How to let docker container install latest dependencies version-CodePudding

I have a docker image that is build from Dockerfile. It has pip installation inside with custom library. Now the image is used in docker-compose service.

requirements.txt

example-library-1
example-library-2

Dockerfile

FROM python:3.7-alpine
WORKDIR /code
COPY requirements.txt requirements.txt
RUN pip install -r requirements.txt
COPY . .
CMD ["flask", "run"]

docker build -t example_user/example_image .

docker-compose.yml

version: "3.9"
services:
  web:
    image: example_user/example_image
    ports:
      - "8000:5000"

When I have a new version for example-library-1, how do I update the docker-compose service to use the new library?

I had tried docker-compose up -d and docker-compose restart web but it does not check for new library version.

Is there a way to do this without docker-compose down and docker-compose up -d?

CodePudding user response：

You can add a build key to the compose file.

services:
  web:
    image: example_user/example_image
    build:
      context: path/to/context
      dockerfile: path/to/Dockerfile

Then you run compose with the build flag.

docker compose up --build

That said, compose does not have something like rolling updates. You need to stop to compose service and do up with the build flag in order to rebuild.

If you need to rolling updates, you need to use a different operator, like swarm or Kubernetes.

CodePudding user response：

The docker-compose build flag is a good idea.

After that I recommend to use --no-cache flag because the docker buildkit may cache some layer.

Check here the documentation.

Don't forget to check the DOCKER_BUILDKIT environment variable too.