eversc/k8s-master-upgrader repository overview

⁠k8s-master-upgrader

This is a script to upgrade a GKE master if a new version is available.

You can find the alpine-based Docker image here⁠.

To get the latest version available in a specific zone, it issues the following command:

gcloud container get-server-config \
  --zone $GCP_ZONE\
  --project $GCP_PROJECT\
  --format="json" | jq -r '.validMasterVersions[0]'

note: this does, therefore, require that Google return the latest validMasterVersions as the first element.

⁠Config

An example config:

CLUSTER_NAME=my-cluster
GCP_PROJECT=my-project
GCP_SA_ACCOUNT=k8s-master-upgrader@my-project.iam.gserviceaccount.com
GCP_ZONE=europe-west2-a
SLACK_WEBHOOK_URL=https://hooks.slack.com/services/**change_me**/**change_me**/**change_me**

The key.json for the GCP Service Account used in gcloud calls needs to be placed at the path /home/gcloud/key.json

⁠Env Vars

If an upgrade is performed, and you have SLACK_WEBHOOK_URL defined, the script will post a message to the Slack URL you've specified, with a message like:

k8s master of cluster: `my-cluster` upgraded from version `1.12.5-gke.10`
to `1.12.5-gke.5`.