Install Docker On Ubuntu 14.04

Prerequisite

1. Minimum kernel version uname -r 3.11.0-15-generic

2. Update package information, ensure that APT works with the https method, and that CA certificates are installed. sudo apt-get update sudo apt-get install apt-transport-https ca-certificates

3. Add the new GPG key. sudo apt-key adv --keyserver hkp://p80.pool.sks-keyservers.net:80 --recv-keys 58118E89F3A912897C070ADBF76221572C52609D

4. Open the /etc/apt/sources.list.d/docker.list file in your favorite editor. If the file doesn’t exist, create it. sudo vi /etc/apt/sources.list.d/docker.list

5. Remove any existing entries from the file.

6. Add an entry for your Ubuntu operating system. On Ubuntu Trusty 14.04 (LTS) deb https://apt.dockerproject.org/repo ubuntu-trusty main

7. Save and close the /etc/apt/sources.list.d/docker.list file.

8. Update the APT package index. sudo apt-get update

9. Purge the old repo if it exists. sudo apt-get purge lxc-docker

10. Verify that APT is pulling from the right repository. apt-cache policy docker-engine

11. It is recommended to install the linux-image-extra kernel package. The linux-image-extra package allows you use the aufs storage driver. sudo apt-get update sudo apt-get install linux-image-extra-$(uname -r) sudo apt-get install apparmor

#Docker Install

1. Update your APT package index. sudo apt-get update

2. Install Docker. sudo apt-get install docker-engine

3. Start the docker daemon. sudo service docker start

4. Verify docker is installed correctly. sudo docker run hello-world

#Useful extras

1. Run docker without sudo sudo groupadd docker sudo usermod -aG docker ubuntu Logout and login

2. If the DNS is not working inside the container, configure it manually. sudo gedit /etc/NetworkManager/NetworkManager.conf comment out the following line:

• #dns=dnsmasq sudo restart network-manager Now the /etc/resolv.conf should have correct dns addresses. Use these to configure the docker DNS sudo vi /etc/default/docker Uncomment and add these: DOCKER_OPTS="--dns 10.210.225.1 --dns 10.210.225.2 --dns 8.8.8.8 --dns 8.8.4.4" Restart the docker service: sudo service docker restart

3. Install docker-compose sudo pip install docker-compose Reference: https://docs.docker.com/engine/installation/linux/ubuntulinux/

#Useful commands It is easier to configure a Dockerfile for any build related commands and use docker-compose and configure docker-compose.yml version 2 for managing networking , volumes and services. I prefer to use that instead of docker command line commands. Refer to any docker project in the gitlab for sample.

1. System wide docker information docker info

2. List docker images docker images

3. List current active containers. Imagine Container as a process. docker ps

4. List all containers docker ps -a

5. Run a container in interactive mode -i , attach terminal -t, and execute bash. Image hash can be any unique start letters of hash or full hash docker run -i -t <image_hash> /bin/bash

6. Build image from Dockerfile. Command executed from the current directory of Dockerfile docker build . Build image with tag(s) docker build -t reponame:tag -t reponame:lastest docker build -t kromil/hadoop:v1.0 -t kromil/hadoop:latest

7. Kill a running container. docker kill <container_id>

8. Remove a container docker rm <container_id>

9. Remove all containers docker rm $(docker ps -a -q)

10. Remove a image docker rmi <image_id>

11. Remove all images docker rmi $(docker images -q)

12. Open terminal on existing running container docker exec -it <container_id> /bin/bash

13. Execute a container in detached mode. The executed command in the container shouldn't exit after execution, else it will cause container to stop. docker run -d <image_hash> <startup_script_or_command_to_execute>

14. Start , stop or restart container docker start <container_id> docker stop <container_id> docker restart <container_id>

15. It is easier to configure network and assign static ip, hostname , add entries to /etc/hosts for cluster etc using docker-compose.yml . However for some quick tests it can done from docker command line. Create your own network to specify static ip address: docker network create --subnet=172.18.0.0/16 Run the container assigning hostname, network, static ip : docker run -h --net --ip -i -t <imageid_hash> /bin/bash docker-compose commands

16. Build using docker-compose docker-compose build

17. Create container and execute using docker-compose docker-compose up -d

18. Stop, start and restart containers defined in config file without removing them docker-compose stop docker-compose start docker-compose restart

19. Execute any commands in container from outside(host) without getting in. Look at processes running inside a container or tail a log file. docker exec -it <container_id> ps -ef docker exec -it <container_id> tail -f References: https://docs.docker.com/engine/reference/commandline/

#Debugging:

1. ERROR: cannot create network, conflicts with existing network, networks have overlapping IPv4. Remove the existing containers which are currently referencing the network. Turn the bridge down: sudo ip link set <bridge_name> down Delete the bridge: sudo brctl delbr <bridge_name> List the networks: docker network ls Remove the bridge network: docker network rm <bridge_name>