Dataweave pluck Function

Dataweave has devised a function particularly for this kind of requirement. Here is the solution to extract values of a HashMap

%dw 2.0
output application/json
---
payload pluck (item, key, index) -> item

The shorthand version:

%dw 2.0
output application/json
---
payload pluck $

And to extract the keys:

%dw 2.0
output application/json
---
payload pluck (item, key, index) -> key

The shorthand version:

%dw 2.0
output application/json
---
payload pluck $$

Dataweave 2.0 Tricks: Sorting and Grouping

The Challenges

I have Accounts retrieved from Salesforce like the following:

[
    {
        "LastModifiedDate": "2015-12-09T21:29:01.000Z",
        "Id": "0016100000Kngh3AAB",
        "type": "Account",
        "Name": "AAA Inc."
    },
    {
        "LastModifiedDate": "2015-12-09T20:16:47.000Z",
        "Id": "0016100000KnXKhAAN",
        "type": "Account",
        "Name": "AAA Inc."
    },
    {
        "LastModifiedDate": "2015-12-12T02:06:48.000Z",
        "Id": "0016100000KqonvAAB",
        "type": "Account",
        "Name": "AAA Inc."
    },
...
]

The dataset contains many accounts which have the same name. These accounts with the same account are regarded as duplicates Eventually I want to delete the duplicates and just leave one in the SFDC. Before I delete the duplicates, I need to create an output for review like the following:

{
    "AAA Inc.": [
        "0016100000Kngh3AAB",
        "0016100000KnXKhAAN",
        "0016100000KqonvAAB",
        "0016100000KnggyAAB",
        "0016100000KngflAAB",
        "0016100000KqalVAAR",
        "0016100000Kngh8AAB",
        "0016100000KnVUKAA3",
        "0016100000Kngh5AAB",
        "0016100000KnVXdAAN",
        "0016100000KnVh4AAF",
        "0016100000KnVs6AAF",
        "0016100000KnggAAAR",
        "0016100000KnlokAAB",
        "0016100000KnggKAAR"
    ],
    "Adam Smith": [
        "0016100000L7sDjAAJ"
    ],
    "Alice John Smith": [
        "0016100000L7x29AAB"
    ],
    "Alice Smith.": [
        "0016100000L7sDiAAJ"
    ],
...

Solutions

I device a two-stage solution. The first transform will create LinkedHashMap which will contain account name as key and the value as array of Account as shown below:

%dw 2.0
output application/java
---
//payload groupBy $.Name orderBy $$
(payload groupBy (account) -> account.Name)  orderBy (item, key) -> key

The second stage of transformation is to extract the account ID as the following:

%dw 2.0
output application/java
---
payload mapObject (item, key, index) -> {  
 (key) : (item map (value) -> value.Id)  
}

Of course, I can put the two Dataweave scripts into one like the following:

%dw 2.0
output application/java
---
//payload groupBy $.Name orderBy $$
((payload groupBy (account) -> account.Name)  orderBy (item, key) -> key)
mapObject (item, key, index) -> {  
 (key) : (item map (value) -> value.Id)  
}

Key Learnings

The key concept of the above use case is to group the accounts with the same name and sort them in alphabetic order. The Mulesoft document about the groupBy and orderBy together with other core functions of dataweave can be found here The groupBy and orderBy have the similar signature:

1. groupBy(Array, (item: T, index: Number) -> R): { (R): Array }
2. groupBy({ (K)?: V }, (value: V, key: K) -> R): { (R): { (K)?: V } }
3. groupBy(Null, (Nothing, Nothing) -> Any): Null

The first function indicates that it can take array as input. The usage will like the following:

//payload groupBy $.Name
//payload groupBy (account, index) -> account.Name
payload groupBy (account) -> account.Name

The above code are the same. The first one is a short-cut version. The second and third lines are to show the lambda style. As a good developer, you should know all the syntax.

In my solution of the second stage, I use mapObject function as the following:

payload mapObject (item, key, index) -> {  
 (key) : (item map (value) -> value.Id)  
}

This is because the payload is a LinkedHashMap and the value of each HashMap entry is an array. That is why I have to use map function inside the mapObject function.

In my work, I also need to remove the type attribute in the Account object.

[
    {
        "LastModifiedDate": "2015-12-09T21:29:01.000Z",
        "Id": "0016100000Kngh3AAB",
        "type": "Account",
        "Name": "AAA Inc."
    },
...
]

Here is the transform to remove the type:

(payload orderBy (item) -> item.Name) map (account) -> {
 (account -- ['type'])
}

As you can see I have used function of --.

Summary

The key thinking of solve this kind of problem how to group, sort, and extract values from the Array or LinkedHashMap. Thus I have used the following core Dataweave functions:

• groupBy
• orderBy
• map
• mapObject

Also, we should know the short-hand way and Lambda style for using the Dataweave functions. The short-hand way is to use build-in variable $, $$, $$$.
If the payload is Array

• $ - item
• $$ - index

If the payload is LinkedHashMap

• $ - value
• $$ - key
• $$$ - index.

