Using Concourse CI to Deploy to Docker Swarm

In this tutorial we will use Concourse to Deploy our application to Docker Swarm.

The Flow

• Our application code resides on Github
• The pipeline triggers when a commit is pushed to the master branch
• The pipeline will automatically deploy to the staging environment
• The pipeline requires a manual trigger to deploy to prod
• Note: Staging and Prod on the same swarm for demonstration

The code for this tutorial is available on my github repository

Application Structure

The application structure for our code looks like this:

Pipeline Walktrough

Our ci/pipeline.yml

resources:
  - name: main-repo
    type: git
    source:
      uri: git@github.com:ruanbekker/concourse-swarm-app-demo.git
      branch: master
      private_key: ((github_private_key))

  - name: main-repo-staging
    type: git
    source:
      uri: git@github.com:ruanbekker/concourse-swarm-app-demo.git
      branch: master
      private_key: ((github_private_key))
      paths:
        - config/staging/*

  - name: main-repo-prod
    type: git
    source:
      uri: git@github.com:ruanbekker/concourse-swarm-app-demo.git
      branch: master
      private_key: ((github_private_key))
      paths:
        - config/prod/*

  - name: slack-alert
    type: slack-notification
    source:
      url: ((slack_notification_url))

  - name: version-staging
    type: semver
    source:
      driver: git
      uri: git@github.com:ruanbekker/concourse-swarm-app-demo.git
      private_key: ((github_private_key))
      file: version-staging
      branch: version-staging

  - name: version-prod
    type: semver
    source:
      driver: git
      uri: git@github.com:ruanbekker/concourse-swarm-app-demo.git
      private_key: ((github_private_key))
      file: version-prod
      branch: version-prod

resource_types:
  - name: slack-notification
    type: docker-image
    source:
      repository: cfcommunity/slack-notification-resource
      tag: v1.3.0

jobs:
  - name: bump-staging-version
    plan:
    - get: main-repo-staging
      trigger: true
    - get: version-staging
    - put: version-staging
      params:
        bump: major

  - name: bump-prod-version
    plan:
    - get: main-repo-prod
      trigger: true
    - get: version-prod
    - put: version-prod
      params:
        bump: major

  - name: deploy-staging
    plan:
    - get: main-repo-staging
    - get: main-repo
    - get: version-staging
      passed:
      - bump-staging-version
      trigger: true
    - task: deploy-staging
      params:
        DOCKER_SWARM_HOSTNAME: ((docker_swarm_staging_host))
        DOCKER_SWARM_KEY: ((docker_swarm_key))
        DOCKER_HUB_USER: ((docker_hub_user))
        DOCKER_HUB_PASSWORD: ((docker_hub_password))
        SERVICE_NAME: app-staging
        SWARM: staging
        ENVIRONMENT: staging
        AWS_ACCESS_KEY_ID: ((aws_access_key_id))
        AWS_SECRET_ACCESS_KEY: ((aws_secret_access_key))
        AWS_DEFAULT_REGION: ((aws_region))
      config:
        platform: linux
        image_resource:
          type: docker-image
          source:
            repository: rbekker87/build-tools
            tag: latest
            username: ((docker_hub_user))
            password: ((docker_hub_password))
        inputs:
        - name: main-repo-staging
        - name: main-repo
        - name: version-staging
        run:
          path: /bin/sh
          args:
            - -c
            - |
              ./main-repo/ci/scripts/deploy.sh
      on_failure:
        put: slack-alert
        params:
          channel: '#system_events'
          username: 'concourse'
          icon_emoji: ':concourse:'
          silent: true
          text: |
            *$BUILD_PIPELINE_NAME/$BUILD_JOB_NAME* ($BUILD_NAME) FAILED :rage: - TestApp Deploy to staging-swarm failed
            http://ci.example.local/teams/$BUILD_TEAM_NAME/pipelines/$BUILD_PIPELINE_NAME/jobs/$BUILD_JOB_NAME/builds/$BUILD_NAME
      on_success:
        put: slack-alert
        params:
          channel: '#system_events'
          username: 'concourse'
          icon_emoji: ':concourse:'
          silent: true
          text: |
            *$BUILD_PIPELINE_NAME/$BUILD_JOB_NAME* ($BUILD_NAME) SUCCESS :aww_yeah: - TestApp Deploy to staging-swarm succeeded
            http://ci.example.local/teams/$BUILD_TEAM_NAME/pipelines/$BUILD_PIPELINE_NAME/jobs/$BUILD_JOB_NAME/builds/$BUILD_NAME

