= Fedora CoreOS Cincinnati SOP

Cincinnati is the update service/backend for Fedora CoreOS (FCOS) machines.
This SOP describes how to access and how to troubleshoot it.

== Contact Information

Owner::
  Fedora CoreOS Team
Contact::
  #fedora-coreos

== Details

Source::
  https://github.com/coreos/fedora-coreos-cincinnati
Playbook::
  https://pagure.io/fedora-infra/ansible/blob/main/f/playbooks/openshift-apps/coreos-cincinnati.yml
Location::
  OpenShift cluster (production): https://console-openshift-console.apps.ocp.fedoraproject.org/
Project::
  coreos-cincinnati:
  https://console-openshift-console.apps.ocp.fedoraproject.org/k8s/cluster/projects/coreos-cincinnati
Deployment::
  https://console-openshift-console.apps.ocp.fedoraproject.org/k8s/ns/coreos-cincinnati/deploymentconfigs/coreos-cincinnati
Containers::
  * `fcos-graph-builder` (GB - raw updates graph)
  * `fcos-policy-engine` (PE - frontend handling client requests)
Routes::
  * `coreos-updates-raw` (GB web service)
  * `coreos-updates-raw-status` (GB status and metrics)
  * `coreos-updates` (PE web service)
  * `coreos-updates-status` (PE status and metrics)

== Troubleshooting

Each FCOS Cincinnati service exposes live metrics in Prometheus format:

Graph-builder::
  https://status.raw-updates.coreos.fedoraproject.org/metrics
Policy-engine::
  https://status.updates.coreos.fedoraproject.org/metrics

== Upgrades

=== Build and deploy a new version

FCOS Cincinnati is built as container image directly from source,
referencing a pinned git commit.

In order to build and deploy a new version, you will first have to find the
relevant commit (i.e. the latest on the `main` branch) at
https://github.com/coreos/fedora-coreos-cincinnati .

Once you have identified the target commit, these are the steps to build
a new container image:

  * update the `fcos_cincinnati_git_sha` playbook variable in
    `roles/openshift-apps/coreos-cincinnati/vars/staging.yml`
  * update the `fcos_cincinnati_git_sha` playbook variable in
    `roles/openshift-apps/coreos-cincinnati/vars/production.yml`
  * commit and push the update to the `fedora-infra/ansible` repository
  * SSH to `batcave01.iad2.fedoraproject.org`
  * run `sudo rbac-playbook openshift-apps/coreos-cincinnati.yml` using
    your FAS password and your second-factor OTP
  * schedule a new build by running
    `sudo rbac-playbook -t build openshift-apps/coreos-cincinnati.yml`
  * Wait for the coreos-cincinnati-img:latest tag to be updated

== Things that could go wrong

=== Application build is stuck

Issues in the underlying OpenShift cluster may result in builds being
permanently stuck.

If a build does not complete within a reasonable amount of time (i.e. 15
minutes):

  * go to the build overview at https://console-openshift-console.apps.ocp.fedoraproject.org/k8s/ns/coreos-cincinnati/builds
  * click on the build
  * cancel it through the "Cancel Build" button
  * go back to the build overview page
  * schedule a new build through the "Start Build" button