The Lambda style is like the following:

(payload orderBy (item) -> item.Name) map (account, index) -> {
 (account -- ['type'])
}

mapObject (item, key, index) -> {  
 (key) : (item map (value) -> value.Id)  
}

Mule Application Hacking: Reveal Details Of A Connector's Connection

Introduction

In my last hacking post, I described the method to view the source code of Mule connectors using the ECD. In this article, I am go demonstrate the procedure to reveal the details about connection and communication within the Mule Connector. This is very useful for the purpose of trouble-shooting.

I will use Salesforce connector as example to demonstrate how to read connection details, query, etc.

Details

First, looking for the connector as shown in the following snapshots:

As you can see, I have added Salesforce connection version 9.7.7. Now, we need to expand the connector. Then looking for mule-salesforce-connector-9.7.7-mule-pluging.jar and expand the jar file as shown below:

Now we can see that the java class packages all under org.mule.extension.salesforce.

The next step is to add the package to log4j.xml in the dir of src/main/resources as shown below:

Now add the package of org.mule.extension.salesforce into the Loggers section of the log4j.xml file as shown below

Now, if you run the project, the console will deplay the debugging information about the connection information, request, and response from Salesforce connectors.

Hacking Mule Application - View Source Code

Introduction

To become a real good Mule developer, we need to understand the source code of Mule connectors, components, and other internal source code. This helps us to learn the internal data model and interfaces of Mule classes. I have written a blog on how to compile and install the ECD in Anypoint Studio. However, that building system is broken for Mule 4. Hopefully, it will be fixed soon.

This article demonstrate another way to view the source code. It is not the best solution yet, but it help. The idea is to use Eclipse IDE and ECD plugin to review the java source code.

ECD is so far the best Java Decompiler available for Eclipse. The details can be found at here

Install Eclipse & ECD Plugin

First download the Eclipse EE from this site. Second, create a java project. Third, install ECD Eclipse Plugin. go to Eclipse Market Place of ECD
Drag the install to your project.

Now to preferences, you should see the Decompiler under Java as shown belog:

Fourth, import jar archive. right click the project --> select Achive File

browser the file from your local maven repository. In my case, it is at .m2/repository/org/mule/connectors/mule-http-connector/1.5.3.
Import the jar file to the newly created project. Drill down the classed you are interested as shown in the following snapshot:

Note that you have to chose the decompiler by right click java class --> open with, select as shown below:

At this point, we can review the source code. The next step is to decompiler the whole jar file and rebuild it with source. In this we can debug the source code and modify the behavior of the connectors. I will cover the procedure later.

SSL Handshake Failure Connecting To Mulesooft Anypoint Exchange In Corporate Environment

The Issue

As a Mulesoft developer, we will need to download connectors from Anypoint exchange periodically. When we try to connect to Mulesoft Anypoint Exchange, which is the repository for Mulesoft related connectors and other libraries, we may get SSH Handshake exception, in particular, using corporate provided laptop. Here is the top part of the exception message:

eclipse.buildId=unknown
java.version=1.8.0_212
java.vendor=Oracle Corporation
BootLoader constants: OS=win32, ARCH=x86_64, WS=win32, NL=en_US
Command-line arguments:  -os win32 -ws win32 -arch x86_64

