Troubleshooting Cilium deployed with Argo CD

There have been reports from users hitting issues with Argo CD. This documentation page outlines some of the known issues and their solutions.

Argo CD deletes CustomResourceDefinitions

When deploying Cilium with Argo CD, some users have reported that Cilium-generated custom resources disappear, causing one or more of the following issues:

ciliumid not found (GitHub issue 17614)
Argo CD Out-of-sync issues for hubble-generate-certs (GitHub issue 14550)
Out-of-sync issues for Cilium using Argo CD (GitHub issue 18298)

Solution

To prevent these issues, declare resource exclusions in the Argo CD ConfigMap by following these instructions.

Here is an example snippet:

resource.exclusions: |
 - apiGroups:
     - cilium.io
   kinds:
     - CiliumIdentity
   clusters:
     - "*"

Also, it has been reported that the problem may affect all workloads you deploy with Argo CD in a cluster running Cilium, not just Cilium itself. If so, you will need the following exclusions in your Argo CD application definition to avoid getting “out of sync” when Hubble rotates its certificates.

ignoreDifferences:
  - group: ""
    kind: ConfigMap
    name: hubble-ca-cert
    jsonPointers:
    - /data/ca.crt
  - group: ""
    kind: Secret
    name: hubble-relay-client-certs
    jsonPointers:
    - /data/ca.crt
    - /data/tls.crt
    - /data/tls.key
  - group: ""
    kind: Secret
    name: hubble-server-certs
    jsonPointers:
    - /data/ca.crt
    - /data/tls.crt
    - /data/tls.key

Note

After applying the above configurations, for the settings to take effect, you will need to restart the Argo CD deployments.

Helm template with serviceMonitor enabled fails

Some users have reported that when they install Cilium using Argo CD and run helm template with serviceMonitor enabled, it fails. It fails because Argo CD CLI doesn’t pass the --api-versions flag to Helm upon deployment.

Solution

This pull request fixed this issue in Argo CD’s v2.3.0 release. Upgrade your Argo CD and check if helm template with serviceMonitor enabled still fails.

Note

When using helm template, it is highly recommended you set --kube-version and --api-versions with the values matching your target Kubernetes cluster. Helm charts such as Cilium’s often conditionally enable certain Kubernetes features based on their availability (beta vs stable) on the target cluster.

By specifying --api-versions=monitoring.coreos.com/v1 you should be able to pass validation with helm template.

If you have an issue with Argo CD that’s not outlined above, check this list of Argo CD related issues on GitHub. If you can’t find an issue that relates to yours, create one and/or seek help on Cilium Slack.