# Build and publish images with docker/podman

## SYNOPSIS

```gradle

plugins {
    id 'org.implab.gradle-container'
}

container {
    // if you want to use podman
    cliCmd = "podman"
}

configurations {
    app
}

dependencies {
    // the application that needs to be built and packed
    app project(":server")
}

// add custom task to copy application files
// to the docker build context.
task copyApp(type: Copy) {
    processResources.dependsOn it

    into container.contextDirectory.dir("root/opt/myapp")
    from configurations.app
}

task printVersion {
    doLast {
        println "tag: ${buildImage.imageTag.get()}"
        println "archive: ${saveImage.archiveFileName.get()}"
    }
}


```

## Description

This plugin is a simple wrapper around docker CLI. All the image
building process is deligated to the `Dockerfile` which will run
in the prepeared build context.

### Project structure

* `build/`
  * `context/` - the build context where `docker build` command will run.
  * `imageid` - the file storing the id of the image has been built.
  * `image-name-1.2.3.tgz` - the exported image if `saveImage` has been executed.
* `src`
  * `main` - the source files which will be copied to the build context.

## Properties

`imagesAuthority` - the registry where the image should be published.
for example `docker.io`

`imagesGroup` - the path to the image in the repository.

## Tasks

### buildImage

The task builds the image. Wrapper around the `docker build` command.

### saveImage

The task exports image as the .tar archive.

### pushImage

The task pushes the image to the remote repository.

### processResources

The copy task, it prepares the build context use it to customize
the build context.