Devops on Docker

This is probably your first Devops solution.

Quick start

Let me briefly describe the behavior that basic Devops should have:

Coding >> Commit >> Hooks >> Building >> Unit Testing >> Image Pushing >> Deploying

Obviously, Devops is composed of multiple systems. They carried out division of labor and cooperation, as well as pipelined operations, and finally achieved the results we wanted.

Therefore, I have selected several simple and lightweight open source projects in the open source community to form our Devops components.

Gitea

As a private GIT repository, Gitea is portable enough, it has only one binary file, and all the functions are carried in a size less than 60MB.

Deploying

docker-compose -f ./Gitea/docker-compose.yaml up -d

Registry

As a private docker registry, this is also the official open source private registry solution of docker. In addition, you have no choice. :(

Need to configure according to your environment before deployment

Deploying

docker-compose -f ./Registry/docker-compose.yaml up -d

Drone

Now, we need a CI/CD platform to mobilize tasks. Here I choose Drone CI.

It also depends on the Go high-performance compiler. Drone is not only very convenient to deploy, but more importantly, its stable operation will only occupy less than 20MB of memory on your server.

Deploying

docker-compose -f ./Drone/docker-compose.yaml up -d

Example

In addition, in order for Drone to coordinate with our own Gitea and tell it what to do after the code is submitted, we also need a YAML to describe its "work items".

github：https://github.com/otokaze/yourip

---
kind: pipeline
type: docker
name: default

platform:
  os: linux
  arch: amd64

steps:
- name: linter
  image: alpine/git
  commands:
  - change=$(git diff origin/master $DRONE_COMMIT ./CHANGELOG.md 2> /dev/null) && code=0 || code=$?
  - if [ ! $code -eq 0 ]; then echo 'CHANGELOG.md not fount.'; exit $code; fi
  - if [ -z "$change" ]; then echo 'CHANGELOG.md no change.'; exit 1; fi

- name: builder
  image: golang:1.13.8
  environment:
    GOOS: linux
    GOARCH: amd64
    CGO_ENABLED: 0
  commands:
  - go build -o yourip
  - go test

- name: tagger
  image: alpine
  commands:
  - tags=$(grep -E -o  v[0-9]+\.[0-9]+\.[0-9]+ CHANGELOG.md | head -1 | sed s/v/latest,/g)
  - if [ -z $tags ]; then echo 'No version found in CHANGELOG.md'; exit 1; else echo $tags > .tags; fi
  when:
    event:
    - push

- name: pushing
  image: plugins/docker
  settings:
    username:
      from_secret: DOCKER_REGISTRY_USERNAME
    password:
      from_secret: DOCKER_REGISTRY_PASSWORD
    repo: registry.otokaze.cn/yourip
    registry: registry.otokaze.cn
  when:
    event:
    - push

- name: deploying
  image: curlimages/curl
  environment:
    DEPLOY_API: https://swarm.otokaze.cn/api/services/yourip/redeploy
    TOKEN:
      from_secret: DOCKER_SWARMPIT_TOKEN
  commands:
  - code=$(curl -XPOST -s -w %{http_code} "$DEPLOY_API?tag=latest" -H 'Content-Type:application/json' -H "authorization:$TOKEN")
  - if [[ $code == "" || $code -lt 200 ]]; then echo "redeploy failed. HTTP_CODE=${code}"; exit 1; fi
  when:
    event:
    - push

trigger:
  branch:
  - master
  event:
  - pull_request
  - push
...

Swarmpit

Finally, I also need a container orchestration engine to manage my services, achieve smooth service upgrades, horizontal expansion, rollback release, etc.

Regarding the container orchestration engine, swarm is actually not a mainstream choice, but it is only used in a small range and the business volume is not large. I don’t need so many complicated functions and features of K8S, so Docker own Swarm became my best choice because it was simple enough and very easy to use.

Deploying

docker stack deploy -c ./Swarmpit/docker-compose.yml swarmpit