Docker Cheat Sheet

T Docker Cheat Sheet

The following commands may be useful to students in SE courses at MSOE. You may need to put sudo in front of each:

Check Docker is installed and working:
```
$ docker run hello-world
```
Start up a container with a Bash prompt:
```
$ docker run -i -t ubuntu /bin/bash
```
List running containers:
```
$ docker ps
```
List all containers, including ones that have terminated:
```
$ docker ps -a
```
Deleting containers that are not currently: running
```
$ docker rm $(docker ps -aq)
```
Purging old images (that are no longer in use; this will result in forcing them to be downloaded again when you reference them):
```
$ docker image prune -a
```
Deleting all stopped images; this subsumes the image prune command:
```
$ docker system prune -a
```
Removing all images as well; it appears you need this plus the prune operation to delete all containers. Executing this can free up a lot of space on your drive.
```
$ docker rmi $(docker images -q)
```
The docker images -q command lists just the ids (with no other columns), and the $(...) turns that list into command-line arguments.
Build a Docker image from a Dockerfile, get it's id number, and then restart it with a Bash prompt so you can explore the container:
```
$ docker build ./
$ docker ps -a
$ docker run -t -i XXXXXX /bin/bash
```
where the XXXXXX is the image id (such as 997485f46ec4) from the second column of the ps -a output. Note the status can give you an idea of how long ago you ran the container.