Docker container exited with exit code 2 "sh can't open 'start_script.sh': No such file or directory"

Question

I have the following Dockerfile that we use to start Django servers with:

    FROM python:3.7.4-alpine3.10
    LABEL maintainer = ******
    
    ENV PYTHONUNBUFFERED 1S
    ENV RUNNING_IN_DOCKER True
    
    RUN apk add --update --no-cache build-base postgresql-client exiftool jpeg-dev zlib-dev gettext git openssl
    RUN apk add --update --no-cache gcc libc-dev linux-headers postgresql-dev file-dev py-magic libffi-dev libxml2-dev
    
    COPY ./requirements.txt /requirements.txt
    RUN pip install -r /requirements.txt
    
    RUN mkdir /app
    
    WORKDIR /app
    
    CMD sh start_script.sh

and the following docker-compose.yml:

    version: '3'
    
    services:
      backend:
        build: .
        restart: always
        ports:
          - 127.0.0.1:****:****
        env_file:
          - .env
        environment: &app-env
          - POSTGRES_HOST=db
          - POSTGRES_PORT=${POSTGRES_PORT}
          - POSTGRES_DB=${POSTGRES_DB}
          - POSTGRES_USER=${POSTGRES_USER}
          - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
          - REDIS_HOST=redis
          - REDIS_PORT=${REDIS_PORT}
        depends_on: &app-dep
          - db
          - redis
        volumes: &app-vol
          - ./app
      db:
        image: postgres:10-alpine
        restart: always
        ports:
          - ${POSTGRES_PORT}:****
        environment:
          - POSTGRES_DB=${POSTGRES_DB}
          - POSTGRES_USER=${POSTGRES_USER}
          - POSTGRES_PASSWORD=${POSTGRES_PASSWORD}
        volumes:
          - ${LOCAL_POSTGRES_DB_DATA}:/var/lib/postgresql/data
      redis:
        image: redis:5-alpine
        command: ["redis-server", "--appendonly", "yes"]
        restart: unless-stopped
        ports:
          - ${REDIS_PORT}:****
        volumes:
          - ${LOCAL_REDIS_DATA}:/data

When I try to run it I get the following output in my docker-compose logs:

    Attaching to api_backend_1, api_redis_1, api_db_1
    backend_1  | sh: can't open 'start_script.sh': No such file or directory
    backend_1  | sh: can't open 'start_script.sh': No such file or directory
    backend_1  | sh: can't open 'start_script.sh': No such file or directory
    backend_1  | sh: can't open 'start_script.sh': No such file or directory
    backend_1  | sh: can't open 'start_script.sh': No such file or directory
    backend_1  | sh: can't open 'start_script.sh': No such file or directory
    db_1       | 
    db_1       | PostgreSQL Database directory appears to contain a database; Skipping initialization
    db_1       | 
    db_1       | 2020-09-25 09:14:20.936 UTC [1] LOG:  listening on IPv4 address "0.0.0.0", port ****
    db_1       | 2020-09-25 09:14:20.936 UTC [1] LOG:  listening on IPv6 address "::", port ****
    db_1       | 2020-09-25 09:14:20.945 UTC [1] LOG:  listening on Unix socket "/var/run/postgresql/.s.PGSQL.5432"
    db_1       | 2020-09-25 09:14:20.965 UTC [20] LOG:  database system was shut down at 2020-09-25 09:14:10 UTC
    db_1       | 2020-09-25 09:14:20.970 UTC [1] LOG:  database system is ready to accept connections
    redis_1    | 1:C 25 Sep 2020 09:14:20.818 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
    redis_1    | 1:C 25 Sep 2020 09:14:20.818 # Redis version=5.0.9, bits=64, commit=00000000, modified=0, pid=1, just started
    redis_1    | 1:C 25 Sep 2020 09:14:20.818 # Configuration loaded
    redis_1    | 1:M 25 Sep 2020 09:14:20.819 * Running mode=standalone, port=****.
    redis_1    | 1:M 25 Sep 2020 09:14:20.819 # Server initialized
    redis_1    | 1:M 25 Sep 2020 09:14:20.819 # WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
    redis_1    | 1:M 25 Sep 2020 09:14:20.819 # WARNING you have Transparent Huge Pages (THP) support enabled in your kernel. This will create latency and memory usage issues with Redis. To fix this issue run the command 'echo never > /sys/kernel/mm/transparent_hugepage/enabled' as root, and add it to your /etc/rc.local in order to retain the setting after a reboot. Redis must be restarted after THP is disabled.
    redis_1    | 1:M 25 Sep 2020 09:14:20.819 * Ready to accept connections
    api_backend_1 exited with code 2
    api_backend_1 exited with code 2

This is the file structure:

/ git_repository
| - /app
| - requirements.txt
| - Dockerfile
| - docker-compose.yml
| - start_script.sh PERMISSIONS: -rwxrwxr-x 1 ubuntu ubuntu   208 Sep 25 08:11

The weird thing is that we have another service with the exact same Dockerfile and structure that does work correctly...

The only thing I could find that might be wrong is in the Dockerfile the workingdir is changed to /app before running start_script.sh, but changing the run command to CMD sh ../start_script.sh didn't change the error. The copy of requirements.txt also doesn't make sense to me but that is unrelated to this error I think

While searching I came across this post about line endings but that fix also didn't work for me.

I'm not sure how to proceed from here, or how I can debug this further, does anyone see what's wrong or have tips that I can try?

Solution

As per the comments on my question I used docker-compose run backend sh to inspect my container. It turned out that I indeed didn't copy any source code or the start_script.sh to my container. I made changes to my Dockerfile to make it work:

FROM python:3.7.4-alpine3.10
LABEL maintainer = ******

ENV PYTHONUNBUFFERED 1S
ENV RUNNING_IN_DOCKER True

RUN apk add --update --no-cache build-base postgresql-client exiftool jpeg-dev zlib-dev gettext git openssl
RUN apk add --update --no-cache gcc libc-dev linux-headers postgresql-dev file-dev py-magic libffi-dev libxml2-dev

RUN mkdir /app
COPY ./start_script.sh /app/start_script.sh.      --------> Copy the start_script.sh
COPY ./requirements.txt /app/requirements.txt
RUN pip install -r /app/requirements.txt

COPY . /app                                       --------> Copy the source code
WORKDIR /app

CMD sh start_script.sh

Comments

[urfin78]

With WORKDIR you change the the working directory for the following CMD statement. See documentation If start_script.sh is not in /app directory you have to specify a path so CMD /start_script.sh should work. But why you're changing the WORKDIR anyway?

[David Maze]

It doesn't look like you COPY the script or any of your source code into the image, which would produce that error. Have you tried looking with something like docker-compose run backend sh to get an interactive shell in the container to see what's actually there?

[NG.]

@urfin78 thanks I will try that. I'm not sure why I'm changing the workdir, I took over this project just before deployment. I am looking at django dockerfiles to see if it's a django specific thing.

[NG.]

@DavidMaze thanks! I will try to get an interactive shell to see what's going on. I'm new to docker so I didn't know that was an option! I was having trouble getting information on what's going on but this seems like a good option to try.