Nicola Paolucci!Developer Advocate / Evangelist
with!
Happier Developerwith
Be a
Nicola Paolucci@durdn
Bio pictures: the subtle pleasure of embarrassing yourself in front of hundreds of people
Tools, Tips and Hacks
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3
The plan for this session:
Notes on Workflows and Techniques
1 Why does Docker make Developers happy?
Why?
Compulsion to have clean and perfect
environments
© www.elephantlifestyle.com
the need for speed of every developer with an idea
Fast application mobility, Real repeatability
Great for development team collaboration
Building blocks for your Micro-services Architecture
Micro-services Architecture Blueprint
@crichardson
!!!!!
Traditional Server-side web apps
View Controller
Model
API Gateway
!!!!!
Browser/Native App
View Controller
Model
REST
REST
REST
Product Info Service
Recommendation Service
Review Service
Single entry point
Protocol translationClient specific APIs
Workflows & Techniques
Workflow 1: Develop inside a single running container
As you would in a single VM
Container
Start a shell in container docker run -i -t ubuntu /bin/bash
Folder from host:!/src
Docker host
Host folder!/path/to/code
-v /path/to/code:/src
To use a container as a full Development Environment
phusion/baseimage
Workflow 2: Leverage containers, modularise
Techniques: Embrace Reusability in Dockerfiles
Write general requirements early, commit and name relevant checkpoints, leave customisations last
add + build routine magicTechniques:
docker add <src> <dest>
docker add <src> <dest>The ADD instruction copies new files from host’s <src> to container’s <dest>
docker build your image with updated code
1
2
add + build routine magic?!
Update code in local app folder (git pull?)
Distribute and profit!3
Sharing data in containersTechniques:
Container
Folder from host:!/app
Docker host
Host folder!/opt/test-app
-v /opt/test-app:/app
host to containersshare folder from
host to containers
docker run -v /opt/test-app:/app \ -i -t ubuntu /bin/bash
Use the run -v (volume option) to specify host/container folder to be synced
From
is simple
Same pattern using Dockerfile
FROM busybox VOLUME ["/var/volume1", "/var/volume2"] CMD ["/bin/true"]
Common pattern: Data in containers
Docker host
/var/volume1
DATA
/var/volume2
Common pattern: data in containers
docker run -v /var/volume1 \ -v /var/volume2 \ --name DATA busybox true
Switched off, named, data container which exposes a folder
Data in containers pattern
Docker host
/var/volume1
DATA
/var/volume2
Data in containers pattern
Docker host
/var/volume1
DATA
/var/volume2
/var/volume1
client1
/var/volume2
--volumes-from DATA--volumes-from DATA
Common pattern: data in containers
docker run -t -i -rm --volumes-from DATA \ --name client1 ubuntu bash
Then mount the data container in your application containers
What if you use docker in a VM?
Container
You have an extra layer
Container folder!/src
Docker in a VM
VM folder!/path/to/code
-v /path/to/code:/src
Host OS
Host OS folder!/path/to/code
?
Simplest way: Use Guest Additions
And a VM that supports shared folders. But what if you want to keep using the
lightest weight genius of boot2docker?
boot2docker is great!
Patched boot2docker with vboxsf support
Patched boot2docker with vboxsf support
Pull Request #282-4 add the feature
Patched boot2docker with vboxsf support
https://vagrantcloud.com/dduportal/boot2docker
The UNIX way: NFS, Samba, plan9, etc.
Access via NFS
docker pull cpuguy83/nfs-server
Pull the right image, share a data folder in it, share it with other containers AND the host
docker run -d --name nfs --privileged \ cpuguy83/nfs-server /path/to/share
Access via Samba
docker pull svendowideit/samba
And if you prefer Samba, here’s a shortcut ready made for you
docker run svendowideit/samba data
--links: simple service connections for docker
linked containers
Docker host
/var/volume1
postgresql
/var/volume2
client
--link postgresql:pg
can refer to hostname pg in commands
Sample access to linked container
docker build -t postresql .
Build the image, run it with a name, !link in child container
docker run -rm -P --name pg postgresql
docker run -rm -t -i --link pg:pg postgresql bash !psql -h pg -d docker -U docker --password
Tools, Tips & Hacks
workhorse with a secret weapon
Tiny Core Linux
workhorse with a secret weapon
Tiny Core Aside Awesomeness!
Every time it boots, it is brand-spanking new
Minimal nomadic X desktop for 12MB
Customise your boot2docker/Tiny Core
Tailor the boot sequence in!/opt/bootlocal.sh
List personal settings folders and files !/opt/.filetool.lst
Tunnels, tunnels… and ports
Tunnels and ports
Docker in a VMHost OS
8000 8000
Container
8000 8000
-p outer:inner?
Port forwarding into a container
(boot2docker) ssh -L 8000:localhost:8000
Expose a container port to the host machine
Mass-expose ports with VBoxManage
# vm must be powered off for i in {49000..49900}; do VBoxManage modifyvm "boot2docker-vm" --natpf1 "tcp-port$i,tcp,,$i,,$i"; VBoxManage modifyvm "boot2docker-vm" --natpf1 "udp-port$i,udp,,$i,,$i"; done
To expose all 49XXX ports you can run:
Workarounds section of boot2docker docs
Open ports on live containers with force using iptables
sudo iptables-save
http://j.mp/force-port
Note down the command to open ports of another container
One more thing…
Nicola Paolucci@durdn
Thank you!
