Flutter Jenkins flutter not found issue

I am currently trying to build a Flutter app with Jenkins. For the initial setup I have a master-slave setup in which the slave is a Mac machine which will create the build (slave machine is connected as well).

Below is the pipeline script:


pipeline {
    agent {
        label "macos16Node"
    }
     environment {
        flutter = " /Users/username/Desktop/flutter"
    }


    stages {
        stage ('Flutter Doctor') {
            steps {
                withEnv(['PATH+EXTRA=/opt/flutter/bin']){
                    sh '$flutter doctor -v'
                }
               
            }
           
        }
        stage('GIT PULL') {
            steps {a
                git branch: 'main', credentialsId: 'github_token', url: ‘mygitrepo’
            }
        }
        stage('TEST') {
            steps {
                
                    sh ‘$flutter test'
                
                
            }
        }
        stage('BUILD') {
            steps {
                sh '''
                  #!/bin/sh
                  flutter build apk --debug
                  '''
            }
        }
        
    }
}

Whenever I build the pipeline it gives me an error.

Following is the console output:

[Pipeline] Start of Pipeline
[Pipeline] node
Running on slaveNode in /var/root/workspace/first pipeline
[Pipeline] {
[Pipeline] withEnv
[Pipeline] {
[Pipeline] stage
[Pipeline] { (Flutter Doctor)
[Pipeline] withEnv
[Pipeline] {
[Pipeline] sh
+ /Users/user/Desktop/flutter doctor -v
/var/root/workspace/first pipeline@tmp/durable-f6dbaa4a/script.sh: 1: /Users/user/Desktop/flutter: not found

I have also not set any path in the env variables in Jenkins. Why does it not detect Flutter, do I need and additional setup for this?

Solution

Quick answer

Reason:

flutter binary is not the in the PATH of jenkins shell

Fix:

Download flutter anywhere like /tmp/workspace/flutter and override the PATH in the environment.

Jenkins 2.375.2

pipeline {
    agent any
    environment {
      PATH = "$PATH:/tmp/workspace/flutter/bin"
    }    
    stages {
        stage('Setup') {
            steps {
                print "${env.PATH}"
            }    
        }
        
        stage('Build') {
            steps {
                sh "flutter doctor -v"
            }
        }        
    }
}

output

Detailed answer

There is no magic with Jenkins, if it works in the shell, it will work with Jenkins.

Steps 1: Add flutter to the shell PATH

In the machine which jenkins will execute the build commands, try the command flutter doctor -v. You will see this error:

Similar to the jenkins error

So, install flutter with snap

sudo snap install flutter --classic

or download it with curl

curl https://storage.googleapis.com/flutter_infra_release/releases/stable/linux/flutter_linux_3.7.3-stable.tar.xz -o /foo/bar/flutter.tar.xz
apt-get install xz-utils
tar xf /foo/bar/flutter.tar.xz

You should have these files ls -la /foo/bar/flutter

Finally you need to add the flutter to the shell PATH variable. You could use the java style

export FLUTTER_HOME=/foo/bar/flutter
export PATH=$PATH:$FLUTTER_HOME/bin

If you run the command, it will work

Steps 2: Add flutter to the jenkins PATH

For declarative pipeline, since PATH is a special env var, the only way to modify it is with:

environment {
  PATH = "$PATH:/foo/bar/flutter/bin"
}

Similar to the host shell example PATH=$PATH:$FLUTTER_HOME/bin

After that, you could use flutter anywhere of your pipeline

For scripted pipeline, these 2 options worked for me:

#1 Modifying the PATH variable

node {   
  print "${env.PATH}"

  def FLUTTER_HOME = "/tmp/workspace/flutter"
  env.PATH = env.PATH+":$FLUTTER_HOME/bin"
  print "${env.PATH}"

  sh "flutter doctor -v"
}

#2 withEnv PATH+EXTRA

node {
  def FLUTTER_HOME = "/tmp/workspace/flutter"

  withEnv(["PATH+EXTRA=$FLUTTER_HOME/bin"]){
    sh 'flutter doctor -v'
  }

  sh "flutter doctor -v"
}

The only problem with this latest option is that flutter will work only in the withEnv{...} scope.

Flutter Jenkins flutter not found issue

Quick answer

Detailed answer

Steps 1: Add flutter to the shell PATH

Steps 2: Add flutter to the jenkins PATH

References