谷歌云Ubuntu虚拟机中Docker BusyBox容器无法外部IP访问

Let’s break down why you’re hitting that "site unreachable" error and fix it step by step:

The Root Problem: BusyBox Doesn’t Run a Web Service by Default #

When you start a BusyBox container with just the sh command, it only spins up a shell session—there’s no web server listening on port 8080 (the container port you mapped to your host’s ports). That’s why your external URLs aren’t working.

Step 1: Confirm No Service is Listening in the Container #

First, verify there’s nothing running on port 8080 inside your containers. Run this for each container (swap bb1 with tt3 for the other one):

docker exec -it bb1 netstat -tulpn

If netstat isn’t available, use BusyBox’s built-in tool:

docker exec -it bb1 ss -tulpn

You’ll almost certainly see no entries for port 8080—proof no service is active there.

Step 2: Start a Simple Web Service in the Container #

BusyBox includes a tiny built-in web server called httpd. Let’s get it running:

1. Jump into the container shell:

   docker exec -it bb1 sh
   

2. Create a test HTML file so you have something to view:

   echo "<h1>Hello from BusyBox!</h1>" > /tmp/index.html
   

3. Launch the web server on port 8080, using /tmp as the web root:

   httpd -p 8080 -h /tmp
   

4. Exit the shell with Ctrl+D.

Repeat these steps for your tt3 container too.

Step 3: Test Locally First #

Before trying your external IP, test from your host machine to rule out port mapping issues:

• For bb1: curl http://localhost:32769
• For tt3: curl http://localhost:80
  If you see your test HTML content, the container service and port mapping are working correctly.

Step 4: Fix External Access Blockages #

If local access works but external access fails:

• Check your host firewall: Make sure tools like ufw (Ubuntu) or iptables allow incoming traffic on ports 80 and 32769.
• Check cloud security groups: If you’re using a cloud server (like Google Cloud), confirm your instance’s security group has rules permitting inbound traffic on those ports (allow your external IP specifically, or 0.0.0.0/0 for testing).

Pro Tip: Start the Web Service Automatically #

Avoid manually starting httpd every time by launching the container with the web server command directly:

docker run -d -p 80:8080 --name tt3 busybox httpd -p 8080 -h /tmp

This way, the web server boots up as soon as the container starts.

内容的提问来源于stack exchange，提问作者SHC