johnpfeiffer

Docker Intro install run and port forward

Docker is a union file system based layer system (previously leveraging linux lxc containers) for ultra lightweight virtualization/compartmentalization.

Much like AWS cloud servers (api based dynamic deployment that should be tolerant of node failure) and automated deployment/configuration infrastructure (chef or puppet such that cloud servers are created idempotent, remotely and automatically managed at scale), Docker requires a change of mindset.

Docker encourages design of modular, deterministic and defined, single purpose components that are easy to compose into larger services.

As any tool, using it for managing complexity and packaging can be very helpful but it does expose other potential issues (composability, orchestration, security).

Install Docker

https://docs.docker.com/engine/installation/linux/ubuntulinux/

  1. apt-key adv --keyserver hkp://pgp.mit.edu:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D
  2. sudo sh -c "echo 'deb https://apt.dockerproject.org/repo ubuntu-trusty main' > /etc/apt/sources.list.d/docker.list"
  3. sudo apt-get update
  4. apt-get install linux-image-extra-$(uname -r)
  5. apt-get install docker-engine
  6. service docker status
  7. docker info

Make sure it lists /var/lib/docker/aufs

OPTIONAL STEP IF YOU HAD AN OLD DOCKER INSTALLATION apt-get purge lxc-docker*

Installing on Mac or Windows

https://www.docker.com/docker-toolbox

Custom docker0 ip range

Fixing the Docker Bridge docker0 taking a huge 172.17.0.1/16 address space...

Private IP address space is not normally a thing to worry about, unless someone does something silly and grabs 65,534 addresses (stare) (docker)

Because the default docker0 bridge seems to cater to organizations that want to run thousands of containers simultaneously local developers need to do the following fix:

  1. apt-get install bridge-utils
  2. service docker stop
  3. ip link set docker0 down
  4. brctl delbr docker0
  5. docker daemon --bip=192.168.239.1/24
  6. ifconfig

Docker will be running interactively so you can see all the fun log messages

You should see docker0 "inet addr:192.168.239.1 Bcast:0.0.0.0 Mask:255.255.255.0"

Assuming you do not have some other purpose for the 192.168.239 range in which case you can change it to something else

To permanently have this custom ip range configuration for docker (assuming you have done the steps above):

  1. Control + C to quit the previously interactive docker daemon
  2. vi /etc/default/docker
  3. DOCKER_OPTS="--bip=192.168.239.1/24"
  4. service docker start
  5. ifconfig

You should see docker0 "inet addr:192.168.239.1 Bcast:0.0.0.0 Mask:255.255.255.0"

More docs to further troubleshoot the docker0 bridge...

Quick Start Summary

docker run --rm busybox /bin/sh -c "echo 'hi'"
hi

docker run -it --rm -e MYVAR=123 busybox env

"run" will pull the image from Docker Hub by default, e injects an environment variable, overrides the Docker Image CMD with "env"

docker run -it --rm --entrypoint=/bin/sh python:latest

Download a docker image

Official Images are he easiest to experiment with: https://hub.docker.com/explore/

sudo docker pull ubuntu:trusty

(grabs the latest, i.e. 14.04.1) or use a different tag to download a more specific version sudo docker pull ubuntu:12.04.3

CRITICAL WARNING! use the colon and a specific version! downloading all of the ubuntu images by accident sucks =(

sudo docker pull redis:latest

choose the latest for just messing around but... ALWAYS use a specific version to avoid having your dependencies change unexpectedly

Finding what versions of images (tags) you can pull requires using either the UI or the API:

Many of the tags are synonyms/symlinks, so latest is the same as 3 is the same as 3.0

Remove a docker image

docker rmi redis

docker rmi -f $(docker images --all --quiet | grep -v 5506de2b643b)

remove ALL images except one by taking the output (quiet means only image ids), excluding a specific one, and then force removing the images (by id)

docker images --quiet --filter "dangling=true" | xargs docker rmi

remove all images that do not have a tag and are not a parent of a tagged image

docker rmi -f $(docker images --all --quiet)

remove ALL images

du -sh /var/lib/docker/aufs

Summarize the amount of disk space taken by images and layers, e.g.: 72K /var/lib/docker/aufs/

