Add docker entrypoint script for enabling swapfile

Dockerfile

@@ -78,6 +78,7 @@ RUN mkdir -p tmp/pids
 
 COPY --link --chown=loot \
 	config.ru \
+	docker-entrypoint \
 	Gemfile* \
 	Rakefile ./
 
@@ -89,4 +90,6 @@ COPY --link --chown=loot --from=frontend build/public public/
 
 EXPOSE 3000
 
+USER root
+ENTRYPOINT ["/loot/docker-entrypoint"]
 CMD ["bundle", "exec", "puma"]

docker-entrypoint

@@ -0,0 +1,18 @@
+#!/bin/sh -e
+
+# This entrypoint script is customised for use with Alpine Linux and Fly.io
+
+# If the user is root
+if [ $(id -u) -eq 0 ]; then
+  # Set the swappiness level to 10
+  sysctl --write vm.swappiness=10
+
+	# Enable the swapfile
+  swapon /swapfile
+
+	# Switch to a non-root system user and re-execute the command
+  exec su --shell /bin/sh loot --command "$0 $*"
+fi
+
+# Execute the script args as a command
+$@

package.json

@@ -91,10 +91,6 @@
 		"deploy": "fly deploy --build-arg NODE_VERSION=$npm_package_engines_node --build-arg NPM_VERSION=$npm_package_engines_npm --build-arg RUBY_VERSION=$npm_package_engines_ruby",
 		"deploy:staging": "npm run deploy -- --app loottest",
 		"deploy:production": "npm run deploy -- --app lootprod",
-		"swap:configure": "fly ssh console --command 'sysctl --write vm.swappiness=10'",
-		"swap:on": "fly ssh console --command 'swapon /swapfile'",
-		"postdeploy:staging": "npm run swap:configure -- --app loottest && npm run swap:on -- --app loottest",
-		"postdeploy:production": "npm run swap:configure -- --app lootprod && npm run swap:on -- --app lootprod",
 		"swap:check": "fly ssh console --command 'free'"
   },
   "engines": {