version: '2'
services:
  web:
    container_name: myapp
    build: .
    command: node app.js
    ports:
      - "9000:3000"

The root cause lies in how docker-compose identifies services versus how containers are named. In your docker-compose.yml, you've defined the service as web but assigned the container name as myapp. This creates confusion when trying to reference the service.

Instead of:

docker-compose run myapp /bin/bash

You should use:

docker-compose run web /bin/bash

OR

docker exec -it myapp /bin/bash

For interactive shell access:

# Using docker-compose service name
docker-compose exec web sh

# Using container name directly
docker exec -it myapp sh

Here's a better approach for your docker-compose.yml:

version: '3'
services:
  myapp:  # Use same name for service and container
    container_name: myapp
    build: .
    command: node app.js
    ports:
      - "9000:3000"
    stdin_open: true  # For interactive mode
    tty: true         # For terminal allocation

1. Verify services:

docker-compose ps

2. Check service names:

docker-compose config --services

3. If using custom container names, remember:

# docker-compose commands use SERVICE names
# docker commands use CONTAINER names

The error occurs because docker-compose run expects a service name (defined in docker-compose.yml) rather than the container name. In your case, you're trying to use myapp which is the container_name, while the actual service is named web in the YAML file.

For Docker Compose operations, you should always reference the service name from your YAML file:

docker-compose run web /bin/bash

If you specifically need to work with the container name (perhaps in scripts where you only have the container name), you can use regular docker commands:

docker exec -it myapp /bin/bash

Here's a full example showing both methods with a Node.js application:

version: '3.8'
services:
  web:
    container_name: myapp
    image: node:14
    working_dir: /app
    volumes:
      - ./:/app
    command: ["node", "server.js"]
    ports:
      - "9000:3000"

• Error: Cannot create container for service web - Usually indicates a port conflict
• Error: No such container - The container isn't running (use docker-compose up -d first)

1. Always keep service names in docker-compose.yml simple and meaningful
2. Use docker-compose ps to verify running services
3. For production, consider using docker-compose exec instead of run for existing containers