Sometimes a docker image is still connected to a container (already exited or forgotten)

docker ps -a
docker rm name_or_id

docker rm a1b2
docker rmi image_id

it will "smart match" the first characters of the container ID the same as git short sha

Docker info

docker

get a helpful list of all the commands

docker --version

docker info

:::text
Containers: 1
Images: 23
Storage Driver: aufs
 Root Dir: /var/lib/docker/aufs
 Dirs: 25
Execution Driver: native-0.2
Kernel Version: 3.13.0-35-generic
Operating System: Ubuntu 14.04.1 LTS
WARNING: No swap limit support

du -sh /var/lib/docker/aufs

469M /var/lib/docker/aufs/

docker ps --all

no containers are running yet

docker ps --help

docker images --tree is a deprecated command to view the hashes and sizes of all of the parent images

Controlling Containers

Starting a container from an image

Create a container

First you must create a container from an image:

docker run

get a helpful list of how to run a container

docker run --rm -i -t ubuntu:14.04 /bin/bash

:::text
creates a container
--rm: automatically remove the container when it exits
-i: keep stdin open even if not attached
-t: allocate a tty, attach stdin and stdout
use the ubuntu 14.04 minimal image
Docker automatically gives the container a random name
Runs an interactive bash shell

This will continue to exist in a stopped state once exited (see "docker ps -a")

root@f5878ed6016e:/# cat /etc/issue
root@f5878ed6016e:/# uname -a
root@f5878ed6016e:/# df -h

Control-p then Control-q to detach the tty without exiting the shell

docker ps

docker run --detach --name myapp -p 127.0.0.1:5000:5000 training/webapp python app.py

detached with port 5000 available only to the host and executing the command python with parameter app.py

docker exec myapp ls -ahl

runs the ls command inside the container named "myapp"

  • docker run --rm -i -t --link myhipchat_mariadb_1 mariadb:5 /bin/bash -c "exec mysql --version"
  • docker run --rm -i -t --link myhipchat_mariadb_1:mysql mariadb:5 /bin/bash -c 'exec mysql -h"$MYSQL_PORT_3306_TCP_ADDR" -P"$MYSQL_PORT_3306_TCP_PORT" -uroot -p'

    an Image can contain both the server and client code so run a "client container" to connect to a running server Container

Start (resume) a container

After a container has already been created (which starts it so ironically this is actually a "restart")

docker start --interactive --attach container_id_or_name

Attaching to a running container

docker ps -a 
CONTAINER ID ... STATUS        NAMES
9e0ebf4421dd ... Up 6 seconds  myexample

docker attach 9e0ebf4421dd
docker attach myexample

since the above will expect the container to have /bin/bash it will reuse the instance of shell

sudo docker exec -i -t 9e0ebf4421dd /bin/bash
# ps aux
# exit

instead a new /bin/bash is executed inside creating a second shell - use the exit command to not leave it around

Running a container with admin privileges

If your container requires elevated privileges from the host then you need to provide the extra parameter:

docker run --rm -it --cap-add SYS_NET_ADMIN alpine

Alternatively give it all extended privileges and permissions:

docker run --rm -it --privileged alpine

https://docs.docker.com/engine/reference/run/#runtime-privilege-and-linux-capabilities

Stopping a container

Part of the efficiency in docker is that containers can run in the background automatically

docker run --detach --name myredis redis
docker ps
docker stop myredis

Another efficiency is that a docker container will only run as long as it takes to execute a command (and any changes are not forgotten)

docker run ubuntu:trusty uname -a

this runs the container only as long as it takes to execute the command

docker attach f5878ed6016e

Control + C (now we have exited the container and it will clean itself up)

docker ps -a

spun up another container but only long enough to run the command

CONTAINER ID IMAGE        COMMAND      CREATED      STATUS    PORTS         NAMES
e4b436320442 ubuntu:14.04 -uname -a  3 minutes ago              elegant_engelbart

Copying a file out of a container

docker cp <containerId>:/file/path/within/container /host/path/target

https://docs.docker.com/engine/reference/commandline/cp/

Deleting aka removing a container

docker rm e4b436320442

Alternatively: docker rm --force elegant_engelbart

docker rm -f $(docker ps -a -q)

Deletes forcibly all containers (be careful!)

