Docker CMD not accepting build arg-CodePudding

DockerFile

    FROM thoom/pyresttest
    ARG url
    ENV api_url=$url
    COPY ./tests usr/src/app
    WORKDIR usr/src/app
    ENTRYPOINT [ "pyresttest" ]
    RUN echo "Oh dang look at that $url"
    CMD [ "$api_url","api_test.yml" ]

api_test.yml

- config:
      - testset: "Basic tests"
      - timeout: 100 # Increase timeout from the default 10 seconds
- test:
      - name: "get"
      - url: "/prod/URLS"
      - method: "GET"
      - expected_status: [200]

- test:
      - name: "post"
      - url: "/prod/URLS"
      - method: "POST"
      - body: '{ "url_name": "www.youtube.com" }'
      - headers: { "Content-Type": "application/json" }
      - expected_status: [200]
      - extract_binds:
            - "id": { "jsonpath_mini": "Item.url_id" }

- test:
      - name: "post"
      - url: "/prod/URLS"
      - method: "PATCH"
      - body: { template: '{"url_name": "www.cnn.com","url_id": "$id"}' }
      - headers: { "Content-Type": "application/json" }
      - expected_status: [200]

- test:
      - name: "post"
      - url: "/prod/URLS"
      - method: "DELETE"
      - body: { template: '{"url_id": "$id"}' }
      - headers: { "Content-Type": "application/json" }
      - expected_status: [200]

docker build -t rest-api-test . --build-arg url=myapiurl.com

Im trying to pass my url as build argument to my Dockerfile when I build it but for some reason its not accepting it in CMD and when I run my build file all my tests fail due to url. But when I hardcode my url in CMD all my tests work then. Why CMD is not accepting my url which I'm passing in my --build-args ?

PS: Trying to learn docker because I'm new

CodePudding user response：

You're using the exec form of the CMD statement. That doesn't run a shell, so you can't use environment variables in your command.

You can run a shell in your CMD statement in 2 ways. Either use the shell form

CMD $api_url api_test.yml

or the exec form where you run the shell explicitly

CMD ["/bin/sh", "-c", "$api_url apt_test.yml"]