In my current work setup, we have a lot of Kubernetes deployments. Most of them are Spring Boot applications, involving application.properties file. These properties files are loaded via ConfigMaps. Since the company is in early stages of application development, these config maps are changing frequently. Up until now, we have been performing manual rollout restart of deployments whose config has changed.
Pretty soon it became obviously that our manual process is not going to scale well, and we needed to do something about it. That’s when we found this extremely wonderful project, Reloader.
Installing Reloader is rather very simple. There are multiple ways to do it. I went with helm chart way. Mostly because upgrading packages are lot easier using helm. This is what I did to install reloader in our EKS and GKE clusters:
- add helm repo:
helm repo add stakater https://stakater.github.io/stakater-charts helm repo update - create custom
values.yamlfile for the helm installation:cat <<EOF | tee ~/reloader-values.yaml reloader: autoReloadAll: true EOF - install reloader:
helm install reloader stakater/reloader -n reloader \ --create-namespace -f ~/reloader-values.yaml
The values.yaml file can be found here. Most of the settings are self-explanatory. For us, the option autoReloadAll made more sense. This option basically starts reloader with argument --auto-reload-all.
Reloader, by default, will not watch for ConfigMaps/Secret changes, and we need to add extra annotation (like reloader.stakater.com/auto, etc.) to our deployments / daemonset / statefulset. But, when we use --auto-reload-all argument, all resources that do not have the auto annotation reloader.stakater.com/auto: "false", will be reloaded automatically when their ConfigMaps or Secrets are updated.
This worked out so well for us that we sent it to production within 2 days of testing in development environments.
I don’t think necessity is the mother of invention. Invention, in my opinion, arises directly from idleness, possibly also from laziness - to save oneself trouble.
- Agatha Christie
Well, How about that??
Until next time!!
