# Docker troubleshooting tips and tricks

Docker is a great way to run web apps on your server.  However there are times when problems can arise and figuring out where the trouble is can be tricky.  Here are a few commands that can help you figure out the cause of the trouble.
 
`docker-compose up` without the -d gives you an interactive look as your container loads.  Depending on the container, the information provided can be very useful in tracking down the problem.

`docker-compose up -d --build` starts docker and builds image `docker-compose up -d` starts docker image. 

`docker container ls` lists all the active containers and shows each container id. `docker container ls -a` shows containers that are not running also.

 `docker exec -it docker_container_id sh` allows you to sh into a container so you can run commands inside of the container.  Also you don't just need to sh, you can run commands on your database, etc. `docker exec -i docker_container_id /usr/bin/psql -h db -U postgres -d my_db`

`docker container ls --format "table {{.ID}}\t{{.Names}}\t{{.Ports}}" -a` Find all of the ports in use on your docker containers with their internal and external network ports.  Very useful for troubleshooting your network connections.

`docker network ls` shows your network names and ids.

`docker network rm network_name` removes a network.

`docker network create network_name` creates a network.

`docker container rm docker_container_id` removes a container.

`docker-compose down --volumes` sometimes you want to reinstall a container and get rid of any data stored locally in volumes.  This command also eliminates the stored volume data.  Very useful when you need to redo a container from scratch.

`docker container prune` remove all stopped containers.

`docker volume prune` remove all stopped volumes.

`docker network prune` remove all stopped networks.

`docker inspect container_name` get lots of interesting info about a container.

`docker stop container_id` stops current container also `docker kill container_id` .

` docker-compose up --build --force-recreate --no-deps` force a container to rebuild from scratch.  Sometimes the containers do not properly rebuild when they are changed.