I am using docker
Docker for mac: Version 1.12.5 (14777)

When i try to follow: https://hub.docker.com/r/jenkinsci/pipeline-as-code-github-demo/
I got following error:

+ docker inspect -f . golang:1.5.0
/var/jenkins_home/workspace/test@tmp/durable-f207891f/script.sh: 2: /var/jenkins_home/workspace/test@tmp/durable-f207891f/script.sh: docker: not found
[Pipeline] sh
[test] Running shell script
+ docker pull golang:1.5.0
/var/jenkins_home/workspace/test@tmp/durable-6490374a/script.sh: 2: /var/jenkins_home/workspace/test@tmp/durable-6490374a/script.sh: docker: not found