packer.json

{
  "variables": {
    "name": "jenkins-gcp-leader",
    "git_commit": "",
    "git_branch": "",
    "account_file": "",
    "project_id": "null"
  },
  "builders": [
    {
      "type": "docker",
      "image": "jenkins:1.625.3",
      "run_command": ["-d", "-i", "-t", "-u", "root", "{{.Image}}", "/bin/bash"],
      "commit": "true" 
    }
  ],
  "provisioners": [
    {
      "type": "file",
      "source": "plugins.txt",
      "destination": "/usr/share/jenkins/plugins.txt"
    },
    {
      "type": "file",
      "source": "workflow-version.txt",
      "destination": "/usr/share/jenkins/workflow-version.txt"
    },
    {
      "type": "file",
      "source": "jenkins/jobs",
      "destination": "/usr/share/jenkins/ref"
    },
    {
      "type": "file",
      "source": "start.sh",
      "destination": "/usr/local/bin/start.sh"
    },
    {
      "type": "shell",
      "environment_vars" : [ "CLOUDSDK_CORE_DISABLE_PROMPTS=1" ],
      "inline": [
        "chmod +x /usr/local/bin/start.sh",
        "sed -i \"s/@VERSION@/`cat /usr/share/jenkins/workflow-version.txt`/g\" /usr/share/jenkins/plugins.txt",
        "/usr/local/bin/plugins.sh /usr/share/jenkins/plugins.txt",
        "apt-get update -y",
        "apt-get upgrade -y",
        "apt-get install -y -qq --no-install-recommends wget unzip python openssh-client rsync",
        "apt-get clean",
        "cd /usr/local/bin",
        "wget https://dl.google.com/dl/cloudsdk/release/google-cloud-sdk.zip",
        "unzip google-cloud-sdk.zip",
        "rm google-cloud-sdk.zip",
        "google-cloud-sdk/install.sh --usage-reporting=true --disable-installation-options",
        "google-cloud-sdk/bin/gcloud --quiet components update preview",
        "google-cloud-sdk/bin/gcloud --quiet config set component_manager/disable_update_check true",
        "ln -s /usr/local/bin/google-cloud-sdk/bin/gcloud /usr/local/bin/gcloud",
        "ln -s /usr/local/bin/google-cloud-sdk/bin/gsutil /usr/local/bin/gsutil"
      ]
    }
  ],
  "post-processors": [
    [
        {
            "type": "docker-tag",
            "repository": "gcr.io/{{user `project_id`}}/{{user `name`}}",
            "tag": "{{user `git_branch`}}-{{user `git_commit`}}",
            "only": ["docker"]
        }
    ]
  ]
}