Docker Expose Port 307

Expose Port 307 in Docker

docker run -p 307:307 your-image-name
		

This command maps container port 307 to the same port on the host machine.

Dockerfile Example

FROM node:18-alpine
WORKDIR /app
COPY . .
EXPOSE 307
CMD ["npm", "start"]
		

The EXPOSE instruction documents that the container listens on port 307.

EXPOSE vs Publish (-p)

• EXPOSE 307 documents the port inside the container.
• -p 307:307 makes the port accessible from the host.
• Exposed ports are not reachable unless published.

Docker Expose Port 307 Not Working

If Docker expose port 307 is not working, it is usually due to incorrect port publishing, an application not listening on the expected port, or a port conflict on the host machine.

Port 307 Already in Use

The error “port 307 already in use” means another process is already bound to that port on your host system.

# Find process using port 307
lsof -i :307

# OR use a different host port
docker run -p 8080:307 your-image-name
		

• Ensure your app is listening on port 307 inside the container
• Verify the port is published using -p
• Check firewall or network rules
• Avoid conflicts with existing services

Related Docker Expose Port Guides