Hosting Operations
Read-only, can be slowShow Containers in a Clean Triage Table
You need a fast view of container state, image, uptime, and published ports without wrapped columns hiding the important parts.
Command
docker ps -a --format 'table {{.Names}}\t{{.Status}}\t{{.Image}}\t{{.Ports}}'Before you run this
System impact: Read-only. Can create load on large logs, directories, filesystems, or process tables.
When not to use it: Do not treat it as an application health check; it reports Docker state, not whether the app works.
Expected output
A table with container names, statuses, images, and port mappings.
System impact
Read-only, can be slow. Nothing changes. Docker prints container metadata in a narrower table.
Scope this to the smallest useful path or service on busy systems.
Recovery / rollback: no state is changed.
When to use it
Use during first-response container triage to see what is running, stopped, restarting, or exposing ports.
When not to use it
Do not treat it as an application health check; it reports Docker state, not whether the app works.
Watch this command run
Command transcript
This sanitized transcript shows the commands and output shape without exposing host details.
$ docker ps -a --format 'table {{.Names}}\t{{.Status}}\t{{.Image}}\t{{.Ports}}'
NAMES STATUS IMAGE PORTS
web Up 2 hours (healthy) nginx:1.27 0.0.0.0:8080->80/tcp
api Restarting (1) 18 seconds ago registry.example/api:v1.9.4 0.0.0.0:9000->9000/tcp
worker Exited (0) 3 hours ago registry.example/worker:v1.9.4$ docker ps --format 'table {{.Names}}\t{{.Status}}\t{{.Ports}}'
NAMES STATUS PORTS
web Up 2 hours (healthy) 0.0.0.0:8080->80/tcpView commands shown
These are the commands shown in the sanitized transcript.
Commands shown
docker ps -a --format 'table {{.Names}}\t{{.Status}}\t{{.Image}}\t{{.Ports}}'docker ps --format 'table {{.Names}}\t{{.Status}}\t{{.Ports}}'
next steps
Related commands
Find Restarting Containers Fast
Restart loops hide in plain sight unless you filter for them.
docker ps -a --filter status=restarting --format 'table {{.Names}}\t{{.Status}}\t{{.Image}}'
Snapshot Container CPU and Memory
Get Docker resource usage once, without leaving a live dashboard running.
docker stats --no-stream --format 'table {{.Name}}\t{{.CPUPerc}}\t{{.MemUsage}}\t{{.NetIO}}\t{{.BlockIO}}'
Check Container Health Status
Docker may say a container is running while its health check says otherwise.
docker inspect --format '{{.Name}} health={{if .State.Health}}{{.State.Health.Status}}{{else}}none{{end}} status={{.State.Status}}' web
See Container Network Attachments
A container can be healthy and still attached to the wrong network.
docker inspect --format '{{.Name}} {{range $name, $net := .NetworkSettings.Networks}}{{$name}} {{$net.IPAddress}} {{end}}' api
Summarize Docker Disk Usage
See how Docker storage is split across images, containers, volumes, and cache.
docker system df -v
Study mapping
Use this as independent command practice: read the notes, predict the output, then compare it with the example before using a real shell.
Useful for
- LPIC-1 style command-line practice
- LFCS style performance tasks
- Linux+ style troubleshooting review
Independent study support only. No affiliation, endorsement, exam dumps, or real exam questions.