Add nginx health check

docker/Dockerfile

@@ -20,11 +20,23 @@ RUN npm run production
 
 FROM nginxinc/nginx-unprivileged:1.14-alpine AS nginx
 
+USER root
+
+RUN apk add --update --no-cache \
+        curl
+
 COPY ./docker/nginx.conf /etc/nginx/nginx.conf
 COPY ./docker/server.conf /etc/nginx/conf.d/default.conf
 
 COPY --from=resources /home/node/app/public /var/www/html/public
 
+USER nginx
+
+HEALTHCHECK --start-period=15s --interval=30s --timeout=5s \
+    CMD curl -f http://localhost:8081/health || exit 1
+
+EXPOSE 8080 8081
+
 ########################################
 
 FROM php:7.3-fpm-alpine AS php-fpm

docker/server.conf

@@ -19,3 +19,18 @@ server {
         fastcgi_param PATH_INFO $fastcgi_path_info;
     }
 }
+
+server {
+    server_name localhost;
+    listen 8081 default_server;
+    listen [::]:8081 default_server;
+
+    location / {
+        return 200 "Port 8081\n";
+    }
+
+    location /health {
+        access_log off;
+        return 200 "healthy\n";
+    }
+}