Docker Compose Error "TypeError: expected string or buffer" on docker:dind (ports)

Question

I'm triying to setup my containers with docker-compose in a docker container (docker:dind) to make the tests at gitlab ci.

From yesterday to today it has begin to fail on "docker-compose up" and i reduced the error to "ports" segment at service in docker-compose.yml. The simpliest configuration that fails is that:

version: '3':
services:
        ubuntu:
                image: ubuntu:latest
                ports:
                        - 80:80

I've tried without ports and it works.

The specific error is this:

ERROR: for ubuntu  expected string or buffer
Traceback (most recent call last):
  File "/usr/bin/docker-compose", line 11, in <module>
    sys.exit(main())
  File "/usr/lib/python2.7/site-packages/compose/cli/main.py", line 68, in main
    command()
  File "/usr/lib/python2.7/site-packages/compose/cli/main.py", line 118, in perform_command
    handler(command, command_options)
  File "/usr/lib/python2.7/site-packages/compose/cli/main.py", line 926, in up
    scale_override=parse_scale_args(options['--scale']),
  File "/usr/lib/python2.7/site-packages/compose/project.py", line 424, in up
    get_deps
  File "/usr/lib/python2.7/site-packages/compose/parallel.py", line 69, in parallel_execute
    raise error_to_reraise
TypeError: expected string or buffer

This is the steps to reproduce it:

(at your machine)
~ docker run --privileged -d docker:stable-dind
~ docker exec -ti *CONTAINER_ID* sh

(inside of the docker container)

~ apk add --no-cache py-pip vim
~ pip install docker-compose

(here edit a docker-compose.yml and paste the up yaml code)

~ docker-compose up

I don't know if is a problem with python, with docker, docker-compose....

Anybody can help me?

Thanks!

Answer 1

Error? the problem is most probably(not given) coming from your "docker-compose.yml" file, docker expected a string or bytes-like object but one or more of the values supplied doesn't conform to that format.

Solution - make sure the values supplied to your docker-compose.yml properties document are in the right format. For example one time , i had the wrong spacing in the following property: i.e it looked like;

ports:
   - 8000: 8000

but should have been

ports:
   - 8000:8000

Notice the spacing of the values supplied.

Answer 2

I encountered a similar error when working with a NestJS application on macOS.

When I run the command docker-compose up I get the error:

Traceback (most recent call last):
  File "docker-compose", line 3, in <module>
  File "compose/cli/main.py", line 81, in main
  File "compose/cli/main.py", line 200, in perform_command
  File "compose/cli/command.py", line 60, in project_from_options
  File "compose/cli/command.py", line 148, in get_project
  File "compose/config/config.py", line 423, in load
  File "compose/config/config.py", line 424, in <listcomp>
  File "compose/config/config.py", line 626, in process_config_file
  File "compose/config/validation.py", line 474, in validate_against_config_schema
  File "compose/config/validation.py", line 537, in handle_errors
  File "jsonschema/validators.py", line 328, in iter_errors
  File "jsonschema/_validators.py", line 282, in properties
  File "jsonschema/validators.py", line 344, in descend
  File "jsonschema/validators.py", line 328, in iter_errors
  File "jsonschema/_validators.py", line 23, in patternProperties
  File "jsonschema/validators.py", line 344, in descend
  File "jsonschema/validators.py", line 328, in iter_errors
  File "jsonschema/_validators.py", line 263, in ref
  File "jsonschema/validators.py", line 344, in descend
  File "jsonschema/validators.py", line 328, in iter_errors
  File "jsonschema/_validators.py", line 282, in properties
  File "jsonschema/validators.py", line 344, in descend
  File "jsonschema/validators.py", line 328, in iter_errors
  File "jsonschema/_legacy_validators.py", line 55, in items_draft3_draft4
  File "jsonschema/validators.py", line 344, in descend
  File "jsonschema/validators.py", line 328, in iter_errors
  File "jsonschema/_validators.py", line 337, in oneOf
  File "jsonschema/validators.py", line 344, in descend
  File "jsonschema/validators.py", line 328, in iter_errors
  File "jsonschema/_validators.py", line 45, in additionalProperties
  File "jsonschema/_utils.py", line 98, in find_additional_properties
  File "/Users/administrator/jenkins/workspace/dsg_compose_1.29.2/build/toolchain/Frameworks/Python.framework/Versions/3.9/lib/python3.9/re.py", line 201, in search
TypeError: expected string or bytes-like object
[21470] Failed to execute script docker-compose

Here's how I solved it

I checked the docker-compose.yml file and I realized that it did not have the container port specified. This was how the file looked:

version: "3"
services:
  web:
    image: my-app
    build: .
    container_name: my-app
    ports:
      - 8080:
    env_file: .env
    volumes:
      - ".:/app"

All I had to do was to add the container port which was 3001:

version: "3"
services:
  web:
    image: my-app
    build: .
    container_name: my-app
    ports:
      - 8080:3001
    env_file: .env
    volumes:
      - ".:/app"

That's all