db:prepare is running in issues, therefore use single db commands depending on the state of the database. tested with fresh deployment and migrations

compose.yml

@@ -97,6 +97,7 @@ services:
       - loomio_files:/loomio/public/files
       - loomio_plugins:/loomio/plugins/docker
   db:
+    # loomio version upgrades and postgres version upgrade should not be performed at the same time.
     image: pgautoupgrade/pgautoupgrade:17-debian
     networks:
       - backend

entrypoint.sh

@@ -25,6 +25,7 @@ file_env "DEVISE_SECRET"
 file_env "SECRET_COOKIE_TOKEN"
 file_env "POSTGRES_PASSWORD"
 file_env "SMTP_PASSWORD"
+export DB_HOST="db"
 export DATABASE_URL="postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@db/${POSTGRES_DB}"
 
 if [ -n "$1" ]; then
@@ -36,8 +37,33 @@ else
 	if [ "$TASK" = "worker" ]; then
   		bundle exec sidekiq
 	else
+		sudo apt update -y && sudo apt install -y postgresql-client
 		bundle install
-		bundle exec rake db:prepare
+
+		# running this code instaed of db:prepare in docker_start.sh in loomio container
+		# as postgres container creates empty db, somehow db:prepare cannot cope.
+		# therefore we run db:setup or db:migrate individually
+		if PGPASSWORD=$(cat /run/secrets/db_password) psql -U "$POSTGRES_USER" -h "$DB_HOST" -lqt | cut -d \| -f 1 | grep -wq "$POSTGRES_DB"; then
+			echo "database '$POSTGRES_DB' exists."
+
+			# check if the database contains tables
+			TABLE_COUNT=$(PGPASSWORD=$(cat /run/secrets/db_password) psql -U "$POSTGRES_USER" -h "$DB_HOST" -d "$POSTGRES_DB" -t -c "SELECT count(*) FROM information_schema.tables WHERE table_schema = 'public';")
+
+			if [ "$TABLE_COUNT" -eq 0 ]; then
+				echo "Database '$POSTGRES_DB' is empty, running db:setup."
+				bundle exec rake db:setup
+				#bundle exec rake db:schema:load
+				#bundle exec rake db:migrate
+				#bundle exec rake db:seed
+			else
+				echo "database '$POSTGRES_DB' not empty, running migrations."
+				bundle exec rake db:migrate
+			fi
+		else
+			echo "database '$POSTGRES_DB' does not exist, running db:setup."
+			bundle exec rake db:setup
+		fi
+
 		bundle exec puma -C config/puma.rb
 	fi
 fi