report-changed-services

#!/usr/bin/env bash
# this depends on bash >= 4 as it uses associative arrays to handle
# lists of filenames that may contain spaces

set -e

USAGE='report-changed-services'
DESCRIPTION='
  Deploy helper to figure out what services were changed in a merge
  commit. Long term it would be better to use something like bazel,
  but this is good enough for now.

  This does not figure out when docker image base layers have changed,
  it only looks at the files in our monorepo to guess at which services
  have changes.

  We first get a list of all files changed in the merge commit or the
  branch being tested.

  Then, we run a list of checks for each service to see if that service
  has any patterns that match the file list in order to determine if the
  service needs to be deployed.

  Dependencies: requires git to be installed, requires bash >= 4'

function usage() {
	echo "$USAGE" "$DESCRIPTION" >&2
}

type git >/dev/null 2>&1 || {
	echo >&2 "Error: git must be installed. Aborting."
	usage
	exit 1
}
[ $# -eq 0 ] || {
	usage
	exit 1
}

if [ "${BASH_VERSINFO:-0}" -lt 4 ]; then
  echo "This version of bash does not support associative arrays, cannot run"
  usage
  exit 1
fi

CURRENT_BRANCH=$(git branch | grep \* | cut -d ' ' -f2)
echo "Current branch is ${CURRENT_BRANCH}"
CURRENT_REV=$(git rev-parse HEAD)

declare -A changed_files
if [[ "$CURRENT_BRANCH" == "master" ]]; then
  # If we are on master, calculate the changes in the merge commit.
  for filename in $(git diff --name-only HEAD^! 2>/dev/null); do
    changed_files["$filename"]=$filename
  done
else
  # If we are not on master, calculate the differences on this branch that are not yet in master
  for filename in $(git diff origin/master... --name-only 2>/dev/null); do
   changed_files["$filename"]=$filename
  done
fi

CHANGE_COUNT=${#changed_files[@]}

if [ "$CHANGE_COUNT" -eq 0 ]; then
  echo 'Did not detect any changed files'
else
  echo "Found $CHANGE_COUNT changed files"
  printf " * %s\n" "${changed_files[@]}"
fi

# in order to minimize gratuitous rebuilds and publishing container
# revisions with no meaningful changes, we use the current shipped container
# when a service hasn't changed. The origin/master revision will be the tag
# for the currently shipped version of any service.
export DEPLOY_GATEKEEPER=false
export GATEKEEPER_REV=latest
export DEPLOY_WEBUI=false
export WEBUI_REV=latest
export DEPLOY_KEYCLOAK=false
export KEYCLOAK_REV=latest
export DEPLOY_WORKER=false
export WORKER_REV=latest
export DEPLOY_HAVENAPI=false
export HAVENAPI_REV=latest
export DEPLOY_FLYWAY=false
export FLYWAY_REV=latest
export DEPLOY_FAKTORY=false
export FAKTORY_REV=latest

for filename in "${changed_files[@]}"; do
  case $filename in
    gatekeeper/*)
      DEPLOY_GATEKEEPER=true
      GATEKEEPER_REV=${CURRENT_REV}
      ;;
    webui/*)
      DEPLOY_WEBUI=true
      WEBUI_REV=${CURRENT_REV}
      ;;
    keycloak/*)
      DEPLOY_KEYCLOAK=true
      KEYCLOAK_REV=${CURRENT_REV}
      ;;
    keycloak-service-providers/*)
      DEPLOY_KEYCLOAK=true
      KEYCLOAK_REV=${CURRENT_REV}
      ;;
    worker/*)
      DEPLOY_WORKER=true
      WORKER_REV=${CURRENT_REV}
      ;;
    havenapi/*)
      DEPLOY_HAVENAPI=true
      HAVENAPI_REV=${CURRENT_REV}
      ;;
    flyway/*)
      DEPLOY_FLYWAY=true
      FLYWAY_REV=${CURRENT_REV}
      ;;
    faktory/*)
      DEPLOY_FAKTORY=true
      FAKTORY_REV=${CURRENT_REV}
      ;;
    *)
      echo "$filename did not trigger a service deploy"
    ;;
  esac
done

printf "\n"
echo "***********************************"
echo "* Services that need deployment   *"
echo "***********************************"
printf "\n"

echo "DEPLOY_GATEKEEPER=${DEPLOY_GATEKEEPER}"
echo "DEPLOY_WEBUI=${DEPLOY_WEBUI}"
echo "DEPLOY_KEYCLOAK=${DEPLOY_KEYCLOAK}"
echo "DEPLOY_WORKER=${DEPLOY_WORKER}"
echo "DEPLOY_HAVENAPI=${DEPLOY_HAVENAPI}"
echo "DEPLOY_FLYWAY=${DEPLOY_FLYWAY}"
echo "DEPLOY_FAKTORY=${DEPLOY_FAKTORY}"