Docker Commands Cheat Sheet.

# Docker Cheatsheet

This cheatsheet provides a collection of commonly used docker commands.

## Getting Started

# Docker Cheatsheet


This cheatsheet provides a collection of commonly used docker commands.


## Getting Started


The getting started guide on Docker has detailed instructions for setting up [Docker].


After setup is complete, run the following commands to verify the success of installation:


### _PLEASE NOTE POST INSTALLATION STEPS BELOW IF YOU HAVE TO PREPEND SUDO TO EVERY COMMAND_


* **docker version** - provides full description of docker version
* **docker info** - display system wide information
* **docker -v** - provides a short description of docker version
* **docker run hello-world** - pull hello-world container from registry and run it


Have a look at the [free training] offered by Docker.


Have a look at the [repository] of images offered by Docker.


### Optional Post Installation Steps


To create the docker group and add your user:


* Create the docker group


? ```bash
? sudo groupadd docker
? ```


* Add your user to the docker group


? ```bash
? sudo usermod -aG docker $USER
? ```


* Log out and log back in so that your group membership is re-evaluated.
* Verify that you can run docker commands without sudo.


---


## Docker Commands


### Get docker info


#### General


Command | Description
--- | ---
docker version | provides full description of docker version
docker -v | provides a short description of docker version
docker info | display system wide information
docker info --format '{{.DriverStatus}}' | display 'DriverStatus' fragment from docker information
docker info --format '{{json .DriverStatus}}' | display 'DriverStatus' fragment from docker information in JSON format


### Manage Images


Command | Description
--- | ---
docker image ls | shows all local images
docker image ls --filter 'reference=ubuntu:16.04' | show images filtered by name and tag
docker image pull [image-name] | pull specified image from registry
docker image rm [image-name] | remove image for specified _image-name_
docker image rm [image-id] | remove image for specified _image-id_
docker image prune | remove unused images


### Search Images


Command | Description
--- | ---
docker search [image-name] --filter "is-official=true" | find only official images having *[image-name]*
docker search [image-name] -- filter "stars=1000" | find only images having specified *[image-name]* and 1000 or more stars


### Manage Containers


#### Display Container Information


Command | Description
--- | ---
docker container ls | show all running containers
docker container ls -a | show all containers regardless of state
docker container ls --filter "status=exited" --filter "ancestor=ubuntu" | show all container instances of the ubuntu image that have exited
docker container inspect [container-name] | display detailed information about specified container
docker container inspect --format '{{.NetworkSettings.IPAddress}}' [container-name] | display detailed information about specified container using specified format
docker container inspect --format '{{json .NetworkSettings}}' [container-name] | display detailed information about specified container using specified format


#### Run Container


Command | Description
--- | ---
docker container run [image-name] | run container based on specified image
docker container run --rm [image-name] | run container based on specified imaged and immediately remove it once it stops
docker container run --name fuzzy-box [image-name] | assign name and run container based on specified image


#### Remove Container


Command | Description
--- | ---
docker container rm [container-name] | remove specified container
docker container rm $(docker container ls --filter "status=exited" --filter "ancestor=ubuntu" -q) | remove all containers whose id's are returned from *'$(...)'* list


### Manage Volumes


#### Display Volume Information


Command | Description
--- | ---
docker volume ls | show all volumes
docker volume ls --filter "dangling=true" | display all volumes not referenced by any containers
docker volume inspect [volume-name] | display detailed information on *[volume-name]*


#### Remove Volumes


Command | Description
--- | ---
docker volume rm [volume-name] | remove specified volume
docker volume rm $(docker volume ls --filter "dangling=true" -q) | remove all volumes having an id equal to any of the id's returned from *'$(...)'* list


---


## Running containers


### Run hello-world container


```docker
docker run hello-world
```


### Run an [Alpine Linux] container (a lightweight linux distribution)


1. Find image and display brief summary


? ?```docker
? ?docker search alpine --filter=stars=1000 --no-trunc
? ?```


1. Fetch alpine image from Docker registry and save it


? ?```docker
? ?docker pull alpine
? ?```


1. Display list of local images


? ?```docker
? ?docker image ls
? ?```


1. List container contents using _listing_ format


? ?```docker
? ?docker run alpine ls -l
? ?```


1. Print message from container


? ?```docker
? ?docker run alpine echo "Hello from Alpine!"
? ?```


1. Running the run command with the -it flags attaches container to an interactive tty


? ?```docker
? ?docker run -it alpine bin/sh
? ?```


### Run MongoDB


#### Run MongoDB Using Named Volume


To run a new MongoDB container, execute the following command from the CLI:


```docker
docker run --rm --name mongo-dev -v mongo-dev-db:/data/db -d mongo
```


CLI Command | Description
--- | ---
--rm | remove container when stopped
--name mongo-dev | give container a custom name
-v mongo-dev-db/data/db | map the container volume 'data/db' to a custom name 'mongo-dev-db'
-d mongo | run mongo container as a daemon in the background


#### Run MongoDB Using Bind Mount


```bash
cd
mkdir -p mongodb/data/db
docker run --rm --name mongo-dev -v ~/mongodb/data/db:/data/db -d mongo
```


CLI Command | Description
--- | ---
--rm | remove container when stopped
--name mongo-dev | give container a custom name
-v ~/mongodb/data/db/data/db | map the container volume 'data/db' to a bind mount '~/mongodb/data/db'
-d mongo | run mongo container as a daemon in the background


### Access MongoDB


#### Connect to MongoDb


There are 2 steps to accessing the MongoDB shell.


1. Firstly, access the MongoDB container shell by executing the following command:


? ?```bash
? ?docker exec -it mongo-dev bash
? ?```


? ?This will open an interactive shell (bash) on the MongoDB container.


1. Secondly, once inside the container shell, access the MongoDB shell by executing the following command:


? ?```bash
? ?mongo localhost
? ?```


#### Show Databases


Once connected to MongoDB shell, run the following command to show a list of databases:


```bash
show dbs
```


#### Create New Database


Create a new database and collection


```javascript
use test
db.messages.insert({"message": "Hello World!"})
db.messages.find()
```


---


## Creating Images


### Create custom [Alpine Linux] image with GIT setup


1. Create project folder with empty Dockerfile


? ?```bash
? ?cd ~
? ?mkdir -p projects/docker/alpine-git
? ?cd !$
? ?touch Dockerfile
? ?```


1. Create Dockerfile


? ?```docker
? ?FROM alpine:latest


? ?LABEL author="codesaucerer" \
? ? ? ? ?description="Official Alpine image with GIT and VIM installed"


? ?ENV WORKING_DIRECTORY=/projects


? ?RUN apk update && apk add git vim


? ?RUN mkdir $WORKING_DIRECTORY


? ?WORKDIR $WORKING_DIRECTORY
? ?```


1. Build Dockerfile


? ?```bash
? ?docker image build -t [docker-username]/alpine-git
? ?docker run --rm -it [docker-username]/alpine-git /bin/sh
? ?```


1. Push Dockerfile


? ?```bash
? ?docker login
? ?docker push [docker-username]/alpine-git:latest
? ?```


---


[Docker]:https://docs.docker.com/engine/installation/
[free training]: https://training.docker.com
[repository]: https://hubs.docker.com
[Alpine Linux]: https://www.alpinelinux.org/