The purpose of the plugin is to allow writing tasks in go.cd as Groovy scripts. For instance:
shell.run "./gradlew clean #{sourceBuildTasks} -PcurrentVersion=${new Date().format('yyMMddHHmmss')}"
The env binding exposes environment variables passed to the task by go.cd. The following example illustrates accessing 'DEPLOYMENT_HOST' variable:
shell.run "ssh deployuser@${env.DEPLOYMENT_HOST} 'git reset --hard origin/master && git clean -f && git pull'"
There are two bindings to run shell commands:
shell.runshell.runNicely
The first option will fail the task script if the command exits with a code other than 0. The second option does not fail the script implicitly.
Both options return the command exit code. This makes shell.run a short-hand for conveniently running commands whereas shell.runNicely allows more control over exit code handling.
Both run and runNicely accept either one or two parameters, the first one being the command to run. The single-parameter option will redirect shell command output to go.cd console; the double-parameter option treats the second parameter as a closure to call with each line of command output.
Finally, a call to fail will terminate the script:
if (0 != shell.runNicely('the command'))
fail 'Unexpected command output' // fail() can also be called without the message
Shell commands as described above are always executed in the pipeline working directory. When explicit access to working directory is needed, workingDir can be used:
println(new File(workingDir, 'file-name.txt').text)