Dockerfile to automate building an image

Dockerfiles allow automating the creation docker images.

One advantage to Dockerfile is that each command creates a separate layer so if a specific layer fails all of the previous intermediate images can be re-used.

Also the version style of imagename:tag allows for chaining of upgrades of child images

Containers as fast, reliable, and deterministic prod/qa/dev environments can also be extended to be just an improved experimentation sandbox (for those used to SSH and using Linux as a common base OS).

mkdir -p dockerfiles/trustyssh
vi dockerfiles/trustyssh/Dockerfile

one Dockerfile per directory

FROM ubuntu:trusty
MAINTAINER John Pfeiffer "https://bitbucket.org/johnpfeiffer"

RUN apt-get update -y
RUN apt-get install -y openssh-server byobu
RUN mkdir /var/run/sshd
RUN echo 'root:root' | chpasswd
RUN echo 'ubuntu:ubuntu' | chpasswd
RUN sed -ri 's/^PermitRootLogin\s+.*/PermitRootLogin yes/' /etc/ssh/sshd_config
RUN sed -ri 's/UsePAM yes/#UsePAM yes/g' /etc/ssh/sshd_config
EXPOSE 22
CMD    ["/usr/sbin/sshd", "-D"]


docker build --tag=newimagename --rm ./dockerfiles/ubuntu-trusty-ssh

Each RUN command creates an intermediate container, so make sure you use the -rm option

Sending build context to Docker daemon  2.56 kB
Sending build context to Docker daemon
Step 0 : FROM ubuntu:trusty
 ---> 5506de2b643b
...
Removing intermediate container 135b686d82a6
Step 2 : RUN apt-get update -y
 ---> Running in 7fe06a9ef41b
Ign http://archive.ubuntu.com trusty InRelease
...

Since each run command creates a new layer it is best practice to consolidate commands for a single logical action when possible:

RUN echo "#!/bin/bash" > /root/build-and-run.sh && \
  echo "cd /opt/mydata/pelican-project" >> /root/build-and-run.sh && \
  echo "pelican content -r &" >> /root/build-and-run.sh && \
  echo "cd /opt/mydata/pelican-project/output" >> /root/build-and-run.sh && \
  echo "python -m SimpleHTTPServer" >> /root/build-and-run.sh && \
  chmod +x /root/build-and-run.sh


docker history ubuntu-utopic-pelican:latest

view the history of hashes (which can be run by themselves) and timestamps and sizes

IMAGE               CREATED             CREATED BY                                      SIZE
39ac388d3c0d        37 seconds ago      /bin/sh -c #(nop) CMD [/bin/bash /root/build-   0 B
218edf407f18        37 seconds ago      /bin/sh -c echo "#!/bin/bash" > /root/build-a   129 B
d9d774d344bd        2 weeks ago         /bin/sh -c #(nop) EXPOSE 8000/tcp               0 B
ae1733e0e1b9        2 weeks ago         /bin/sh -c pip install pelican Markdown beaut   20.64 MB
24561ed8052f        2 weeks ago         /bin/sh -c curl https://bootstrap.pypa.io/get   9.826 MB
1878a9a052eb        2 weeks ago         /bin/sh -c apt-get update && apt-get install    60.85 MB
5e5e0e9171da        2 weeks ago         /bin/sh -c #(nop) MAINTAINER John Pfeiffer "h   0 B
78949b1e1cfd        7 weeks ago         /bin/sh -c #(nop) CMD [/bin/bash]               0 B
21abcc4ef877        7 weeks ago         /bin/sh -c sed -i 's/^#\s*\(deb.*universe\)$/   1.895 kB
f552c527d701        7 weeks ago         /bin/sh -c echo '#!/bin/sh' > /usr/sbin/polic   215 kB
c4c77a6165f9        7 weeks ago         /bin/sh -c #(nop) ADD file:24ed1895f2e500dcec   194.2 MB
511136ea3c5a        22 months ago                                                       0 B

experimental: docker save 49b5a7a88d5 | sudo docker-squash -t ubuntu-utopic-pelican:squash | docker load

