Running Localstack SQS using Docker Compose; While starting container giving error '/tmp/localstack': Device or resource busy

Question

I'm trying to run sqs with localstack using docker compose to execute application tests but localstack container not starting.

  localstack:
    image: localstack/localstack
    container_name: localstack_main
    ports:
      - "4566:4566"
      - "4571:4571"
      - "8055:8080"
    environment:
      - SERVICES=sqs
      - DEBUG=1
      - DATA_DIR=/tmp/localstack/data
    volumes:
      - "./localstack_data:/tmp/localstack" # Mounts the local directory to the container
      - "/var/run/docker.sock:/var/run/docker.sock" # Mounts the docker socket
#    tmpfs:
#      - /tmp/localstack:exec,mode=777

Getting error in container logs

LocalStack supervisor: starting
LocalStack supervisor: localstack process (PID 15) starting
ERROR: 'rm -rf "/tmp/localstack"': exit code 1; output: b"rm: cannot remove '/tmp/localstack': Device or resource busy\n"
Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "/opt/code/localstack/localstack/runtime/main.py", line 28, in <module>
    main()
  File "/opt/code/localstack/localstack/runtime/main.py", line 20, in main
    infra.start_infra(asynchronous=False)
  File "/opt/code/localstack/localstack/services/infra.py", line 220, in start_infra
    files.rm_rf(config.dirs.tmp)
  File "/opt/code/localstack/localstack/utils/files.py", line 214, in rm_rf
    shutil.rmtree(path)
  File "/usr/local/lib/python3.11/shutil.py", line 763, in rmtree
    onerror(os.rmdir, path, sys.exc_info())
  File "/usr/local/lib/python3.11/shutil.py", line 761, in rmtree
    os.rmdir(path, dir_fd=dir_fd)
OSError: [Errno 16] Device or resource busy: '/tmp/localstack'
LocalStack supervisor: localstack process (PID 15) returned with exit code 1
LocalStack supervisor: exiting

How to fix ?

Answer 1

The error is coming from the localstack bootup code, which exists on /opt/code/localstack/localstack, which attempts to clear the configured temp folder on startup.

This process will handle a permission error, but when you have mounted a file system, you receive a different error - Device busy, which causes the code to not start up, as that exception is not caught by the cleanup code.

What it's implying, though, is that the temporary folder is really not a place to put your code/data. It indicates also that the entire folder will be purged every run, which sounds like a bad thing?

The 'basic' openstack docker-compose indicates the following:

- "${LOCALSTACK_VOLUME_DIR:-./volume}:/var/lib/localstack"

So, it seems that using this pattern - mapping ./localstack_data to /var/lib/localstack is the right thing to do in this case:

  localstack:
    image: localstack/localstack
    container_name: localstack_main
    ports:
      - "4566:4566"
      - "4571:4571"
      - "8055:8080"
    environment:
      - SERVICES=sqs
      - DEBUG=1
      - PERSISTENCE=1
    volumes:
      - "./localstack_data:/var/lib/localstack" # Mounts the local directory to the container
      - "/var/run/docker.sock:/var/run/docker.sock" # Mounts the docker socket

Note - I have removed DATA_DIR, and added PERSISTENCE based on the localstack documentation, which states:

DATA_DIR implicitly points to /var/lib/localstack/state if persistence is enabled. Use PERSISTENCE=1 to enable persistence. If DATA_DIR is set, its value is ignored, a warning is logged and PERSISTENCE is set to 1.