Executing Docker commands with Gradle

Question

I would like to run some docker commands such as

docker login -u foo -p bar myregistry
docker build --pull=true -t myregistry/myimage path/to/dockerfile
docker push myregistry/myimage

I have tried several plugins for it such as this one, but none of those was satisfying, or maybe I am missing something...

My question is, what is the best way to run docker commands inside of my gradle tasks

Here is my build.gradle file and what I would like him to do

import GenerateDockerFile

apply plugin : 'groovy'

repositories {
    mavenCentral()
    jcenter()
}

dependencies {
    compile 'org.codehaus.groovy:groovy-all:2.4.7'
    compile localGroovy()
    compile gradleApi()
    classpath 'com.bmuschko:gradle-docker-plugin:3.0.1'
}

def copyFiles() {
    //Some stuff
}

def versionNumber(){
    //Some stuff    
}

def clean(){
   exec {
        executable "sh"
        args "-c", "ls"
    }
}
}

task build (){

    copyFiles()

    versionNumber()

    def version = new File('tmp_version').text
    def buildTag= ""
    if (project.hasProperty('args')) {
      buildTag = args
    }
    else{
      buildTag = System.console().readLine 'Enter a build tag'
    }


    println "\nGenerating DockerFile for version $version with build tag $buildTag"

    GenerateDockerFile.configure(version, buildTag);

    println 'DockerFile generated'

    //Execute docker commands here
    // docker login ....

    doLast {
        clean()
    }
}

If possible, something like the exec sh like in the clean method would be perfect. However, if a plugin can easily do this, it's ok too

Answer 1

I have not tried it out, but how about following suggestion, inspired by the answer on Run shell command in gradle but NOT inside a task and by the discussion on https://discuss.gradle.org/t/how-to-execute-shell-command-source-or-dot-doesnt-work-with-exec/7271/9?

For running the two commands

docker login localhost:8080
docker build .

you could try with:

def runDockerLogin(String target) {
    exec {
        executable "docker"
        args "login", target
    }
}

def runDockerBuild(String target) {
    exec {
        executable "docker"
        args target
    }
}

task doIt {
    doLast {
        runDockerLogin("localhost:8080")
        runDockerBuild(".")
    }
}

Note that the args need to be specified in lists. E.g. if you want to issue a command like

docker build -t fail .

using runDockerBuild, then I expect that

runDockerBuild("-t fail .")

will not work. Instead, runDockerBuild could be re-written to something like

def runDockerBuild(String target) {
   exec {
        executable "docker"
        args "-t", "fail", target
    }
}

Is this pointing in the right direction?