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<center><sup><a href="https://www.docker.com/legal/brand-guidelines">The original Docker logo</a></center>

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I am not a devops engineer means that I am not into the deployment things, however, I want to learn about the Docker. Also I want to utilize it in the development setup on our software team.

Therefore, I have started to learn it from the ground. I will publish my notes about it in the process.


#### General info
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- Unlike the virtualization, Docker has *containerization*. Containers share the same kernel of the host.

- It's much faster and lightweight compared to virtualization.

- Docker has [public images](https://hub.docker.com/) you can download and use. Example: ```docker run centos``` uses the official image centos. If it's not installed in the host, it will download from the docker hub.

- Docker containers exit automatically after running if there is no running process left.

#### Commands
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```docker ps```

Shows the running containers

```docker ps -a```

Shows all containers including the exited ones.

```docker rm <container_id_or_name>```

Removes the container. Tip: You don't need to write IDS full, write a couple of chars from the beginning.

Example:

```
➜  ~ docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                      PORTS               NAMES
b26772f74f32        ubuntu:14.04        "/bin/bash"         3 seconds ago       Exited (0) 14 seconds ago                       xenodochial_hoover
2b8393811355        ubuntu:14.04        "/bin/bash"         6 seconds ago       Exited (0) 17 seconds ago                       determined_agnesi
➜  ~ docker rm 2
2
➜  ~ docker ps -a
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS                      PORTS               NAMES
b26772f74f32        ubuntu:14.04        "/bin/bash"         11 seconds ago      Exited (0) 23 seconds ago                       xenodochial_hoover
```

```docker images```

Shows the installed images

```docker rmi <image>```

Removes the image. If there is a container running based on the image, you need to stop the container first.

```docker pull image```

Pulls the image from docker hub. It can be also ```username/imagename``` for unofficial images. 

```docker stop <container>```

Stops the running container.

```docker run <container> <command>```

Starts a container and runs the command.

Ex: ```docker run ubuntu:14.04 cat /etc/*release*```

Note: if you want to run in detached, use -d param.

```docker exec <container_id> cat /etc/passwd```

Execute commands on running containers.

```docker run -it <image> ```

Creates a container from the image, runs an interactive TTY. (shell)