docker-machine-testing-for-running-machines.md

Tutorial

Some helpful automation commands to determine machine state

Discovering the current environment

docker-machine env default 

Ensuring that the instance is stopped

docker-machine stop local

Using this as a check (based upon process return code) and doing something upon failure

docker-machine env default || echo "doesn't exist"

Upon failure... Try starting the machine

docker-machine env local || docker-machine start local 

Changing the name to locald - a machine we know does not exist. Check to see if the machine is running by piping docker-machine ls to egrep. We then check the return code.

docker-machine ls | egrep "^locald[^R]*[u]*Running.*" > /dev/null 
echo $?

We can also get that onto a single line and output a message to indicate the state

docker-machine ls | egrep "^locald[^R]*[u]*Running.*" > /dev/null || echo "not running"

cheers Bryan