63 lines
3.5 KiB
Markdown
63 lines
3.5 KiB
Markdown
# Canary Deployments **(PREMIUM)**
|
|
|
|
> [Introduced](https://gitlab.com/gitlab-org/gitlab/issues/1659) in [GitLab Premium](https://about.gitlab.com/pricing/) 9.1.
|
|
|
|
A popular [Continuous Deployment](https://en.wikipedia.org/wiki/Continuous_deployment)
|
|
strategy, where a small portion of the fleet is updated to the new version of
|
|
your application.
|
|
|
|
## Overview
|
|
|
|
When embracing [Continuous Delivery](https://about.gitlab.com/blog/2016/08/05/continuous-integration-delivery-and-deployment-with-gitlab/), a company needs to decide what
|
|
type of deployment strategy to use. One of the most popular strategies is canary
|
|
deployments, where a small portion of the fleet is updated to the new version
|
|
first. This subset, the canaries, then serve as the proverbial
|
|
[canary in the coal mine](https://en.wiktionary.org/wiki/canary_in_a_coal_mine).
|
|
|
|
If there is a problem with the new version of the application, only a small
|
|
percentage of users are affected and the change can either be fixed or quickly
|
|
reverted.
|
|
|
|
Leveraging [Kubernetes' Canary deployments](https://kubernetes.io/docs/concepts/cluster-administration/manage-deployment/#canary-deployments), visualize your canary
|
|
deployments right inside the [Deploy Board](deploy_boards.md), without the need to leave GitLab.
|
|
|
|
## Use cases
|
|
|
|
Canary deployments can be used when you want to ship features to only a portion of
|
|
your pods fleet and watch their behavior as a percentage of your user base
|
|
visits the temporarily deployed feature. If all works well, you can deploy the
|
|
feature to production knowing that it won't cause any problems.
|
|
|
|
Canary deployments are also especially useful for backend refactors, performance
|
|
improvements, or other changes where the user interface doesn't change, but you
|
|
want to make sure the performance stays the same, or improves. Developers need
|
|
to be careful when using canaries with user-facing changes, because by default,
|
|
requests from the same user will be randomly distributed between canary and
|
|
non-canary pods, which could result in confusion or even errors. If needed, you
|
|
may want to consider [setting `service.spec.sessionAffinity` to `ClientIP` in
|
|
your Kubernetes service definitions](https://kubernetes.io/docs/concepts/services-networking/service/#virtual-ips-and-service-proxies), but that is beyond the scope of
|
|
this document.
|
|
|
|
## Enabling Canary Deployments
|
|
|
|
Canary deployments require that you properly configure Deploy Boards:
|
|
|
|
1. Follow the steps to [enable Deploy Boards](deploy_boards.md#enabling-deploy-boards).
|
|
1. To track canary deployments you need to label your Kubernetes deployments and
|
|
pods with `track: canary`. To get started quickly, you can use the [Auto Deploy](../../topics/autodevops/index.md#auto-deploy)
|
|
template for canary deployments that GitLab provides.
|
|
|
|
Depending on the deploy, the label should be either `stable` or `canary`.
|
|
Usually, `stable` and blank or missing label means the same thing, and `canary`
|
|
or any other track means canary/temporary.
|
|
This allows GitLab to discover whether deployment is stable or canary (temporary).
|
|
|
|
Once all of the above are set up and the pipeline has run at least once,
|
|
navigate to the environments page under **Pipelines > Environments**.
|
|
As the pipeline executes Deploy Boards will clearly mark canary pods, enabling
|
|
quick and easy insight into the status of each environment and deployment.
|
|
|
|
Canary deployments are marked with a yellow dot in the Deploy Board so that you
|
|
can easily notice them.
|
|
|
|
|