Add a port to a container

docker run --detach --publish 127.0.0.1:2222:22 --name johnssh trustyssh

run a detached container based on the trustyssh image that binds the private container port 22 to the host port 2222 (in this case the trustyssh image from above is running sshd on port 22)

docker port johnssh 22

127.0.0.1:2222

netstat -antp | grep 2222

tcp 0 0 127.0.0.1:2222 0.0.0.0:* LISTEN 24393/docker-proxy

ssh -o StrictHostKeychecking=no -p 2222 [email protected]

root@19ad0614b237:~#

command output
docker run --detach --publish 0.0.0.0:6379:6379 --name redis redis feeb79581810a8c182202c73d4e1c6b905960bcfc860e04285f1ae03c6a47f18
docker port redis 6379/tcp -> 0.0.0.0:6379
docker port redis 6379 0.0.0.0:6379
redis-cli -h docker.example.com ping PONG
docker run --detach --publish-all --name redis redis ff2f6d2e04d565f11d71664bf6cf23638656d9b633e4d3c94444c81b18b807bb
docker port redis 6379/tcp -> 0.0.0.0:49153
docker port redis 6379 0.0.0.0:49153

docker run --detach -P --name johnssh trustyssh

publish all EXPOSE'd ports to random ports on the host

Logs from the containers

docker logs container_name

view the latest logs of a specific container in stdout

docker logs -f container_name

tail the logs for

Host data with a Docker Container

Volumes are where Docker Containers can access storage (either from the Host or other Containers)

https://docs.docker.com/userguide/dockervolumes

docker run --interactive --tty --name mydata --volume /tmp/mydata:/opt/mydata trustyssh /bin/bash

create an interactive container named "mydata" that maps /tmp/mydata from the host onto /opt/mydata (warning: overriding any existing!)

Managing or limiting the resources available to a Container

https://docs.docker.com/engine/reference/run/#runtime-constraints-on-resources

docker run -i -t --rm --cpuset-cpu 0 --memory 512m ubuntu:14.04 /bin/bash

the usual ubuntu trusty bash prompt but anything we run will be pinned to cpu 0 (i.e. 25% of a 4 core system) and have at most 512 MB of RAM and 512 MB of swap available

Using Docker for a GUI application

Mostly outside of the vision of containerization (neither isolation nor performance exactly) is using Docker to run GUI applications without installing them on the Host.

Jessie Frazelle has done some excellent work pointing out how sharing the X11 socket from the host means lots of apps can run "without being installed" https://github.com/jfrazelle/dockerfiles

One tip she did not include was the part about XManager security, run the following if you run into an error

xhost local:root - https://www.netsarang.com/knowledgebase/xmanager/3898/xhost_and_how_to_use_it - http://www.x.org/archive/X11R6.8.0/doc/xhost.1.html

xhost local:root; docker run --rm -v /tmp/.X11-unix:/tmp/.X11-unix -e DISPLAY=unix$DISPLAY --device /dev/snd jess/chromium - modify the xhost security to allow access to x windows - ephemeral so do not save anything - share the X11 unix socket - bind to the current display (i.e. :0.0) - allow sound from the Docker container

Saving a docker container as a new image

docker commit --help

docker commit for a container: ubuntu:trusty with git

  1. docker run -i -t ubuntu:trusty /bin/bash
  2. Control + p then Control + q (to detach the tty without exiting the shell)
  3. docker ps -a (make a note of the ID or NAME)
  4. docker attach ID_OR_NAME
  5. apt-get update; apt-get install git -y
  6. cd /root
  7. git --version
  8. git clone https://[email protected]/johnpfeiffer/myrepo.git
  9. exit
  10. exit

    now the Container will have git installed, a repo cloned, and will be stopped

  11. docker commit container_name_here johnpfeiffer_git_repo

    4a74440186d976caeccc52f5ed2bd44269beb84d472391a7ce26ee3db8ffc1e9

  12. docker images

output

REPOSITORY               TAG                 IMAGE ID            CREATED             VIRTUAL SIZE
johnpfeiffer_git_repo    latest              4a74440186d9        54 seconds ago      402 MB
ubuntu                   14.04               e54ca5efa2e9        3 weeks ago         276.5 MB

