How can I open 8080 port on GCP

[Hikke]

Hello everyone,

I'm a new learner for GCP. 

I want to open the 8080 port on my Ubuntu VM, so I have searched lots of articles, videos and documents.

Many people give the solution that is setting the firewall rule.

I created the new rule with tcp:8080 for all instance, then I used `telnet` command on my local windows computer to test my GCP 8080 port.

It's like the link: how-to-open-a-specific-port-such-as-9090-in-google-compute-engine 

However, it failed.

Did I do something wrong?

- 2021/9/4 update 

I have found the problem.

It's not the port opening problem.

I have tried change apache port to 8080, then runs.

It works.

Therefore, the reason is my websocket server doesn't run successfully on 8080.

It's another problem...