Library to enable scripting in Rendr blueprints

Check out the help text for details on usage:

❯ rendr-sdk-groovy --help

Usage: rendr-sdk-groovy [-hsV] [-v=<key=value>]... <script>
A Groovy script runner for rendr
      <script>              The script file to run.
  -h, --help                Show this help message and exit.
  -s, --stacktrace          Print stacktrace on error.
  -v, --value=<key=value>   Value used in script (flag may be repeated).
  -V, --version             Print version information and exit.

Running a script looks like this:

rendr-sdk-groovy upgrade-v3.groovy --value name=foo --value version=42

Blueprint authors can use this library to simplify creating scripts, especially for blueprint upgrades from one version to the next. The library provides a number of DSL commands:

• create files or directories
• move files or directories
• write text to file
• append text to file
• prepend text to file
• insert text in file
• replace text in file
• git commands
• script for generic Groovy code

Here is a sample script using these DSL commands:

insert 'echo "hi!"' into 'hello.sh' after '#!sh\n'
replace 'hello, world!' with "hello, $name!" inside 'hello.sh'  // references 'name' variable from values flag
git "mv hello.sh ${values.name}.sh"  // this also references 'name', but this time from the 'values' map

create 'hello.log'
git 'add hello.log'

script {
    files = []
    dir('src').eachFileRecurse(FileType.FILES) { file ->
        files << file
    }
    println "All files in src:"
    files.sort().each { println it.path }
}