Intro to Docker

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Overview

• What is Docker?
• Getting Started

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What is Docker?

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What is Docker?

“Docker is a full development platform for creating containerized apps”.

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Getting Started

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Download Docker Desktop

1. Go to dockerHub (https://hub.docker.com/).
2. Create an account (https://hub.docker.com/signup).
3. Login with newly created account.
4. Download docker desktop (https://download.docker.com/mac/stable/Docker.dmg).

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Install Docker Desktop

1. Double click on the dmg file downloaded in previous step.
2. Follow the instructions on the wizard to install application.

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Validate Docker Desktop Installation

1. Launch Docker Desktop
2. Login to Docker Desktop
3. Open Terminal
4. Type docker version. You should see information related to the docker installation.
5. Type docker run hello-world. This will download and execute a docker image, thus validating you are able to access docker hub and download images from the the hub.

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#Doing stuff with Docker

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Unit: 1 Containers

###Configuration

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In Terminal, type : docker version

zcw$ docker version 

Client:
    Version: 17.09.0-ce 
    API version: 1.32
    Go version: go1.8.3 
    Git commit: afdb6d4
    Built: Tue Sep 26 22:40:09 2017 
    OS/Arch: darwin/amd64


Server:
    Version: 17.09.0-ce
    API version: 1.32 (minimum version 1.12) 
    Go version: go1.8.3
    Git commit: afdb6d4
    Built: Tue Sep 26 22:45:38 2017

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In Terminal, type : docker info

zcw$ docker info

Containers: 9 
    Running: 0
    Paused: 0 
    Stopped: 9 
    Images: 21
Server Version: 17.09.0-ce 
Storage Driver: overlay2
    Backing Filesystem: extfs
    Supports d_type: true 
Logging Driver: json-file 
Cgroup Driver: cgroupfs
Plugins:
    Volume: local
    Network: bridge host ipvlan macvlan null overlay

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In Terminal, type : docker

zcw$ docker

Management Commands: 
   checkpoint Manage checkpoints
   config Manage Docker configs
   container Manage containers
   image Manage images
   network Manage networks
   node Manage Swarm nodes
   plugin Manage plugins
   secret Manage Docker secrets
   service Manage services
   stack Manage Docker stacks
   ...    

 

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In Terminal, type : docker (continued)

zcw$ docker

Commands: 
   attach   Attach local standard input, output, and error streams to a running container
   build    Build an image from a Dockerfile
   commit   Create a new image from a container's changes
   cp       Copy files/folders between a container and the local filesystem
   create   Create a new container
   deploy   Deploy a new stack or update an existing stack
   diff     Inspect changes to files or directories on a container's filesystem 
   events   Get real time events from the server
   exec     Run a command in a running container
   export 
   history  Export a container's filesystem as a tar archive Show the history of an image
   images List images
 
 
   

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Docker command line structure

Previous versions of docker used :

syntax : docker <mgt-command> (options) 
example: docker run

Newer versions :

syntax : docker <mgt-command> <sub-command> (options) 
example : docker container run

