Nginx / Node.JS-仅在节点服务器完全启动后启动Nginx

Question

How can I configure nginx systemd service to start only after a node.js server is fully started.

I have an ubuntu server with 1 CPU and 5 systemd services:

1. nginx_dashboard.service
2. 4 X dashboard_customer@.service

all services run at startup and all are running docker containers. Only the nginx container is exposed outside and it is the one that links to the 4 node applications.

The problem is that because of the 1 CPU and all services are starting together, it takes a few seconds for the node applications to start (10-13 seconds) while the much lighter nginx starts immediately. I tried adding Requires and After to the nginx service, but it doesn't help since the node services are running, but the app itself inside the containers takes time to load.

In case the nginx is down, my content delivery system (in this case - CloudFlare), knows to present a temp page. But because of this delay, the nginx is up and I have a few seconds of downtime to my dashboard.

The question is if I can prevent this delay and start nginx only after the node.js application is fully up, not just the docker container.

Answer 1

You can create a /healthz route for checking if the app is ready. IN your nginx service, you can recursively check if the app is ready ( /healthz returns http status code 200) and only start once it's ready.