org.mule.tooling.core
Error
Thu Jul 11 17:49:09 CDT 2019
The following exceptions were encountered while resolving dependency com.mulesoft.connectors:mule-salesforce-connector:9.7.6: java.lang.RuntimeException: There was an issue resolving the dependency tree for the bundleDescriptors [[BundleDescriptor{groupId='com.mulesoft.connectors', artifactId='mule-salesforce-connector', baseVersion='null', version='9.7.6', type='jar', classifier=Optional[mule-plugin]}, BundleDescriptor{groupId='org.mule.connectors', artifactId='mule-objectstore-connector', baseVersion='null', version='1.0.0', type='jar', classifier=Optional[mule-plugin]}]]
 at org.mule.maven.client.internal.AetherMavenClient.resolvePluginBundleDescriptorsDependencies(AetherMavenClient.java:322)
 at org.mule.tooling.core.m2.internal.MuleMavenClientResolver.resolvePluginDependencies(MuleMavenClientResolver.java:80)
 at org.mule.tooling.core.module.internal.runner.DownloadTask.doRun(DownloadTask.java:76)
 at org.mule.tooling.core.module.internal.runner.Task.run(Task.java:65)
 at org.mule.tooling.core.module.internal.runner.DownloadTask.run(DownloadTask.java:1)
 at org.mule.tooling.core.module.internal.runner.ArtifactResolvingRunner$ArtifactJob.run(ArtifactResolvingRunner.java:212)
 at org.eclipse.core.internal.jobs.Worker.run(Worker.java:56)
Caused by: org.eclipse.aether.collection.DependencyCollectionException: Failed to collect dependencies at com.mulesoft.connectors:mule-salesforce-connector:jar:mule-plugin:9.7.6 -> com.mulesoft.connectors:mule-connector-commons:jar:2.1.1
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.collectDependencies(DefaultDependencyCollector.java:291)
 at org.eclipse.aether.internal.impl.DefaultRepositorySystem.collectDependencies(DefaultRepositorySystem.java:316)
 at org.mule.maven.client.internal.AetherMavenClient.doResolveDependencies(AetherMavenClient.java:408)
 at org.mule.maven.client.internal.AetherMavenClient.resolvePluginBundleDescriptorsDependencies(AetherMavenClient.java:314)
 ... 6 more
Caused by: org.eclipse.aether.resolution.ArtifactDescriptorException: Failed to read artifact descriptor for com.mulesoft.connectors:mule-connector-commons:jar:2.1.1
 at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.loadPom(DefaultArtifactDescriptorReader.java:282)
 at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.readArtifactDescriptor(DefaultArtifactDescriptorReader.java:198)
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.resolveCachedArtifactDescriptor(DefaultDependencyCollector.java:535)
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.getArtifactDescriptorResult(DefaultDependencyCollector.java:519)
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.processDependency(DefaultDependencyCollector.java:409)
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.processDependency(DefaultDependencyCollector.java:363)
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.process(DefaultDependencyCollector.java:351)
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.doRecurse(DefaultDependencyCollector.java:504)
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.processDependency(DefaultDependencyCollector.java:458)
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.processDependency(DefaultDependencyCollector.java:363)
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.process(DefaultDependencyCollector.java:351)
 at org.eclipse.aether.internal.impl.DefaultDependencyCollector.collectDependencies(DefaultDependencyCollector.java:254)
 ... 9 more
Caused by: org.eclipse.aether.resolution.ArtifactResolutionException: Could not transfer artifact com.mulesoft.connectors:mule-connector-commons:pom:2.1.1 from/to mulesoft-releases (https://repository.mulesoft.org/releases/): sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target
 at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolve(DefaultArtifactResolver.java:444)
 at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolveArtifacts(DefaultArtifactResolver.java:246)
 at org.eclipse.aether.internal.impl.DefaultArtifactResolver.resolveArtifact(DefaultArtifactResolver.java:223)
 at org.apache.maven.repository.internal.DefaultArtifactDescriptorReader.loadPom(DefaultArtifactDescriptorReader.java:267)
 ... 20 more

This article describes the procedures to fix this kind of issues.

Find The Root Cause

Problems solving skills are really about to find the root cause of the issue. In this issue, if we look the error message carefully, we will find the following:

Caused by: org.eclipse.aether.resolution.ArtifactResolutionException: Could not transfer artifact com.mulesoft.connectors:mule-connector-commons:pom:2.1.1 from/to mulesoft-releases (https://repository.mulesoft.org/releases/): sun.security.validator.ValidatorException: PKIX path building failed: sun.security.provider.certpath.SunCertPathBuilderException: unable to find valid certification path to requested target

What this error message is saying that Java process was trying to transfer data from host of: repository.mulesoft.org. The problem is the SSL Handshake. To resolve this kind of problem we need to import the certificate from the site to cacerts.

Tasks

In this article, I only import 3 certificates from the following site:

• anypoint.mulesoft.com
• maven.anypoint.mulesoft.com
• release.anypoint.mulesoft.com

Prerequisites

1. On Windows install Cygwind
2. Have Admin privilege of the laptop

Solutions

When we connect to Mulesoft Anypoint Exchange, AnypointStudio needs to go through SSL Handshake procedure before we can see the download page. If this process failed, typically, AnypointStudio (a java process) could not store the certificate), the SSHHandshakeException will be thrown by the studio. The following steps will fix the issue:

Step One: Download certificate from anypoint.mulesoft.com

openssl s_client -connect anypoint.mulesoft.com:443 -showcerts </dev/null 2>/dev/null |openssl x509 -outform PEM >anypoint.pem

Step Two: Download certificate from maven.anypoint.mulesoft.com

openssl s_client -connect maven.anypoint.mulesoft.com:443 -showcerts   </dev/null 2>/dev/null | openssl x509 -outform PEM >mulesoft.maven.pem

Step Three: Download certificate from repository.anypoint.mulesoft.com

openssl s_client -connect repository.mulesoft.org:443 -showcerts   </dev/null 2>/dev/null | openssl x509 -outform PEM >mulesoft.repo.pem

Step Four: Copy the 3 certificates

cp *.pem /cygdrive/c/’Program Files’/Java/jdk1.8.0_212/jre/lib/security

As you can see that I am using cygwin on Windows. On Macbook Pro, the JAVA_HOME is may be different. In this case the JAVA_HOME is under:

/cygdrive/c/’Program Files’/Java/jdk1.8.0_212

Step Five: Import the certificate to cacerts

/cygdrive/c/’Program Files’/Java/jdk1.8.0_212/jre/lib/security
keytool -import -alias anypoint -keystore cacerts -file anypoint.pem

Repeat the same procedure for the other 2 certificaes. Step Fix: Restart Anypoint Studio