Upgrade Mattermost with minimum unavailability

upgrade-mattermost.sh

#!/bin/bash

SERVICE_NAME="mattermostdocker_app" # Change this with the service name you're using for the Mattermost service
SHORT_SERVICE_NAME="app"
VERBOSE_SERVICE_NAME="Mattermost"
DIRECTORY="/root/projects/mattermost-docker" # Change this with the path of your mattermost-docker project directory

PREVIOUS_CONTAINER=$(docker ps --format "table {{.ID}}  {{.Names}}  {{.CreatedAt}}" --filter "name=$SERVICE_NAME" | grep -v "ID" | awk -F  "  " '{print $1}')

cd $DIRECTORY

# Backup your docker-compose.yml in case
cp docker-compose.yml docker-compose.yml.old

git stash
git pull

if [ "$?" != "0" ]; then
  echo "The repository couldn't be pulled. Please check manually"
  exit 1
fi

git stash pop

if [ "$?" != "0" ]; then
  echo "The repository needs a merge, the update must be done manually."
  exit 1
fi

docker-compose build
docker-compose up -d --scale $SHORT_SERVICE_NAME=2 --no-recreate

SHOULD_CONTINUE="false"

echo "Waiting 10 seconds to ensure $VERBOSE_SERVICE_NAME is started."
sleep 10

for i in 2 3 4 5 6 7; do
  STATUS=$(docker ps --format "table {{.Status}}" --filter "name=${SERVICE_NAME}" | grep -v STATUS | head -n 1)

  if [[ "$STATUS" != *"Up"* ]] && [[ "$STATUS" != *"healthy"* ]]; then
    echo "Retry $i: service $VERBOSE_SERVICE_NAME not up yet, waiting another 10 seconds"
    sleep 10
  else
    SHOULD_CONTINUE="true"
    echo "Service $VERBOSE_SERVICE_NAME up after $(expr $i \* 10) seconds"
    break;
  fi
done

if [ "$SHOULD_CONTINUE" == "true" ]; then
  docker rm -f $PREVIOUS_CONTAINER
  docker-compose up -d --scale $SHORT_SERVICE_NAME=1 --no-recreate

  echo "Migration done!"

  echo "You can verify if all is ok by doing \`cd ${DIRECTORY} && docker-compose logs -f ${SHORT_SERVICE_NAME}\`"

  exit 0
fi

echo "Migration failed!"
exit 1