# 🐳 Day 4: Mastering docker ps Command - With examlpe’s! This guide provides a deep dive of the `docker ps` command, including how to list, filter, format, and count containers and images. Docker ps command lists containers on your system. It displays useful information such as container IDs, image names, uptime, exposed ports and many more.. It's an essential tool to working with the containers. 🐳📋 ## 🎬 Video Demonstration [![Watch on Youtube](https://camo.githubusercontent.com/ff0e51ba4fe62e7e72e3b21b5287bb8442e5f58ce9d96b8f034025d6137a0b6b/68747470733a2f2f692e7974696d672e636f6d2f76692f373376524674736e6d76492f6d617872657364656661756c742e6a7067 align="left")](https://youtu.be/73vRFtsnmvI) ## 📋 Basic Usage ### ❔ Get Help using help command ```plaintext docker ps --help ``` ```plaintext Usage: docker ps [OPTIONS] List containers Aliases: docker container ls, docker container list, docker container ps, docker ps Options: -a, --all Show all containers (default shows just running) -f, --filter filter Filter output based on conditions provided --format string Format output using a custom template: 'table': Print output in table format with column headers (default) 'table TEMPLATE': Print output in table format using the given Go template 'json': Print in JSON format 'TEMPLATE': Print output using the given Go template. Refer to https://docs.docker.com/go/formatting/ for more information about formatting output with templates -n, --last int Show n last created containers (includes all states) (default -1) -l, --latest Show the latest created container (includes all states) --no-trunc Don't truncate output -q, --quiet Only display container IDs -s, --size Display total file sizes ``` ### 1\. Show Running Containers ```plaintext docker ps ``` ### 2\. Show All Containers (Running + Stopped) ```plaintext docker ps -a ``` ### 3\. Show Disk Usage per Container ```plaintext docker ps -s docker ps -as ``` ### 4\. Show Last N Created Containers ```plaintext docker ps --last 4 # or docker ps -n 4 ``` ### 5\. Show the Most Recently Created Container ```plaintext docker ps -l # or docker ps --latest ``` ### 6\. Show Only container IDs ```plaintext docker ps -q docker ps -aq # or docker ps --quiet docker ps -a --quiet ``` --- ## 🔍 Filtering Containers ### Filter by Name ```plaintext docker ps -f "name=test-container" or docker ps --filter "name=test-container" ``` ### Filter by Container ID ```plaintext docker ps -a -f "id=aca09d8707d8" or docker ps -a --filter "id=aca09d8707d8" ``` ### Filter by Status ```plaintext docker ps --filter status=running docker ps --filter status=exited ``` ### Filter by Ancestor (Image) ```plaintext docker ps --filter ancestor=nginx ``` ### Filter by Creation Time before/after container ```plaintext docker ps -f before=whoami docker ps -f since=nd ``` ### Sort containers by creation time (most recent first) ```plaintext docker ps -a --format '{{.CreatedAt}}\t{{.Names}}' | sort -r ``` ### Filter by Network, Volume, Port, Label, Health ```plaintext docker ps --filter publish=8080 docker ps --filter "label=com.example.app=web" docker ps --filter health=healthy docker ps --filter network=bridge docker ps --filter volume=myvol docker ps -a --filter exited=0 ``` ### Multiple Filters ```plaintext docker ps --filter status=running --filter ancestor=nginx ``` ## 🔢 Counting Containers ### Count Running Containers ```plaintext docker ps -q | wc -l ``` ### Get Count via Docker Info ```plaintext docker info --format '{{json .ContainersRunning}}' ``` ### Count All Containers (Running + Stopped) ```plaintext docker ps -a -q | wc -l ``` ### Count Matching Containers by Image Name ```plaintext docker ps | grep ibraransaridocker/coming-soon | wc -l ``` ## 🛠️ Custom Formatting ### Simple Name Format ```plaintext docker ps --format '{{.Names}}' or docker ps -a --format "{{.Names}}" or docker ps -a --format "table {{.Names}}" ``` ### Detailed Format with Variables ```plaintext FORMAT="\nID\t{{.ID}}\nIMAGE\t{{.Image}}\nCOMMAND\t{{.Command}}\nCREATED\t{{.RunningFor}}\nSTATUS\t{{.Status}}\nPORTS\t{{.Ports}}\nNAMES\t{{.Names}}\n" docker ps -a --format="$FORMAT" ``` ### Tabular Format Output ```plaintext docker ps -a --format "table {{.Names}}\t{{.ID}}\t{{.Status}}\t{{.Ports}}\t{{.Image}}\t{{.Command}}\t{{.RunningFor}}" ``` --- ## 🔍 Inspect Available Format Fields ### View Raw Output in JSON ```plaintext docker ps --format '{{json .}}' | jq ``` ### List All Available Format Keys ```plaintext docker ps --format '{{json .}}' | jq -r 'keys_unsorted[]' | sort -u ``` ### List All Format Keys from All Containers ```plaintext # Create sample container to provide all keys docker run -itd \ --name test-container \ --hostname custom-hostname \ --env MY_ENV=example \ --label app=demo \ --label com.example.app=web \ --mount type=bind,source=/tmp,target=/app/tmp,readonly \ --mount type=volume,source=myvol,target=/app/data \ --network bridge \ --publish 8080:80 \ --restart unless-stopped \ --memory 512m \ --cpu-shares 512 \ --health-cmd="curl -f http://localhost || exit 1" \ --health-interval=30s \ --health-retries=3 \ --health-start-period=5s \ nginx:latest # Run to get key docker inspect $(docker ps -q) | jq '.[0] | keys_unsorted' | sort -u # or docker inspect $(docker ps -q) | jq -r '.[0] | keys_unsorted[]' | sort -u ``` --- ## 🧩 All Available `--format` Fields Here are all the fields you can use with `--format`: | Field | Description | | --- | --- | | `.ID` | Container ID | | `.Names` | Container name(s) | | `.Image` | Image name | | `.ImageID` | Image ID | | `.Command` | Startup command | | `.CreatedAt` | Creation time | | `.RunningFor` | Time running | | `.Ports` | Port mappings | | `.Status` | Status string | | `.Size` | Disk usage size (needs `-s`) | | `.Labels` | All labels | | `.Label` | Specific label (e.g., `{{.Label "key"}}`) | | `.Mounts` | Mount points | | `.Networks` | Networks attached | | `.State` | Running, exited, paused, etc. | | `.Health` | Healthcheck status | --- ## 📚 More Info For full details, check the [official Docker formatting docs](https://docs.docker.com/engine/cli/formatting/) 📘 ### Happy Dockering! 🐳✨