Checking and Resolving Port Conflicts When Running Docker with the “-network host” Option

If there is another service already running on port 8443, and you attempt to run a Docker container using the --network host option, the container will fail to start because it will try to bind to the same port, leading to a port conflict. Steps to Resolve Port Conflicts

1. Identify Services Using Ports Use tools like netstat or ss to check which services are currently listening on the host ports. For example:

# netstat -tuln | grep 8443

This command will show you if port 8443 is already in use and by which service.

1. Change Host Port If the port is already in use, consider changing the host port for the existing service or the Docker container. Since --network host does not allow port mapping, you would need to change the port of the existing service or avoid using --network host.

Alternative Approach: Use Bridge Network Mode Instead of using --network host, you can use the default bridge network mode and map the container ports to different host ports. This avoids port conflicts and allows you to specify which ports to expose.

1. Run Kasm Workspaces Container with Port Mapping

#   docker run -d --name kasm_workspaces --restart unless-stopped \
     -p 8444:8443 -p 443:443 -p 80:80 \
     kasmweb/workspaces:1.16.1

In this example, the container’s port 8443 is mapped to host port 8444, avoiding the conflict with the existing service on port 8443. Example: Checking and Resolving Port Conflicts

1. Check for Existing Services on Port 8443

# netstat -tuln | grep 8443

1. Run Container with Different Host Port

#   docker run -d --name kasm_workspaces --restart unless-stopped \
     -p 8444:8443 -p 443:443 -p 80:80 \
     kasmweb/workspaces:1.16.1

By following these steps, you can avoid port conflicts and ensure that your Docker container runs smoothly alongside other services on your host. If you have any further questions or need additional assistance, feel free to ask!