We were basing our CD on:
- Generating images with semantic version tagging
- Swarmpit auto-redeploy feature
But, it is expensive due Swarmpit checks DockerHub each minute for each image.
So, we want to do the same work attending Docker Hub web-hooks and, depending on the updated image and running services, take the right action:
sequenceDiagram
participant GitHub
participant Jenkins
participant DockerHub
participant WebHookHandler
participant Swarmpit
participant DockerService
GitHub->>Jenkins: pr/merge/tag
Jenkins->>DockerHub: Push image
DockerHub->>WebHookHandler: POST Hook
activate WebHookHandler
WebHookHandler->>Swarmpit: GET services
Swarmpit->>DockerService: get services
Swarmpit-->>WebHookHandler: services list
Note over WebHookHandler: Identify running services affected by the pushed image
loop Every {{affected service}}
WebHookHandler->>Swarmpit: POST services/{{affected service}}/redeploy
Swarmpit->>DockerService: redeploy
end
deactivate WebHookHandler
Then, as a next step, we could support a complete validation and update of obsolete services:
sequenceDiagram
participant User
participant WebHookHandler
participant Swarmpit
participant DockerHub
participant DockerService
User->>WebHookHandler: POST SmartRedeploy
activate WebHookHandler
WebHookHandler->>Swarmpit: GET services
Swarmpit->>DockerService: get services
Swarmpit-->>WebHookHandler: services list
loop Every {{service}}
WebHookHandler->>DockerHub: GET service digest
alt running digest != published digest
WebHookHandler->>Swarmpit: POST services/{{affected service}}/redeploy
Swarmpit->>DockerService: redeploy
end
end
deactivate WebHookHandler
For the moment, for simplicity, we will base it on Swarmpit API, but in the future, we could work directly against docker daemon.
When a commit is merged into the main branch or when a commit is pushed to the TEST branch, an image with the label TEST is generated. This image is used in our testing environment (related to Doppler's INT and QA environments).
When we create a branch with the format v#.#.# CI creates the following images:
v#v#.#v#.#.#v#.#.#_{commitId}
In the Production environment, we use the image v1.
See more information about these topics in
The source of truth related to the build process is Dockerfile. It basically runs docker build, so, you can reproduce CI build process running docker build ..
If you prefer to run these commands without docker, you can read Dockerfile and follow the steps manually.