Script that can be used to remove outdated apprevisions

rancher-clean-apprevisions.sh

#! /bin/bash

# The scripts needs to run agains the Kubernetes cluster where rancher is installed, make sure to setup your context/credentials for kubectl
# If you run it with no arguments, it will ask you to confirm before looking at each cluster, and before removing app revisions in a given rancher project
# Alternatively run with "--force-yes" and will clean without asking

set -eu

# process arguments. See https://stackoverflow.com/a/24597113/1836935
forceYes=false
for ((i=1;i<=$#;i++));
do
    if [ ${!i} = "--force-yes" ]
    then forceYes=true;

    # In case we ever add a parameter that has an argument like "-s foo"
    # elif [ ${!i} = "-s" ]
    # then ((i++))
    #     var1=${!i};

    fi
done;

# get list of clusters
clusters=$(kubectl get cluster --no-headers=true | awk '{print $1}')
for cluster in $clusters
do
    echo "Processing cluster $cluster"

    # ask for explicit confirmation before looking at cluster
    if [[ "$forceYes" == "false" ]]; then
      read -p "Do you want to proceed? only yes will be accepted"$'\n' answer
      if [[ ! $answer =~ ^yes$ ]]; then
          continue
      fi
    fi

    # get list of all projects in the cluster
    # NOTE: can get all prokects in any cluster using --all-namespaces
    #       however this way the user can explicitly run cleanup on specific clusters

    # projects=$(kubectl get project --no-headers=true --all-namespaces | awk '{print $2}')
    projects=$(kubectl get project --no-headers=true -n $cluster | awk '{print $1}')
    for project in $projects
    do

        echo "Processing project $cluster:$project"
        appCount=$(kubectl -n $project get app --ignore-not-found --no-headers=true | wc -l)
        if [[ ! $appCount > 0 ]]; then
            echo "no apps in the project"
            continue
        fi

        # get the total app revision count
        apprevisionCount=$(kubectl -n $project get apprevision --no-headers=true | wc -l)

        # get the current app revision names
        # To do so, get the field ".spec.appRevisionName" of every installed app (where the field exists)
        # We get them in a "|" delimited string so its easier to use a parameter for awk (with a negative regex match we can then get all non-current app revisions)
        currentAppRevisions=$(kubectl -n $project get app -o jsonpath='{range .items[?(@.spec.appRevisionName)]}{.spec.appRevisionName}{"|"}{end}{"\n"}')
        currentAppRevisions=${currentAppRevisions:0:-1}

        # get the count of apprevisions that are neither of the current app revisions (ie, the count of revisions to delete)
        oldAppRevisionsCount=$(kubectl -n $project get apprevision --no-headers=true | awk -v regex=$currentAppRevisions '$0 !~ regex {print $1}' | wc -l)

        # Let the user review the numbers of apps and apprevisions and confirm if they want to proceed
        echo "Project $cluster:$project:"
        echo "  Total apps=$appCount"
        echo "  Total revisions=$apprevisionCount"
        echo "  Revisions to remove=$oldAppRevisionsCount"

        if [[ ! $oldAppRevisionsCount > 0 ]]; then
            echo "no outdated apprevisions to remove in the project"
            continue
        fi

        # ask for explicit confirmation before cleaning revisions for this project
        if [[ "$forceYes" == "false" ]]; then
          read -p "Do you want to proceed? only yes will be accepted"$'\n' answer
          if [[ ! $answer =~ ^yes$ ]]; then
              continue
          fi
        fi

        # If confirmed, delete all non-current apprevisions
        kubectl -n $project get apprevision --no-headers=true | awk -v regex=$currentAppRevisions '$0 !~ regex {print $1}' | xargs kubectl -n $project delete apprevision
    done

done