docker client env setup on windows

Table of Content

Docker Toolbox for Windows is nice toolbox, make docker dev/test possible on windows and Mac OSX.

It includes:

docker-machine to create and operate docker machine which is linux vm within virtualbox, vmware, aws ec2
docker client to run docker command outside vm docker server

The main benefit to run docker client for me, it is easy to integrate docker return result with local win docker control host.

start docker machine

This is how to start docker machine manually:

$ docker-machine start cygdemo 
$ docker-machine env cygdemo
$ docker-machine status cygdemo 
running 
$ docker-machine ip cygdemo  
10.0.10.100

connection error

however you will hit issue with docker client connection error like this:

$ docker ps -a
An error occurred trying to connect: Get http://%2F%2F.%2Fpipe%2Fdocker_engine/v1.24/containers/json?all=1: open //./pipe/docker_engine: The system cannot find the file specified.

$ docker info
An error occurred trying to connect: Get http://%2F%2F.%2Fpipe%2Fdocker_engine/v1.24/info: open //./pipe/docker_engine: The system cannot find the file specified.

You verify docker-machine ssh is working but cannot ping to docker server vm ip.

troubleshooting

If you search from Internet, there are huge amount of misleading info for this, will suggest to remove Host-Only network driver from virtualbox, reinstall docker toolbox, finally I found out the real cause for my case.

$ docker-machine env cygdemo
export DOCKER_TLS_VERIFY="1"
export DOCKER_HOST="tcp://10.0.10.100:2376"
export DOCKER_CERT_PATH="C:\Users\\.docker\machine\machines\cygdemo"
export DOCKER_MACHINE_NAME="cygdemo"
# Run this command to configure your shell:
# eval $("L:\portabledevops\cygwin64\usr\local\bin\docker-machine.exe" env cygdemo)

docker-machine env only display instead of run the env command!

$ docker-machine env --help
Usage: docker-machine env [OPTIONS] [arg...]

Display the commands to set up the environment for the Docker client

dm env setup

The correct way is using eval:

eval $(docker-machine env cygdemo)

you can verify exported env:

$ env|grep DOCKER
DOCKER_HOST=tcp://10.0.10.100:2376
DOCKER_MACHINE_NAME=cygdemo
DOCKER_TLS_VERIFY=1
DOCKER_CERT_PATH=C:\Users\\.docker\machine\machines\cygdemo

$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

denv function

I use script function to simply this work:

alias dm=/usr/local/bin/docker-machine.exe
denv(){
	eval $(docker-machine env "$@")
}
export -f denv

you can enable env like this:

$ denv cygdemo

verify by

$ dm ls
NAME      ACTIVE   DRIVER       STATE     URL                      SWARM   DOCKER    ERRORS
cygdemo   *        virtualbox   Running   tcp://10.0.10.100:2376           v1.12.3

* means cygdemo is active docker machine 

$ docker info 

denv only supports one machine, 0 or 2+ will get error as below:

$ denv
Error: No machine name(s) specified and no "default" machine exists.

$ denv a b
Error: Expected one machine name as an argument