Improve upgrade script

Pull containers up front
Take backup snapshot

upgrade-old-new.sh

@@ -15,33 +15,43 @@ NEW=$4
 
 cd "$APP_PATH"
 
-# 1. stop db container
+# Pull necessary containers
+echo "Pulling containers for later steps"
+docker pull tianon/postgres-upgrade:"$OLD"-to-"$NEW"
+docker pull napstr/poggres:"$NEW"
+
+# Stop db container
 echo "Stopping DB container $CONTAINER_NAME"
 docker stop "$CONTAINER_NAME"
 
-# 2. Create new directory
-DATA_PATH="$APP_PATH/postgres-data/$NEW/data"
-echo "Creating $DATA_PATH"
-mkdir -p "$DATA_PATH"
+# Make backup of the directory
+DATA_PATH="$APP_PATH/postgres-data/"
+echo "Creating a backup"
+tar --use-compress-program="pigz --best --recursive" -cvf postgres-data.tar.gz "$DATA_PATH"
+
+# Create new directory
+NEW_DATA_PATH="$APP_PATH/postgres-data/$NEW/data"
+echo "Creating $NEW_DATA_PATH"
+mkdir -p "$NEW_DATA_PATH"
 
-# 3. run upgrade container
+# Run upgrade container
 echo "Running upgrade container"
 docker run --rm \
   -v "$APP_PATH"/postgres-data:/var/lib/postgresql \
   tianon/postgres-upgrade:"$OLD"-to-"$NEW" \
   --link
 
-# 4. pull and run latest database container
+# Run latest database container
 UPDATE_SCRIPT="$APP_PATH/docker-update.sh"
 echo "Updating containers $UPDATE_SCRIPT"
 sh "$UPDATE_SCRIPT"
 
-# 5. Fix pg_hba
+# Fix pg_hba
 echo "Fixing pg_hba"
 echo "host all all all md5" >> "$APP_PATH"/postgres-data/"$NEW"/data/pg_hba.conf
 docker restart "$CONTAINER_NAME"
 
-# 6. generate optimizer statistics
+# Generate optimizer statistics
 echo "Waiting a bit"
 sleep 10
 echo "Generating optimizer statistics"