A Quick Intro to Docker - The Next Big Thing in PaaS

A basic overview and walk-through of Docker functionality.

Presented at the Cloud Computing Atlanta Meetup (http://meetup.com/acloud) on 8/13/13.

Transcript

1. A  Quick  Intro  to  Docker*  
   Chris  Sears  
   Cloud  Compu9ng  Atlanta  Meetup  
   8/13/2013  
    
   *  The  Next  Big  Thing  in  PaaS  
   

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2. PaaS?  
   •  PlaHorm-­‐as-­‐a-­‐Service  
   – PaaS  =>  App-­‐level  abstrac9on  layer  
   – IaaS  =>  VM-­‐level  abstrac9on  layer  
   •  Examples:  
   – Heroku  
   – Google  AppEngine  
   – DotCloud  
   – Cloud  Foundry  
   – OpenShiV  
   

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3. Docker?  
   •  Open  source  app  container  management  tool  
   •  Both  a  standard  and  a  reference  
   implementa9on  
   •  Created  by  DotCloud  
   •  WriYen  in  Go  (golang)  
   •  Uses  advanced  Linux  kernel  features:  
   – LXC,  AUFS,  cgroups,  namespaces  
   

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4. What’s  the  big  idea?    
   •  Create  a  standard  for  “container-­‐izing”  apps  
   •  Make  apps  easy  to  package,  deploy  and  run  
   •  Regardless  of  language,  run9me,  or  backend  
   •  Any  OS,  as  long  as  it’s  Linux  (and  Ubuntu*)  
   *As  of  August  2013.  BusyBox  also  available.  Other  distros  should  be  supported  soon.  
   

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5. Let’s  see  it  in  ac9on…  
    
   (with  help  from  Vagrant)  
   

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6. # Download Docker and Vagrant box
   git clone https://github.com/dotcloud/
   docker.git docker-demo
   cd docker-demo
   

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7. # Boot the Vagrant host, ssh into it,
   # become root, install curl
   vim Vagrantfile
   # add: config.vm.forward_port 5000, 5000
   vagrant up
   vagrant ssh
   sudo su -
   apt-get install curl
   

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8. # Download an Ubuntu image
   # Launch 'Hello World' example container
   docker pull ubuntu
   docker run ubuntu /bin/echo hello world
   # Check hostname inside the container
   docker run ubuntu hostname
   hostname
   

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9. # Launch an interactive bash prompt
   docker run -i -t ubuntu /bin/bash
   docker run -i -t ubuntu /bin/bash
   hostname
   cd /tmp
   echo foo > bar
   exit
   ls /tmp
   

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10. # Launch an interactive bash prompt
    docker run -i -t ubuntu /bin/bash
    # If you see an error, ignore and retry…
    docker run -i -t ubuntu /bin/bash
    hostname
    # Try writing to container file system
    echo foo > /tmp/bar
    ls –la /tmp
    exit
    # Verify /tmp/bar doesn’t exist in host FS
    ls –la /tmp
    

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11. # Launch 'Hello World Loop' example
    CONTAINER_ID=$(docker run -d ubuntu /bin/sh
    -c "while true; do echo hello world
    at...; date; sleep 1; done")
    echo $CONTAINER_ID
    docker logs $CONTAINER_ID
    docker attach $CONTAINER_ID
    docker ps
    docker stop $CONTAINER_ID
    docker ps
    

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12. # Launch a Python Web App example
    docker pull shykes/pybuilder
    URL=http://github.com/shykes/helloflask/
    archive/master.tar.gz
    BUILD_JOB=$(docker run -d -t shykes/
    pybuilder:latest /usr/local/bin/
    buildapp $URL); docker attach
    $BUILD_JOB
    BUILD_IMG=$(docker commit $BUILD_JOB demo)
    WEB_WORKER=$(docker run -d -p :5000
    $BUILD_IMG /usr/local/bin/runapp)
    curl http://127.0.0.1:5000
    # go to http://127.0.0.1:5000 in browser
    

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13. (Assuming  that  all  worked)  
     
     
    Hooray,  it  worked!  
     
     
    

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14. Friends  of  Docker  
    Deis   deis.io  
    Flynn   flynn.io  
    Dokku   github.com/progrium/dokku  
    Vagrant   vagrantup.com  
    OpenStack   github.com/dotcloud/
    openstack-­‐docker  
    

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15. Q  &  A  
    csears  (at)  gmail  (dot)  com  
    @csears  
     
    For  more  Docker:  
    docker.io  
     
    Credit:  Images  and  example  code  were  borrowed  from  
    Docker’s  site  and  excellent  documenta9on.  
     
    

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