Jenkins docker:command not found - docker

Question

I have installed Jenkins on my local machine which runs on MacOS High Sierra and have docker installed . I am trying to run a simple pipeline example which uses docker. I have added the following lines to pipeline :
pipeline {
agent {
docker 'node'
}
stages {
stage("testing 123") {
steps {
sh 'node --version'
}
}
}
}
Then from the WebGUI, I click on build now and it is failing. Console output showing the error docker: command not found. The complete error log is as follows :
Started by user Happycoder
Running in Durability level: MAX_SURVIVABILITY
[Pipeline] node
Running on Jenkins in /Users/Shared/Jenkins/Home/workspace/test
[Pipeline] {
[Pipeline] sh
[test] Running shell script
+ docker inspect -f . node
/Users/Shared/Jenkins/Home/workspace/test#tmp/durable-20ded4c0/script.sh: line 2: docker: command not found
[Pipeline] sh
[test] Running shell script
+ docker pull node
/Users/Shared/Jenkins/Home/workspace/test#tmp/durable-ebdc1549/script.sh: line 2: docker: command not found
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
ERROR: script returned exit code 127
Finished: FAILURE
Why this is happening ? In the Jenkins documentation, they are only given this syntax and doesn't mentioned about anything else.

Answer 1

I think the following section is not correct:
agent {
docker 'node'
}
This command will try to launch a Docker container associated with the 'node' label.
If you want to test a declarative pipeline, you should try this syntax (if you want to build a Maven project):
agent {
docker {
image 'maven:3.5.0-jdk-8'
}
}
FYI, you can find a lot of pipeline examples here.