Jenkins pipeline - how to load a Jenkinsfile without first calling node()? - jenkins

I have a somewhat unique setup where I need to be able to dynamically load Jenkinsfiles that live outside of the src I'm building. The Jenkinsfiles themselves usually call node() and then some build steps. This causes multiple executors to be eaten up unnecessarily because I need to have already called node() in order to use the load step to run a Jenkinsfile, or to execute the groovy if I read the Jenkinsfile as a string and execute it.
What I have in the job UI today:
#Library(value='myGlobalLib#head', changelog=fase) _
node{
load "${JENKINSFILES_ROOT}/${PROJECT_NAME}/Jenkinsfile"
}
The Jenkinsfile that's loaded usually also calls node(). For example:
node('agent-type-foo'){
someBuildFlavor{
buildProperty = "some value unique to this build"
someConfig = ["VALUE1", "VALUE2", "VALUE3"]
runTestTarget = true
}
}
This causes 2 executors to be consumed during the pipeline run. Ideally, I load the Jenkinsfiles without first calling node(), but whenever I try, I get an error message stating:
"Required context class hudson.FilePath is missing
Perhaps you forgot to surround the code with a step that provides this, such as: node"
Is there any way to load a Jenkinsfile or execute groovy without first having hudson.FilePath context? I can't seem to find anything in the doc. I'm at the point where I'm going to preprocess the Jenkinsfiles to remove their initial call to node() and call node() with the value the Jenkinsfile was using, then load the rest of the file, but, that's somewhat too brittle for me to be happy with.

When using load step Jenkins evaluates the file. You can wrap your Jenkinsfile's logics into a function (named run() in my example) so that it will load but not run automatically.
def run() {
node('agent-type-foo'){
someBuildFlavor{
buildProperty = "some value unique to this build"
someConfig = ["VALUE1", "VALUE2", "VALUE3"]
runTestTarget = true
}
}
}
// This return statement is important in the end of Jenkinsfile
return this
Call it from your job script like this:
def jenkinsfile
node{
jenkinsfile = load "${JENKINSFILES_ROOT}/${PROJECT_NAME}/Jenkinsfile"
}
jenkinsfile.run()
This way there is no more nested node blocks because the first gets closed before run() function is called.

Related

How do I use `when` condition on a file's last modified time in Jenkins pipeline syntax

I am creating a Jenkins pipeline, I want certain stage to be triggered only when a particular log file's(log file is located in the server node where all the stages are going to run) last modified date is updated after the initiation of pipeline job, I understand we need to use "When" condition but not really sure how to implement it.
Tried referring some of the pipeline related portals but could not able to find an answer
Can some please help me through this?
Thanks in advance!
To get data about file is quite tricky in a Jenkins pipeline when using the Groovy sandbox since you're not allowed to do new File(...).lastModified. However there is the findFiles step, which basically returns a list of wrapped File objects with a getter for last modified time in millis, so we can use findFiles(glob: "...")[0].lastModified.
The returned array may be empty, so we should rather check on that (see full example below).
The current build start time in millis is accessible via currentBuild.currentBuild.startTimeInMillis.
Now that we git both, we can use them in an expression:
pipeline {
agent any
stages {
stage("create file") {
steps {
touch "testfile.log"
}
}
stage("when file") {
when {
expression {
def files = findFiles(glob: "testfile.log")
files && files[0].lastModified < currentBuild.startTimeInMillis
}
}
steps {
echo "i ran"
}
}
}
}

Start jenkins job immediately after creation by seed job, with parameters?

Start jenkins job immediately after creation by seed job
I can start a job from within the job dsl like this:
queue('my-job')
But how do I start a job with argument or parameters? I want to pass that job some arguments somehow.
Afaik, you can't.
But what you can do is creating it from a pipeline (jobDsl step), then run it. Something more or less like...
pipeline {
stages {
stage('jobs creation') {
steps {
jobDsl targets: 'my_job.dsl',
additionalParameters: [REQUESTED_JOB_NAME: "my_job's_name"]
build job: "my_job's_name",
parameters: [booleanParam(name: 'DRY_RUN', value: true)]
}
}
}
}
With a barebones 'my_job.dsl'...
pipelineJob(REQUESTED_JOB_NAME) {
definition {
// blah...
}
}
NOTE: As you see, I explicitly set the name of the job from the calling pipeline (the REQUESTED_JOB_NAME var) because otherwise I don't know how to make the jobDSL code to return the name of the job it creates back to the calling pipeline.
I use this "trick" to avoid the "job params go one run behind" problem. I use the DRY_RUN param of the job (I use a hidden param, in fact) to run a "do-nothing" build as its name implies, so by the time others need to use the job for "real stuff" its params section has already been properly parsed.

