def image_name = "dpedu/photolib"

pipeline {
    agent {
        kubernetes {
            yaml """
apiVersion: v1
kind: Pod
spec:
  podAntiAffinity:
    preferredDuringSchedulingIgnoredDuringExecution:  # avoid nodes already running a jenkins job
    - podAffinityTerm:
        labelSelector:
          matchExpressions:
          - key: jenkins
            operator: In
            values:
            - slave
        topologyKey: node
  containers:
  - name: docker
    image: docker:20-dind
    args:
      - "--insecure-registry"
      - "dockermirror:5000"
    securityContext:
      privileged: true
"""
        }
    }
    stages {
        stage("Build image") {
            steps {
                container("docker") {
                    script {
                        try {
                            docker.withRegistry('http://dockermirror:5000') {
                                docker.image("ubuntu:focal").pull()
                                docker.image(image_name).pull() // Pull a recent version to share base layers with (?)
                            }
                        } catch (exc) {
                            echo "couldn't pull image, assuming we're building it for the first time"
                        }
                        docker.build(image_name)
                    }
                }
            }
        }
        stage("Push image") {
            steps {
                container("docker") {
                    script {
                        docker.withRegistry('http://dockermirror:5000') {
                            image_tag = env.BRANCH_NAME == "master" ? "latest" : env.BRANCH_NAME.replace("/", "--")
                            docker.image(image_name).push(image_tag)
                        }
                    }
                }
            }
        }
        stage("Show images") {
            steps {
                container("docker") {
                    sh 'docker images'
                }
            }
        }
    }
}