Create similar alertmanager configurations across all instances of running alertmanagers
Today the alertmanager consists of three files:
- https://gitlab.com/gitlab-cookbooks/gitlab-alertmanager/blob/master/templates/default/alertmanager.yml.erb
- https://gitlab.com/gitlab-cookbooks/gitlab-alertmanager/tree/master/files/default/alertmanager/templates
The alertmanager.yml.erb is put together by chef and contains secret data that we store inside of GKMS. We need to determine a way to recreate this workflow such that we can make the same modification to one set of files and these are then pulled in by both chef, and our desired mechanism for deploying the alertmanagers inside of Kubernetes.
Reference Doc: https://docs.google.com/document/d/1oJcWY4U2lmPwBvY8qQPlP7msPc7ioVUlo3ZKkCp-i1g/edit
Related Issue: https://gitlab.com/gitlab-com/gl-infra/infrastructure/issues/6927