OpenShift

This page covers OpenShift-specific setup: installing Fission, running the Logger as a privileged container, and enabling Prometheus metrics.

Installing Fission

See Fission installation to learn how to install Fission.

Run Logger as privileged container

Logger pods must run as a privileged container because Fission mounts a hostPath volume into FluentBit to read container log files and persist data.

The persistence is for FluentBit’s tail plugin to read/write its own sqlite database. Fission itself doesn’t persist anything.

Optionally a database file can be used so the plugin can have a history of tracked files and a state of offsets, this is very useful to resume a state if the service is restarted.

Once the logger restarts, it ensures no duplicate logs are sent to the log database.

You may need to add privileged permission to the logger’s service account fission-fluentbit.

oc adm policy add-scc-to-user privileged -z fission-fluentbit -n fission

• Reference: https://github.com/fluent/fluentd-kubernetes-daemonset#running-on-openshift

Prometheus

• Follow this guide to deploy Prometheus to OpenShift cluster.

• Get Prometheus server URL by following Accessing Prometheus, Alertmanager, and Grafana.

For example, if we have https://prometheus-k8s-openshift-monitoring.apps._url_.openshift.com as Prometheus server URL, encode following config with base64

$ base64 <<EOF
canary:
  enabled: true
  prometheusSvc: "https://prometheus-k8s-openshift-monitoring.apps._url_.openshift.com"
EOF

Patch configmap feature-config in fission namespace with output from previous step

$ kubectl -n fission patch configmap feature-config \
    -p '{"data":{"config.yaml":"Y2FuYXJ5OgogIGVuYWJsZWQ6IHRydWUKICBwcm9tZXRoZXVzU3ZjOiAiaHR0cHM6Ly9wcm9tZXRoZXVzLWs4cy1vcGVuc2hpZnQtbW9uaXRvcmluZy5hcHBzLl91cmxfLm9wZW5zaGlmdC5jb20iCg"}}'

Restart the canaryconfig pod so it reloads the updated config.

$ kubectl -n fission delete pod -l svc=canaryconfig