docs/doc/source/security/kubernetes/the-cert-manager-bootstrap-process.rst

Configure cert-manager at Bootstrap

Both nginx-ingress-controller and cert-manager are installed at bootstrap time with defaults appropriate to most use cases, but their configuration can be modified at bootstrap.

Nginx-ingress-controller and cert-manager are packaged as armada system applications.

Both system applications are uploaded and applied, by default, as part of the bootstrap phase of the installation. /usr/share/ansible/stx-ansible/playbooks/host_vars/bootstrap/default.yml contains the following definition:

...
applications:
  - /usr/local/share/applications/helm/nginx-ingress-controller-1.0-0.tgz:
  - /usr/local/share/applications/helm/cert-manager-1.0-0.tgz:
...

As with other parameters in default.yml, you can override this definition in $HOME/localhost.yml. In the case of the applications: parameter, do this to change the application helm overrides for an application.

The full general syntax for the applications: structure is:

applications:
  - /full/path/to/appOne-1.0-0.tgz:
      overrides:
        - chart: appOne-ChartOne
          namespace: kube-system
          values-path: /home/sysinv/appOne-ChartOne-overrides.yaml
        - chart: appOne-ChartTwo
          namespace: kube-system
          values-path: /home/sysinv/appOne-ChartTwo-overrides.yaml
  - /full/path/to/appTwo-1.0-0.tgz:
      overrides:
        - chart: appTwo-ChartOne
          namespace: kube-system
          values-path: /home/sysinv/appTwo-ChartOne-overrides.yaml

If you do override applications: in $HOME/localhost.yml, note the following:

• The applications: definition in localhost.yml replaces rather than augments the definition in default.yml.
• Semantically, nginx-ingress-controller and cert-manager are mandatory and must be in this order, otherwise bootstrap fails.

recommends that you copy applications: from default.yml and add in any required overrides.

At a high-level, the default configuration for the two mandatory applications is:

• nginx-ingress-controller
  • Runs as a DaemonSet only on masters/controllers.
  • Uses host networking, which means it can use any port numbers.
  • Does not change the nginx default ports of 80 and 443.
  • Has a default backend.
• cert-manager
  • Runs as a Deployment only on masters/controllers.
  • Runs with a podAntiAffinity rule to prevent multiple pods of deployment from running on the same node.
  • The deployment replicaCount is set to 1 for bootstrap.

Note

replicaCount can NOT be changed at bootstrap time. The second controller must be configured and unlocked before replicaCount can be set to 2.

The Helm Chart Values that you can override are described on the following web pages:

• Nginx-ingress-controller

  https://github.com/kubernetes/ingress-nginx/tree/controller-v0.41.2

• cert-manager

  https://github.com/jetstack/cert-manager/blob/release-0.15/deploy/charts/cert-manager/README.template.md