Recently, I’ve got started with writing some Jenkins pipeline code. Groovy, eh? Yep, definitely Groovy. So here I go a-searching for information on Groovy, and here are some of my notes on the things I needed to use.
Use findFiles() in Jenkins to get a list of files in the indicated
directory, matching the given regular expression. Please note that
directories cannot be matched and returned in the file list, only
regular files.
20190531/DuckDuckGo jenkins findFiles
20190531/https://jenkins.io/doc/pipeline/steps/pipeline-utility-steps/
20190531/Google Jenkins findFiles does not list directories
20190531/https://groups.google.com/forum/#!topic/jenkinsci-users/VW_5fiq-6tU
findFiles returns a list of FileWrapper objects, which you must
parse and process to convert into a list of filename strings.
20190531/Google javadoc FileWrapper
20190531/https://javadoc.jenkins.io/plugin/pipeline-utility-steps/org/jenkinsci/plugins/pipeline/utility/steps/fs/FileWrapper.html
Use for-each syntax in Groovy like this:
def result = []
def wrap = findFiles(glob: '*')
wrap.each { it, i // iterator, index
def full_path = it.getPath()
result.add(full_path)
}
If you do not specify the iterator and index variable, it is used by
default for the iterator, and nothing is used for the index, as I
understand it. You can also specify only a name for the iterator
variable.
20190531/DuckDuckGo groovy iterate over a list
20190531/http://riptutorial.com/groovy/example/18003/iterate-over-a-collection
20190531/https://stackoverflow.com/questions/9522897/groovy-how-to-iterate-a-list-with-an-index
20190531/DuckDuckGo groovy for each
20190531/http://docs.groovy-lang.org/latest/html/documentation/index.html#_looping_structures
- Notes on using groovy regular expressions
Groovy regular expression matching can be done using the familiar =~
operator as follows:
def m = text =~ /match/
20190531/DuckDuckGo groovy regex match
20190531/http://docs.groovy-lang.org/latest/html/documentation/index.html#_regular_expression_operators
Note that you must use def to limit the scope of match variables.
If you do not use it, you may get weird errors like “matcher not
serializable.”
20190531/DuckDuckGo jenkins regex matcher not serializable
20190531/https://stackoverflow.com/questions/50855961/notserializableexception-in-jenkinsfile
You can index parenthetical groupings using match variables. For example, to index the third parenthetical grouping, use the following syntax.
m[0][3]
20190531/DuckDuckGo groovy matcher
20190531/https://docs.groovy-lang.org/latest/html/groovy-jdk/java/util/regex/Matcher.html