Misc

Python and Pelican static site generator on docker ubuntu:14.04

  1. apt-get update; apt-get install python python-setuptools openssl wget -y
  2. wget -qO- https://raw.github.com/pypa/pip/master/contrib/get-pip.py | sudo python
  3. pip install pelican Markdown beautifulsoup4
  4. docker run -i -t -p 127.0.0.1:8000:8000 --name john johnpfeiffer_git_repo:latest /bin/bash
  5. control+p then control+q
  6. docker attach john
  7. cd /root/myrepo
  8. pelican content (assuming pelicanconf.py is here)
  9. cd output
  10. python -m SimpleHTTPServer
  11. control+p then control+q
  12. docker ps -a
  13. http://127.0.0.1:8000

Docker pre built Images from the Registry

Redis

docker search redis

search from the CLI but NAME, DESCRIPTION, STARS, OFFICIAL will only help you if you sort of already know what you are looking for

https://registry.hub.docker.com/_/redis/

docker run --detach --publish 127.0.0.1:6379:6379 --name redis redis

detached container based on the redis latest bound to the host on port 6379

the image already includes by default the expose port command: EXPOSE 6379... apt-get install redis-tools; redis-cli

connect from the host to the redis container to the redis interactive cli

docker run -i -t --link redis:db  johnssh /bin/bash

root@d95a758eaa6b:/#
apt-get install redis-tools
env
redis-cli -h $DB_PORT_6379_TCP_ADDR
ping

PONG

get mykey

"somevalue"

docker stop johnssh

docker start --interactive --attach johnssh

root@d95a758eaa6b:/#

Environment variables are tricky

sudo docker run --detach --publish 127.0.0.1:2222:22 --name johnssh trustyssh

if you SSH into your container or use byobu "env" will not show you the info

**From the host: ** sudo docker inspect --format '{{ .NetworkSettings.IPAddress }}' redis

172.17.0.72

ssh -p 2222 root@localhost
apt-get install redis-tools
redis-cli -h 172.17.0.72 keys *
1) mykey

** Add a route to the Host From inside a Container/Guest **

HOST:

ip addr show
ip addr show | grep docker0
ip addr show | grep docker0 | grep global | awk '{print $2}' | cut -d / -f1
HOSTIP=$(ip addr show | grep docker0 | grep global | awk '{print $2}' | cut -d / -f1)

sudo docker run -i -t --rm --add-host=docker:${HOSTIP} python:2 /bin/bash

root@1bbe25092f19:/# cat /etc/hosts

172.17.0.7      1bbe25092f19
127.0.0.1       localhost
 ::1     localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters

172.17.42.1     docker

root@1bbe25092f19:/# ping docker

PING docker (172.17.42.1): 56 data bytes
64 bytes from 172.17.42.1: icmp_seq=0 ttl=64 time=0.158 ms

https://docs.docker.com/engine/reference/commandline/run/

Docker Compose

Complex real systems have multiple dependencies and following the recommended Docker pattern of "do one thing per container" means needing a way to start/orchestrate a bunch of things at once.

While there are some amazing open source projects (http://kubernetes.io/ , https://mesos.apache.org/documentation/latest/docker-containerizer/) it is instructive to start with the simplest model provided directly from Docker, https://docs.docker.com/compose/

Either download the docker-compose binary directly (to /usr/local/bin): - https://github.com/docker/compose/releases

sudo curl -L "https://github.com/docker/compose/releases/download/1.25.4/docker-compose-$(uname -s)-$(uname -m)" -o /usr/local/bin/docker-compose sudo chmod +x /usr/local/bin/docker-compose

Or use pip/python to install it...

sudo pip install --upgrade docker-compose

which docker-compose ; sudo docker-compose --version

app.py

from flask import Flask
from redis import Redis
import os
app = Flask(__name__)
redis = Redis(host='redis', port=6379)

