Make the validation of the webapp container a bit more useful

This is almost a liveness probe 🔥

webapp/Makefile

@@ -14,7 +14,7 @@ run: depends monkeys.txt
 	./scripts/ruby bundle exec puma
 
 check-container: container
-	docker run --rm $(IMAGE_NAME):latest bundle exec puma --version
+	IMAGE_NAME=$(IMAGE_NAME) ./scripts/container-check
 
 container: depends Dockerfile monkeys.txt
 	docker build -t $(IMAGE_NAME) .

webapp/scripts/container-check

@@ -0,0 +1,35 @@
+#!/usr/bin/env bash
+
+NAME=codevalet-webapp-container-check
+PORT=9292
+URL=http://127.0.0.1:${PORT}/
+
+function terminate {
+  echo ">> Terminating ${NAME}"
+  docker stop ${NAME}
+  docker rm ${NAME}
+}
+
+trap terminate EXIT
+
+docker run --detach -p ${PORT}:${PORT} \
+  --name ${NAME} \
+  ${IMAGE_NAME}:latest \
+
+for i in $(seq 1 10); do
+  echo ">> Attempt #${i} to reach ${URL}"
+  curl -sI ${URL} 2>&1 > /dev/null
+  if [ $? -ne 0 ]; then
+    sleep 1
+  else
+    echo '----> :) The app returned a 200'
+    exit 0
+  fi;
+  sleep 1
+done;
+
+echo "----> :( Failed to reach the container"
+
+docker ps
+# If we get to here without having bailed out, something is wrong
+exit 1