Drone.io plugin to build images with s2i

Source to image, aka "s2i", is a Red Hat project originaly created to build images from sources without the need of a Dockerfile, made for Openshit/OKD (see https://www.openshift.com/ and the community version https://www.okd.io/). It is possible to create multi-stage or "chained" images, to create runtime-images with a small footprint.

Drone is a CI/CD solution that can run on Docker and Kubernetes.

To be able to have the same build solution, you need this plugin.

Before using this plugin, please make sure that you know how is working "source to image".

Usage

In your .drone.yml file, you can use some-repo/drone-s2i-builder - you can use these paramters:

• builder_image (mandatory) is the "s2i" image that is used to build the sources
• push (boolean, default to false) will push your image to target_image after the build
• target_image (mandatory if push is true) is the target-image that is created by the s2i build-process
• source (defaults to DRONE_WORKSPACE_BASE) Path to the sources.
• extract (boolean, default to false) will extract parts of the built-image to a cache_dir directory
• extract_path (mandatory if extract is true) is the path of the build-output image that will be extracted
• cache_dir (mandatory if extract is true) is the temporary path where extract_path will be stored
• inject_dir an optional directory that will be injected into the s2i-build container
• env_vars (array of KEY=VAL) env-variables that will be passed into the s2i-build container
• context (string, default to "./") is the context directory inside your repository
• registry is the registry you want to login
• insecure (boolean, default to false) to use the registry as "insecure" (http instead of https)
• username if set with password, try to authenticate registry with that user
• password is the password used to authenticate user
• cert (optional) is the base64 encoded certificate to write in /etc/docker/certs.d/${registry}/ca.crt where registry is the corresponding parameter. One more time, please use a secret to store the certificate.

The following example will perform a multi-stage build with s2i.

• First step: Build Angular webapp with node-js s2i image and extract the comiled output to a temporary directory which is shared in the pipeline
• Second step: Take the build-output of the first step as input for another s2i step that build a nginx-image with the compiled application

It is easy to add intermediate steps that perform some actions with the extracted code

kind: pipeline
name: default

steps:

  - name: s2i-build-angular
    image: some-repo/drone-s2i-builder:latest
    volumes:
    - name: cache
      path: /drone/cache
    - name: dockersock
      path: /var/run
    pull: always
    settings:
      builder_image: registry.access.redhat.com/ubi8/nodejs-16-minimal:1-14 
	    extract: true
	    extract_path: /opt/app-root/src/dist/my-app
	    cache_dir: /drone/cache
      target: docker-registry:5000/witcom/webapp
  - name: s2i-build-nginx
    image: some-repo/drone-s2i-builder:latest
    volumes:
    - name: cache
      path: /drone/cache
    - name: dockersock
      path: /var/run
    pull: always
    settings:
      builder_image: registry.access.redhat.com/ubi9/nginx-120
	    push: true
	    source: /drone/cache
      target_image: docker-registry:5000/witcom/webapp
      tags:
        - latest
        - ${DRONE_TAG}
      user:
        from_secret: registry-username
      password:
        from_secret: registry-password

services:
- name: docker
  image: docker:dind
  privileged: true
  volumes:
  - name: dockersock
    path: /var/run

volumes:
- name: cache
  temp: {}
- name: dockersock
  temp: {}

Docker-in-docker

As we need a docker daemon to be launched, we use a docker-in-docker instance which is started as a privileged service.

To avoid that, you can add the docker:dind image to DRONE_RUNNER_PRIVILEGED_IMAGES:

DRONE_RUNNER_PRIVILEGED_IMAGES=plugins/docker,plugins/ecr,docker:dind

That way, you will not need to set privileged mode, and others users will be able to build images with s2i.