@app.route('/')
def hello():
    redis.incr('hits')
    return 'Hello World! I have been seen %s times.' % redis.get('hits')

if __name__ == "__main__":
    app.run(host="0.0.0.0", debug=True)

requirements.txt

flask
redis

Dockerfile

FROM python:2.7
ADD . /code
WORKDIR /code
RUN pip install -r requirements.txt
CMD python app.py

docker-compose.yml

web:
  build: .
  ports:
   - "5000:5000"
  volumes:
   - .:/code
  links:
   - redis
redis:
  image: redis
  • dependencies like redis are "linked" for network access (ordering in the file is important)
  • "web" app (which comes from the current directory Dockerfile)
  • ports: exposes ports to the host (all of these are just like the docker run CLI parameters)
  • volumes: allows live editing of app.py
  • redis comes from the public docker registry image (not a Dockerfile nor a private registry) and is using the default tag of "latest"

docker-compose up

docker-compose up

this will docker pull redis and build from the Dockerfile and then start them all in the correct order

docker-compose ps

run this command in the directory with the docker-compose.yml to see the state of the system

         Name                      Command             State           Ports          
-------------------------------------------------------------------------------------
composeexample_redis_1   /entrypoint.sh redis-server   Up      6379/tcp               
composeexample_web_1     /bin/sh -c python app.py      Up      0.0.0.0:5000->5000/tcp

docker ps -a

docker-compose stop

http://localhost:5000/

Hello World! I have been seen 2 times.

https://bitbucket.org/johnpfeiffer/docker/src

Troubleshooting

Building images with Dockerfile

Building images often depends on the network and DNS

If you are using Wifi be careful as intermittent network connectivity may cause frustrating issues.

For DNS with docker installed onto ubuntu via apt-get, try changing to Google DNS by uncommenting in:

vi /etc/default/docker

sudo service docker restart

Building images often depends on dependencies look closely at error messages, i.e. make: not found and ensure that an early RUN statement has apt-get update && apt-get install -y build-essential

Discovering an Image Parent from History

To see all of the images in detail: docker images --all --digests=true

python      2.7-alpine      sha256:834b44717d3928266472066d82208241a2582ce7b3787f32abbfb0def9fb0324   c80455665c57        6 weeks ago         71.49 MB
alpine      latest          sha256:dfbd4a3a8ebca874ebd2474f044a0b33600d4523d03b0df76e5c5986cb02d7e8   88e169ea8f46        6 weeks ago         3.984 MB

And then you can brute force query to see if an image has child dependencies:

for i in $(docker images -q); do docker history $i | grep -q 7fb9bd20d612 && echo $i; done

More Info

Docker API and the Docker Hub Public Registry

Docker used to have an API endpoint at registry.hub.docker.com/v1 but in a fairly typical move for them they changed it so a lot of internet "documentation" examples are wrong.

Also the Docker Hub was deprecated as of 1.7 so this is the last docs on how to use it (because the service is still running or compatible)

curl https://index.docker.io/v1/_ping
true

It uses basic authentication and while you can use the API to sign up it may just be easier to use the web site: https://hub.docker.com/

curl https://username:password@index.docker.io/v1/users/
"OK"

just curl with basic auth in order to check the credentials, the trailing slash is IMPORTANT

Using a browser with the Docker REST API is often more convenient as it caches the Basic Authentication

To see all of the images for a given repository (it is json formatted and there will be a lot of results!) curl https://username:[email protected]/v1/repositories/python/images

https://docs.docker.com/v1.6/reference/api/registry_api/

If you docker search python and want to see the tags (i.e. you do not want to pull every python image ever made), then try curl with REST:

