CODEWITHSUNDEEP
docker
Kenny_I
Kenny_I

Reputation: 2513

How docker containerize a simple Rest API? New container not listed with docker ps

I'm following these instructions to containerize a simple Rest API using Python Flask. https://bpostance.github.io/posts/docker-fask-api/

This command works:

docker build -t demo/flask-api:0.0 .

I can see new images with

docker images

However there seems to be problem with this: (no errors)

docker run --name demo-flask-api -d -p 5000:5000 demo/flask-api:0.0

I don't see new images with (no errors)

docker ps

And I can not open http://localhost:5000/ or http://localhost:5000/api?value=2

Upvotes: 0

Views: 153

Answers (1)

Turing85
Turing85

Reputation: 20195

When we build the image and start it with an interactive shell:

cd deng.learn/docker/conda-flask-api
docker build -t test .
docker run --rm -it --entrypoint /bin/bash test

We can inspect the container. A ls in the container shows that everything looks fine:

(base) root@df3506215bdb:/home/flask-api# ls
app  environment.yml  serve.sh

But when we try to run the serve.sh script within the container, we see this:

(base) root@df3506215bdb:/home/flask-api# ./serve.sh
bash: ./serve.sh: /bin/bash^M: bad interpreter: No such file or directory

This indicates a problem with the line endings. The file serve.sh contains windows line endings (\r\n), which the shell does not understand properly. When we replace the windows line endings in this file with linux line endings (\n), rebuilt the container, and start it:

docker build -t test . && docker run --rm -d -p 5000:5000 test

then a subsequent docker ps will show the container up and running:

docker ps
CONTAINER ID   IMAGE     COMMAND        CREATED          STATUS          PORTS                    NAMES
3179071939ec   test      "./serve.sh"   36 seconds ago   Up 37 seconds   0.0.0.0:5000->5000/tcp   elastic_lalande

And the application is accessible through http://localhost:5000.

Upvotes: 1

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