Basic Container Operations

Master the essentials of Docker CLI to create, manage, and troubleshoot containers efficiently. This guide covers key commands, options, and best practices for container operations.

Table of Contents

• Quick Syntax Reference
• Command Syntax Styles
• Creating a Container
• Listing Containers
• Starting a Container
• Create & Start in One Step
• Ephemeral Containers
• Interactive Shells
• Exiting Containers
• Naming Containers
• Detached Mode
• Links and References

Quick Syntax Reference

Use this general pattern for Docker commands:

docker [object] [command] [options] [arguments]

Examples:

docker image ls
docker container run -it ubuntu
docker image build .
docker container attach <container>
docker container kill <container>

Command Syntax Styles

Docker supports both legacy and grouped syntax. We’ll use the grouped style throughout this guide.

Creating a Container

To create (but not start) a container:

docker container create httpd

Sample output:

Unable to find image 'httpd:latest' locally
latest: Pulling from library/httpd
…
Status: Downloaded newer image for httpd:latest
36a391532e10d45f772f2c9430c2cc38dad4b441aa7a1c444d59f6fa3d78c6b6

On Linux, Docker stores images and container metadata under /var/lib/docker/:

ls /var/lib/docker/
# builder  buildkit  containers  image  network  overlay2  plugins  runtimes  swarm  tmp  trust  volumes

Each container’s data lives in containers/<container-ID>/.

Listing Containers

Use docker container ls with options to filter the output:

docker container ls -a

Sample output:

CONTAINER ID   IMAGE     COMMAND              CREATED         STATUS                     NAMES
36a391532e10   httpd     "httpd-foreground"   2 minutes ago   Created                    charming_wiles

Docker assigns a random human-readable name if you don’t provide one.

Starting a Container

Start an existing container by its ID or name:

docker container start 36a391532e10
docker container ls

Create & Start in One Step

Pull the image, create, and start the container:

docker container run httpd

Ephemeral Containers

Some images (like ubuntu) don’t run a persistent process:

docker container run ubuntu
docker container ls -a

Output:

CONTAINER ID   IMAGE    COMMAND     CREATED         STATUS                     NAMES
d969ecdb44ea   ubuntu   "/bin/bash" 2 minutes ago   Exited (0) 2 minutes ago   intelligent_almeida

Once the primary process exits, the container stops.

Interactive Shells

Keep STDIN open and allocate a pseudo-TTY with -it:

docker container run -it ubuntu

Inside the container:

root@6caba272c8f5:/# hostname
6caba272c8f5

On the host:

docker container ls

Shows:

CONTAINER ID   IMAGE    COMMAND      CREATED          STATUS              NAMES
6caba272c8f5   ubuntu   "/bin/bash"  About a minute   Up About a minute   quizzical_austin

Exiting Containers

Running exit inside an interactive shell stops the container:

docker container run -it ubuntu
root@6caba272c8f5:/# exit
exit
docker container ls -a

Naming Containers

Assign a custom name at creation:

docker container run -itd --name webapp ubuntu
docker container ls -l

Output:

CONTAINER ID   IMAGE    COMMAND      CREATED          STATUS             NAMES
59aa5eacd88c   ubuntu   "/bin/bash"  20 seconds ago   Up 19 seconds      webapp

Rename an existing container:

docker container rename intelligent_almeida webapp2

Detached Mode

Run containers in the background with -d:

docker container run -d httpd

Sample output:

11cbd7fe7e65a9da453e159ed0fe163592dcc8a7845abc91b8305c78f50ac70

To reattach:

docker container attach 11cbd7fe7e65

A unique ID prefix is sufficient if it’s unambiguous.

Links and References

• Docker CLI Reference
• Docker Container Commands
• Docker Official Documentation