curl https://username:password@index.docker.io/v1/repositories/python/tags

[{"layer": "a2db1214", "name": "latest"}, {"layer": "edb21ec7", "name": "2"}, {"layer": "82b600dd", "name": "2-alpine"}, {"layer": "6a4e9662", "name": "2-onbuild"}, {"layer": "99b38a11", "name": "2-slim"}, {"layer": "fe724fa0", "name": "2-wheezy"}, {"layer": "edb21ec7", "name": "2.7"}, {"layer": "82b600dd", "name": "2.7-alpine"}, {"layer": "6a4e9662", "name": "2.7-onbuild"}, {"layer": "99b38a11", "name": "2.7-slim"}, {"layer": "fe724fa0", "name": "2.7-wheezy"}, {"layer": "c71c2739", "name": "2.7.10"}, {"layer": "f1f35fa4", "name": "2.7.10-onbuild"}, {"layer": "843123ac", "name": "2.7.10-slim"}, {"layer": "fde41dc3", "name": "2.7.10-wheezy"}, {"layer": "edb21ec7", "name": "2.7.11"}, {"layer": "82b600dd", "name": "2.7.11-alpine"}, {"layer": "6a4e9662", "name": "2.7.11-onbuild"}, {"layer": "99b38a11", "name": "2.7.11-slim"}, {"layer": "fe724fa0", "name": "2.7.11-wheezy"}, {"layer": "a87a2288", "name": "2.7.7"}, {"layer": "481b175a", "name": "2.7.8"}, {"layer": "fbb30ed2", "name": "2.7.8-onbuild"}, {"layer": "3cf7f142", "name": "2.7.8-slim"}, {"layer": "6a873836", "name": "2.7.8-wheezy"}, {"layer": "2d0d0130", "name": "2.7.9"}, {"layer": "10948f7c", "name": "2.7.9-onbuild"}, {"layer": "e86252d0", "name": "2.7.9-slim"}, {"layer": "a11d441b", "name": "2.7.9-wheezy"}, {"layer": "a2db1214", "name": "3"}, {"layer": "bb6cd371", "name": "3-alpine"}, {"layer": "80662aa6", "name": "3-onbuild"}, {"layer": "07bfefb9", "name": "3-slim"}, {"layer": "2edf9614", "name": "3-wheezy"}, {"layer": "7575f4a5", "name": "3.2"}, {"layer": "31b273f6", "name": "3.2-onbuild"}, {"layer": "ca0a0ed6", "name": "3.2-slim"}, {"layer": "f5644650", "name": "3.2-wheezy"}, {"layer": "7575f4a5", "name": "3.2.6"}, {"layer": "31b273f6", "name": "3.2.6-onbuild"}, {"layer": "ca0a0ed6", "name": "3.2.6-slim"}, {"layer": "f5644650", "name": "3.2.6-wheezy"}, {"layer": "84717b99", "name": "3.3"}, {"layer": "4de0c1a0", "name": "3.3-alpine"}, {"layer": "e0985e72", "name": "3.3-onbuild"}, {"layer": "3c0f39af", "name": "3.3-slim"}, {"layer": "a13ad718", "name": "3.3-wheezy"}, {"layer": "e663e96e", "name": "3.3.5"}, {"layer": "79d3367e", "name": "3.3.5-onbuild"}, {"layer": "84717b99", "name": "3.3.6"}, {"layer": "4de0c1a0", "name": "3.3.6-alpine"}, {"layer": "e0985e72", "name": "3.3.6-onbuild"}, {"layer": "3c0f39af", "name": "3.3.6-slim"}, {"layer": "a13ad718", "name": "3.3.6-wheezy"}, {"layer": "c7184f4f", "name": "3.4"}, {"layer": "e6310f15", "name": "3.4-alpine"}, {"layer": "c38d9f7b", "name": "3.4-onbuild"}, {"layer": "ab9f7f65", "name": "3.4-slim"}, {"layer": "c98c4a9d", "name": "3.4-wheezy"}, {"layer": "b504e00c", "name": "3.4.1"}, {"layer": "07e5901a", "name": "3.4.1-onbuild"}, {"layer": "ec50e6a0", "name": "3.4.2"}, {"layer": "ade8543e", "name": "3.4.2-onbuild"}, {"layer": "dd1dee45", "name": "3.4.2-slim"}, {"layer": "de6911d6", "name": "3.4.2-wheezy"}, {"layer": "48bc52cc", "name": "3.4.3"}, {"layer": "bf599bc6", "name": "3.4.3-onbuild"}, {"layer": "0b92f173", "name": "3.4.3-slim"}, {"layer": "b8845e5b", "name": "3.4.3-wheezy"}, {"layer": "c7184f4f", "name": "3.4.4"}, {"layer": "e6310f15", "name": "3.4.4-alpine"}, {"layer": "c38d9f7b", "name": "3.4.4-onbuild"}, {"layer": "ab9f7f65", "name": "3.4.4-slim"}, {"layer": "c98c4a9d", "name": "3.4.4-wheezy"}, {"layer": "a2db1214", "name": "3.5"}, {"layer": "bb6cd371", "name": "3.5-alpine"}, {"layer": "80662aa6", "name": "3.5-onbuild"}, {"layer": "07bfefb9", "name": "3.5-slim"}, {"layer": "c64596cb", "name": "3.5.0"}, {"layer": "c9744d7e", "name": "3.5.0-onbuild"}, {"layer": "ac60c7d8", "name": "3.5.0-slim"}, {"layer": "31ef8f64", "name": "3.5.0b3"}, {"layer": "7c5e081c", "name": "3.5.0b3-onbuild"}, {"layer": "0c47d2de", "name": "3.5.0b3-slim"}, {"layer": "a2db1214", "name": "3.5.1"}, {"layer": "bb6cd371", "name": "3.5.1-alpine"}, {"layer": "80662aa6", "name": "3.5.1-onbuild"}, {"layer": "07bfefb9", "name": "3.5.1-slim"}, {"layer": "bb6cd371", "name": "alpine"}, {"layer": "80662aa6", "name": "onbuild"}, {"layer": "07bfefb9", "name": "slim"}, {"layer": "2edf9614", "name": "wheezy"}]