  - name: deploy-prod
    plan:
    - get: main-repo-prod
    - get: main-repo
    - get: version-prod
      passed:
      - bump-prod-version
    - task: deploy-prod
      params:
        DOCKER_SWARM_HOSTNAME: ((docker_swarm_prod_host))
        DOCKER_SWARM_KEY: ((docker_swarm_key))
        DOCKER_HUB_USER: ((docker_hub_user))
        DOCKER_HUB_PASSWORD: ((docker_hub_password))
        SERVICE_NAME: app-prod
        SWARM: prod
        ENVIRONMENT: production
        AWS_ACCESS_KEY_ID: ((aws_access_key_id))
        AWS_SECRET_ACCESS_KEY: ((aws_secret_access_key))
        AWS_DEFAULT_REGION: ((aws_region))
      config:
        platform: linux
        image_resource:
          type: docker-image
          source:
            repository: rbekker87/build-tools
            tag: latest
            username: ((docker_hub_user))
            password: ((docker_hub_password))
        inputs:
        - name: main-repo-prod
        - name: main-repo
        - name: version-prod
        run:
          path: /bin/sh
          args:
            - -c
            - |
              ./main-repo/ci/scripts/deploy.sh
      on_failure:
        put: slack-alert
        params:
          channel: '#system_events'
          username: 'concourse'
          icon_emoji: ':concourse:'
          silent: true
          text: |
            *$BUILD_PIPELINE_NAME/$BUILD_JOB_NAME* ($BUILD_NAME) FAILED :rage: - TestApp Deploy to prod-swarm failed
            http://ci.example.local/teams/$BUILD_TEAM_NAME/pipelines/$BUILD_PIPELINE_NAME/jobs/$BUILD_JOB_NAME/builds/$BUILD_NAME
      on_success:
        put: slack-alert
        params:
          channel: '#system_events'
          username: 'concourse'
          icon_emoji: ':concourse:'
          silent: true
          text: |
            *$BUILD_PIPELINE_NAME/$BUILD_JOB_NAME* ($BUILD_NAME) SUCCESS :aww_yeah: - TestApp Deploy to prod-swarm succeeded
            http://ci.example.local/teams/$BUILD_TEAM_NAME/pipelines/$BUILD_PIPELINE_NAME/jobs/$BUILD_JOB_NAME/builds/$BUILD_NAME

Our ci/credentials.yml which will hold all our secret info, which will remain local:

username: yourdockerusername
password: yourdockerpassword
docker_swarm_prod_host: 10.20.30.40
...

The first step of our deploy will invoke a shell script that will establish a ssh tunnel to the docker host, mounting the docker socket to a tcp local port, then exporting the docker host port to the tunneled port, ci/scripts/deploy.sh:

#!/usr/bin/env sh

export DOCKER_HOST="localhost:2376"

echo "${DOCKER_SWARM_KEY}" | sed -e 's/\(KEY-----\)\s/\1\n/g; s/\s\(-----END\)/\n\1/g' | sed -e '2s/\s\+/\n/g' > key.pem
chmod 600 key.pem

screen -S \
  sshtunnel -m -d sh -c \
  "ssh -oStrictHostKeyChecking=no -oUserKnownHostsFile=/dev/null -i ./key.pem -NL localhost:2376:/var/run/docker.sock root@$DOCKER_SWARM_HOSTNAME"

sleep 5
docker login -u "${DOCKER_HUB_USER}" -p "${DOCKER_HUB_PASSWORD}"
docker stack deploy --prune -c ./main-repo/ci/docker/docker-compose.${ENVIRONMENT}.yml $SERVICE_NAME --with-registry-auth

if [ $? != "0" ]
  then
    echo "deploy failure for: $SERVICE_NAME"
    screen -S sshtunnel -X quit
    exit 1
  else
    set -x
    echo "deploy success for: $SERVICE_NAME"
    screen -S sshtunnel -X quit
fi

The deploy script references the docker-compose files, first our ci/docker/docker-compose.staging.yml:

version: "3.4"

services:
  web:
    image: ruanbekker/web-center-name
    environment:
      - APP_ENVIRONMENT=Staging
    ports:
      - 81:5000
    networks:
      - web_net
    deploy:
      mode: replicated
      replicas: 2

networks:
  web_net: {}

Also, our docker-compose for production, ci/docker/docker-compose.production.yml:

version: "3.4"

services:
  web:
    image: ruanbekker/web-center-name
    environment:
      - APP_ENVIRONMENT=Production
    ports:
      - 80:5000
    networks:
      - web_net
    deploy:
      mode: replicated
      replicas: 10

networks:
  web_net: {}

Set the Pipeline in Concourse

Create 2 branches in your github repository for versioning: version-staging and version-prod, then logon to concourse and save the target:

$ fly -t ci login -n main -c http://<concourse-ip>

Set the pipeline, point the config, local variables definition and name the pipeline:

$ fly -t ci sp -n main -c ci/pipeline.yml -p <pipeline-name> -l ci/<variables>.yml

You will find that the pipeline will look like below and that it will be in a paused state:

Unpause the pipeline:

$ fly -t ci up -p swarm-demo

The pipeline should kick-off automatically due to the trigger that is set to true:

Deployed automatically to staging, prod is a manual trigger:

Testing our Application

For demonstration purposes we have deployed staging on port 81 and production on port 80.

Testing Staging on http://swarm-ip:81/

Testing Production on http://swarm-ip:80/

Thanks

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