How to list running and all Docker containers?

docs.questions.sections.docker~2 min read

Listing containers is the first command anyone learns and the one most often used. Two flags do almost everything: -a for all states, --filter and --format for everything else.

Theory

TL;DR

docker ps = running containers only.
docker ps -a = every container the daemon knows about (running, paused, exited, dead, created).
docker ps -q = quiet mode, just container IDs (one per line).
Combine with --filter for status/name/label/network/image queries.
Use --format for custom columns or JSON output. Replaces grep/awk pipelines.
docker container ls is the long-form alias for the same command.

Quick example

bash

# Default: running containers only
$ docker ps
CONTAINER ID   IMAGE              COMMAND                  STATUS         PORTS                  NAMES
a3f9d2b8c1e4   nginx:1.27-alpine  "/docker-entrypoint…"   Up 5 minutes   0.0.0.0:8080->80/tcp   web
b7e1f4d6a2b8   postgres:16        "docker-entrypoint.s…"   Up 5 minutes   5432/tcp               db

# All states (running + exited + ...)
$ docker ps -a
CONTAINER ID   IMAGE              ...   STATUS                       NAMES
a3f9d2b8c1e4   nginx:1.27-alpine  ...   Up 5 minutes                 web
b7e1f4d6a2b8   postgres:16        ...   Up 5 minutes                 db
c2d8e3f5a1b7   alpine             ...   Exited (0) 2 hours ago      one-off-test

# IDs only (great for piping)
$ docker ps -aq
a3f9d2b8c1e4
b7e1f4d6a2b8
c2d8e3f5a1b7

Useful flag combinations

bash

# Filter by state
docker ps --filter status=running        # default
docker ps --filter status=exited         # only stopped
docker ps --filter status=paused

# Filter by name (substring match)
docker ps --filter name=web

# Filter by image
docker ps --filter ancestor=nginx:1.27-alpine

# Filter by label
docker ps --filter label=env=prod

# Combine filters (AND)
docker ps -a --filter status=exited --filter name=test

# Show last N created
docker ps -an 5

# Show only the latest one
docker ps -al

`--format` for custom output

bash

# Tab-separated columns
$ docker ps --format 'table {{.Names}}\t{{.Status}}\t{{.Ports}}'
NAMES   STATUS         PORTS
web     Up 5 minutes   0.0.0.0:8080->80/tcp
db      Up 5 minutes   5432/tcp

# Each container as one JSON line (perfect for jq)
$ docker ps --format json | jq '.Names'
"web"
"db"

# Just names, one per line
$ docker ps --format '{{.Names}}'
web
db

Format strings let you skip the awk dance.

Common mistakes

Wondering why a container is missing

bash

$ docker ps                        # empty (or missing your container)
$ docker ps -a                     # there it is, in Exited state

A crashed or completed container is not in ps's default output. Always check -a when a container disappears.

Using grep when --filter exists

bash

# WRONG: fragile, breaks on substring overlaps
$ docker ps | grep myapp

# RIGHT: structured filter
$ docker ps --filter name=myapp

The filter is exact about what it matches; grep is not.

Forgetting -q when piping to delete

bash

# WRONG: passes the entire table including "CONTAINER ID" header
$ docker rm $(docker ps -a)
Error response from daemon: No such container: CONTAINER

# RIGHT: -q gives only IDs
$ docker rm $(docker ps -aq)

The canonical "nuke all containers" one-liner is docker rm -f $(docker ps -aq).

Real-world usage

docker ps -a after a CI build — find the build container's exit code from its Status field.
docker ps --filter name= in shell scripts — check if a service is running before doing something.
docker ps --format json | jq in monitoring — feed structured data into health dashboards.
docker ps -aq | xargs docker rm -f in cleanup hooks — wipe everything between test runs.

Follow-up questions

Q: What is the difference between docker ps and docker container ls?

A: Same command. docker ps is the legacy short form, docker container ls is the modern long form. Identical behavior and flags. Most people still type ps.

Q: How do I see resource usage (CPU, memory) per container?

A: docker stats (live) or docker stats --no-stream (snapshot). Different command than ps; ps lists, stats measures.

Q: Can I see containers from a specific Docker Compose project only?

A: Yes: docker ps --filter label=com.docker.compose.project=<project-name>. Or use docker compose ps from the project directory.

Q: Why does my docker ps output get cut off?

A: Long commands and image names get truncated by default. Use --no-trunc for full strings, or --format to print only the columns you care about.

Q: (Senior) How would you write a one-liner to remove all containers older than a day?

bash

docker ps -a --filter status=exited \
  --format '{{.ID}} {{.CreatedAt}}' \
  | awk -v d="$(date -d 'yesterday' --iso-8601=seconds)" '$2 < d {print $1}' \
  | xargs -r docker rm

Or more simply, docker container prune --filter 'until=24h' does the same thing without manual date math.

Examples

Find and tail logs of the most recent container

bash

$ docker logs $(docker ps -alq)
# -a (all states) -l (latest) -q (just ID) → one container ID
# Then docker logs prints its output.

Quick way to see what a recently-exited container said before dying.

Cleanup all stopped containers older than an hour

bash

$ docker container prune --filter 'until=1h' -f
Deleted Containers:
c2d8e3f5a1b7...
b9a4f1e2d8c3...

Total reclaimed space: 12.4MB

Built-in prune saves the manual filter+xargs pipeline for the common case.

Check if a service is up before continuing

bash

# In a shell script
if docker ps --filter name=db --filter status=running -q | grep -q .; then
  echo "DB is up"
else
  echo "DB not running"
  exit 1
fi

Useful in deploy scripts and CI checks. The -q plus grep -q . returns true only if at least one container matches.

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