Docker API v1.40 getting container logs

Question

I'm trying to retrieve container logs using Docker API.

Open API documentation of Docker states to get the container logs; syntax that should be used is;

/containers/{id}/logs

According to documentation there could be three response statuses; 200, 404 and 500.

You can see the part of the documentation below;

responses:
        200:
          description: |
                  logs returned as a stream in response body.
                  For the stream format, [see the documentation for the attach endpoint](#operation/ContainerAttach).
                  Note that unlike the attach endpoint, the logs endpoint does not upgrade the connection and does not
                  set Content-Type.
          schema:
            type: "string"
            format: "binary"
        404:
          description: "no such container"
          schema:
            $ref: "#/definitions/ErrorResponse"
          examples:
            application/json:
              message: "No such container: c2ada9df5af8"
        500:
          description: "server error"
          schema:
            $ref: "#/definitions/ErrorResponse"

The interesting part for me is when I make a call I get 400 error which doesn't exist in the docs. Response message is like;

{
    "message": "Bad parameters: you must choose at least one stream"
}

How can I get the container logs using Docker API ?

score 2 · Accepted Answer · answered Dec 10 '19 at 08:00

2

Specify where to return logs from by sending the stdout or stderr query parameters. Example:

curl --unix-socket /var/run/docker.sock http://localhost/containers/containerId/logs?stdout=true

answered Dec 10 '19 at 08:00

b0gusb

4,283
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score 0 · Answer 2 · answered Feb 07 '23 at 08:36

Using Docker API in Python it can be done like that:

import docker
from docker.models.containers import Container

image_id: str = "the_image_id_that_you_get_from_building"
container_object: Container = docker.from_env().containers.run(
    image_id,
    name="that-nice-name",
    detach=True,
)
for log_line in container_object.logs(stream=True):
    print(log_line.decode("utf-8"), end="")

The execution stops on the for loop - printing all the logs as they appear in the container. As soon as the container exits (is terminated for any reason) the execution leaves the for loop.

Docker API v1.40 getting container logs

2 Answers2