Docker Engine internal API

If instead of the docker client you wish to interact more programatically...

Private Docker Registry

Login to a private docker registry

curl -i https://username:password@docker.example.com/v2/

attempt to login to a private registry

** Using the docker client to login to a private registry **

docker login docker.example.com:443
> Username: user@example.com
> WARNING: login credentials saved in /home/USER/.docker/config.json
> Login Succeeded

private registry basics via the browser

How to deploy your own docker registry: https://docs.docker.com/registry/deploying/

https://docker.example.com/_ping

{}

https://docker.example.com/info
https://docker.example.com/version

note these commands may not be enabled or available in your private registry version 

https://docker.example.com/v1/repositories/library/ubuntu/tags

{"13.04": "5e47ac691989afcd10285ea4e67b46bc0fdc98d90844e57a6d4221c1e3ab4388"}

https://docker.example.com/v1/repositories/micros/baseimage-ubuntu/tags

{"latest": "5a14c1498ff4983793f6e5eddd16868dbad257195f0e85c66ece94d881ecb28f"}

https://docker.example.com/v1/repositories/micros/baseimage-ubuntu/images

list of the images available: [{"id":"8254ff58b098b72425854555204171352a69f5427ba83dee4642ba45d301d0b1"}]

https://docker.example.com/v1/repositories/micros/baseimage-ubuntu/json

inspect an image (what OS, kernel, etc.) {"arch": "amd64", "docker_go_version": "go1.3.3", "docker_version": "1.3.3", "kernel": "3.16.7-tinycore64", "last_update": 1426041024, "os": "linux"}

https://docker.example.com/v1/repositories/myuser/nginx/0348bf1e7cc54327b8c9ce8407c5b3eadade1ef1771d642d08ae16a6aad5bed5/json

inspect a very specific image (by id)

Searching a private docker registry

https://registry.hub.docker.com/v1/search?q=pfeiffer

the public docker registry search query, deprecated in APIv2 so no longer functional

docker search docker.example.com/myuser

the cli command returns a listing of all of the images for a user, deprecated in APIv2 so no longer functional

If there is a proxy in front: docker search user:[email protected]/myuser

curl -s -X GET https://user:password@docker.example.com/v1/search

LIST ALL IMAGES: or use a browser https://docker.example.com/v1/search

curl -X GET https://user:password@docker.example.com/v1/search?q=ubuntu

https://docker.example.com/v1/search?q=ubuntu {"num_results": 4, "query": "ubuntu", "results": [{"description": null, "name": "example/ubuntu"}, {"description": null, "name": "library/ubuntu"}, {"description": null, "name": "micros/baseimage-ubuntu-ansible"}, {"description": null, "name": "micros/baseimage-ubuntu"}]}

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