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What we covered

• **Command**: `docker version`
  • Verified cli can talk to engine

• **Command**: `docker info`
  • Most config values of engine

• **Docker command line structure**
  • Old (Still works): `docker (options)`</li>
  • New: `docker (options)`</li> </ul></li></ul> </div> - ## Unit: 1 Containers #### Web Servers - ## Image vs. Container
    • An **image** is the application we want to run
    • A **container** is an instance of that image running as a process
    • You can have many containers running off the same **image**
    • In this unit our **image** will be the **Nginx** server
    • Docker’s default image “registry” is called **Docker Hub** (https://hub.docker.com)
    - ## Let’s start a new container ``` zcw$ docker container run --publish 80:80 nginx ``` ```shell Unable to find image 'nginx:latest' locally latest: Pulling from library/nginx [...] ``` Then, open up your browser of choice and go to http://localhost:80 (refresh your screen a few times and look at the logs)
    • Downloaded **image** ‘nginx’ from **Docker hub**
    • Started a new **container** from that **image**
    - ### Option: `--publish 80:80`
    • Opened port **80** on the host **container** IP
    • Routes that traffic to the **container** IP, port **80**
    - ### Let’s start a new **DETACHED** container ``` zcw$ docker container run --publish 80:80 --detach nginx ``` ```shell b2096a61e9464c2a60bb702545e7d5d4466e0f1f06ea178431d9ff6aec4f8532 ``` Then, open up your browser of choice and go to http://localhost:80 - ### Lets list all of our containers ``` zcw$ docker container ls ``` ```shell CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES b2096a61e946 nginx "nginx -g 'daemon ..." About a minute ago Up About a minute 0.0.0.0:80->80/tcp suspicious_jones``` - ### Let’s stop our containers ``` zcw$ docker container stop b2 ``` ```shell CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES b2096a61e946 nginx "nginx -g 'daemon ..." About a minute ago Up About a minute 0.0.0.0:80->80/tcp suspicious_jones ``` To stop the container, you only have to provide enough of the container id for it to be unique. - ### Let’s list all of our containers ``` zcw$ docker container ls ``` ```shell CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES ``` Since no containers are currently running, none will be listed. - ### Let’s list all of our containers ``` zcw$ docker container ls -a ``` ```shell CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES b2096a61e946 nginx "nginx -g 'daemon ..." 5 minutes ago Exited (0) 2 minutes ago suspicious_jones 1d383263da25 nginx "nginx -g 'daemon ..." 22 minutes ago Exited (0) 5 minutes ago unruffled_mccarthy ``` Adding the `-a` flag will list all the containers, even the ones currently not running. - ### Let’s start a new DETACHED container ``` zcw$ docker container run --publish 80:80 --detach --name ZCW nginx ``` ```shell 83831fe7c024246e2ffb4f6caa0fdf7d7f35d5c632133b4d09908466d44e25cc ``` ``` zcw$ docker container ls ``` ```shell CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 83831fe7c024 nginx "nginx -g 'daemon ..." 33 seconds ago Up 34 seconds 0.0.0.0:80->80/tcp ZCW ``` - ### Let’s look at our logs (Before doing the next step, you will need to refresh a few times on http://localhost:80 to generate logs) ``` zcw$ docker container logs ZCW ``` ```shell 172.17.0.1 - - [13/Dec/2017:22:28:33 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36" "-" 172.17.0.1 - - [13/Dec/2017:22:29:21 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36" "-" 172.17.0.1 - - [13/Dec/2017:22:29:23 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36" "-" 172.17.0.1 - - [13/Dec/2017:22:29:25 +0000] "GET / HTTP/1.1" 304 0 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_13_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/63.0.3239.84 Safari/537.36" "-" ``` - ### Let’s look at our processes ``` zcw$ docker container top ZCW ``` ```shell PID USER TIME COMMAND 15287 root 0:00 nginx: master process nginx -g daemon off; 15315 101 0:00 nginx: worker process ``` - ### Let’s clean up ``` zcw$ docker container ls -a ``` ```shell CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 83831fe7c024 nginx "nginx -g 'daemon ..." 6 minutes ago Up 6 minutes 0.0.0.0:80->80/tcp ZCW b2096a61e946 nginx "nginx -g 'daemon ..." 14 minutes ago Exited (0) 11 minutes ago suspicious_jones 1d383263da25 nginx "nginx -g 'daemon ..." 31 minutes ago Exited (0) 14 minutes ago unruffled_mccarthy ``` ``` zcw$ docker container rm 838 b20 1d3 ``` (Some docker commands can be chained together to do multiple actions) - ### Let’s clean up : We have an error ``` zcw$ docker container rm 838 b20 1d3 ``` ```shell Error response from daemon: You cannot remove a running container 83831fe7c024246e2ffb4f6caa0fdf7d7f35d5c632133b4d09908466d44e25cc. ``` You can not remove a running container , you must either stop the container , or use the `-f` flag to force the removal. `zcw$ docker container rm 838 -f` - ### What happens in ‘docker container run’
    • Looks for the **image** locally in image cache , to see if it's there
    • Then looks in remote **image** repository ( defaults to Docker Hub )
    • Downloads the latest version (Nginx:latest by default)
    • Creates new **container** based on that **image** and prepares to start
    • Gives it a virtual **IP** on a private network inside docker engine
    • Opens up port **80** on host and forwards to port **80** in **container**
    • Start **container** by using the CMD in the image **Dockerfile**
    - ### Example of Changing the Defaults ``` docker container run --publish 8080:80 --name ZCW -d nginx:1.11 nginx -T ```
    • 8080:80 (change host listening port)
    • Nginx:1.11 (change version of image)
    • Nginx -T (change CMD run on start)
    - ### Containers aren’t Mini-VM’s
    • They are just processes
    • Limited to what resources they can access
    • Exit when process stops
    - ### Let’s start up a mongo database ``` zcw$ docker container run --name mongo -d mongo ``` ```shell Unable to find image 'mongo:latest' locally latest: Pulling from library/mongo c4bb02b17bb4: Pull complete 3f58e3bb3be4: Pull complete a229fb575a6e: Pull complete 633f2d5861aa: Pull complete 7f55dbb7ff1d: Pull complete [...] ``` - ### Let’s list out all our running containers ``` zcw$ docker ps ``` ```shell CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 103411b8f3f4 mongo "docker-entrypoint..." 8 minutes ago Up 8 minutes 27017/tcp mongo ``` - ### This is a process on the host ``` zcw$ docker top mongo ``` ```shell USER PID %CPU %MEM VSZ RSS TT STAT STARTED TIME COMMAND 931 0.0 0.1 5117464 23524 ?? S 10:56AM 0:37.56 ``` This is not a VM, this is actually a process on the local system. - ### Let’s list the processes in our containers: ``` $ docker top mongo ``` ```shell PID USER TIME COMMAND 2405 999 0:01 mongod --bind_ip_all ``` - ### Lab: Manage Multiple Containers (Part 1) - http://docs.docker.com and `--help` are your friends - Run a **nginx**, - Run it in `--detach` ( or `-d`), name them with `--name` - **Nginx** should listen on **80:80** - ### Lab: Manage Multiple Containers (Part 2) - http://docs.docker.com and `--help`are your friends - Run a **http**(**apache**) server - Run it `--detach` ( or `-d`), name them with `--name` - **http** should listen on **8080:80** - ### Lab: Manage Multiple Containers (Part 3) - http://docs.docker.com and `--help` are your friends - Run **mysql** - Run it `--detach` ( or -d), name them with `--name` - **Mysql** should listen on **3308:3306** - When running **mysql**, use the `--env` option (or `-e`) to pass in `MYSQL_RANDOM_ROOT_PASSWORD=yes` - Use docker container **logs** on **mysql** to find the random password it created on startup - ### Lab: Manage Multiple Containers (Part 4) - http://docs.docker.com and `--help` are your friends - Clean it all up with `docker container stop` and `docker container rm` (both can accept multiple names of ID’s) - Use `docker container ls` to ensure everything is correct before and after clean up - Next... ## Unit: 1 Containers CLI Monitoring