"docker container logs" - Fetch Logs

Q

How to fetch log messages from a container with the "docker container logs" command?

✍: FYIcenter.com

A

Most Docker container applications print log messages to its console to report statuses and debug information.

You can fetch log messages from a container with the "docker container logs" command at any time, even after it's been stopped.

1. Create a new container from the "hello-world" image and run it. You see log messages printed, because the "docker container run" command attaches the container console by default.

$ docker container run --name my_hello hello-world

Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
1b930d010525: Pull complete
Digest: sha256:6f744a2005b12a704d2608d8070a494ad1145636eeb74a570c56b94d94ccdbfc
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/

2. Check the new container status. You see the container has exited from its execution. It is stopped now.

$ docker container list --latest

CONTAINER ID  IMAGE        COMMAND   CREATED         STATUS                     NAMES
54e2e688aa2f  hello-world  "/hello"  5 seconds ago   Exited (0) 5 seconds ago   awesome_chandrasekhar

3. Fetch log messages from the stopped container.

$ docker container logs my_hello

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/

As you can see, we can fetch log messages at any time from a container.

 

Alpine Linux Docker Image

"docker container start --attach" - Attach Console

Docker Client (or CLI) on Ubuntu

⇑⇑ Docker Container Platform - Tutorials

2019-06-29, 134👍, 0💬