Determine Failed Stage in Jenkins Scripted Pipeline

I am looking for a generic way to determine the name of the failed stage at the end of a Jenkins scripted Pipeline.
Please note that this is different than Determine Failed Stage in Jenkins Declaritive Pipeline which is about declarative pipeline.
Also note that use of try/catch inside each stage is out of question because it would make the pipeline script impossible to read. This is because we have like 10-15 stages which are stored in multiple files and they are compiled using JJB to create the final pipeline script. They are already complex so I need a clean approach on finding which stage failed.
U could also create a custom step in a shared library, a super_stage
Quick example:
// vars/super_stage.groovy
def call(name, body) {
try {
stage(name) {
body()
}
} catch(e) {
register_failed_stage(name, e)
throw e
}
}
In that way you can 'reuse' the same exception handler.
In your scripted pipeline you would then use it like:
super_stage("mystage01") {
//do stuff
}
Source
Use a GraphListener:
def listener = new GraphListener.Synchronous(){
#NonCPS
void onNewHead(FlowNode node){
if (node instanceof StepStartNode){
// before steps execution
}else if (node instanceof StepEndNode){
// after steps execution
}
}
def execution = (FlowExecution) currentBuild.getRawBuild().getExecution()
execution.addListener(listener)
You are going to need a few helper functions in order to make it work, for example StepStartNode and StepEndNode gets called twice so you have to filter the one with the label. Also variables like env are available inside the listener so you can store anything in there to be picked up later.
This answer is pretty generic but I've found that is useful in many of the stackoverflow questions regarding doing something before/after some stage (or in all).
You cannot try/catch exceptions inside the pipeline as this approach is not a wrapper for the stage but just a listener that gets executed once per each line instruction but you can just record the stage at the begining and at the end check currentBuild.result to see if the stage failed. You can do pretty much anything at this point.
At some point with the FlowExecution you have access to the pipeline script, I don't know if it's writtable at that point but it would be awesome to rewrite the pipeline to actually try/catch the stages. If you do something in this line please let me know ;)

Jenkins Pipeline Multiconfiguration Project

Original situation:
I have a job in Jenkins that is running an ant script. I easily managed to test this ant script on more then one software version using a "Multi-configuration project".
This type of project is really cool because it allows me to specify all the versions of the two software that I need (in my case Java and Matlab) an it will run my ant script with all the combinations of my parameters.
Those parameters are then used as string to be concatenated in the definition of the location of the executable to be used by my ant.
example: env.MATLAB_EXE=/usr/local/MATLAB/${MATLAB_VERSION}/bin/matlab
This is working perfectly but now I am migrating this scripts to a pipline version of it.
Pipeline migration:
I managed to implement the same script in a pipeline fashion using the Parametrized pipelines pluin. With this I achieve the point in which I can manually select which version of my software is going to be used if I trigger the build manually and I also found a way to execute this periodically selecting the parameter I want at each run.
This solution seems fairly working however is not really satisfying.
My multi-config project had some feature that this does not:
With more then one parameter I can set to interpolate them and execute each combination
The executions are clearly separated and in build history/build details is easy to recognize which settings hads been used
Just adding a new "possible" value to the parameter is going to spawn the desired executions
Request
So I wonder if there is a better solution to my problem that can satisfy also the point above.
Long story short: is there a way to implement a multi-configuration project in jenkins but using the pipeline technology?
I've seen this and similar questions asked a lot lately, so it seemed that it would be a fun exercise to work this out...
A matrix/multi-config job, visualized in code, would really just be a few nested for loops, one for each axis of parameters.
You could build something fairly simple with some hard coded for loops to loop over a few lists. Or you can get more complicated and do some recursive looping so you don't have to hard code the specific loops.
DISCLAIMER: I do ops much more than I write code. I am also very new to groovy, so this can probably be done more cleanly, and there are probably a lot of groovier things that could be done, but this gets the job done, anyway.
With a little work, this matrixBuilder could be wrapped up in a class so you could pass in a task closure and the axis list and get the task map back. Stick it in a shared library and use it anywhere. It should be pretty easy to add some of the other features from the multiconfiguration jobs, such as filters.
This attempt uses a recursive matrixBuilder function to work through any number of parameter axes and build all the combinations. Then it executes them in parallel (obviously depending on node availability).
/*
All the config axes are defined here
Add as many lists of axes in the axisList as you need.
All combinations will be built
*/
def axisList = [
["ubuntu","rhel","windows","osx"], //agents
["jdk6","jdk7","jdk8"], //tools
["banana","apple","orange","pineapple"] //fruit
]
def tasks = [:]
def comboBuilder
def comboEntry = []
def task = {
// builds and returns the task for each combination
/* Map the entries back to a more readable format
the index will correspond to the position of this axis in axisList[] */
def myAgent = it[0]
def myJdk = it[1]
def myFruit = it[2]
return {
// This is where the important work happens for each combination
node(myAgent) {
println "Executing combination ${it.join('-')}"
def javaHome = tool myJdk
println "Node=${env.NODE_NAME}"
println "Java=${javaHome}"
}
//We won't declare a specific agent this part
node {
println "fruit=${myFruit}"
}
}
}
/*
This is where the magic happens
recursively work through the axisList and build all combinations
*/
comboBuilder = { def axes, int level ->
for ( entry in axes[0] ) {
comboEntry[level] = entry
if (axes.size() > 1 ) {
comboBuilder(axes[1..-1], level + 1)
}
else {
tasks[comboEntry.join("-")] = task(comboEntry.collect())
}
}
}
stage ("Setup") {
node {
println "Initial Setup"
}
}
stage ("Setup Combinations") {
node {
comboBuilder(axisList, 0)
}
}
stage ("Multiconfiguration Parallel Tasks") {
//Run the tasks in parallel
parallel tasks
}
stage("The End") {
node {
echo "That's all folks"
}
}
You can see a more detailed flow of the job at http://localhost:8080/job/multi-configPipeline/[build]/flowGraphTable/ (available under the Pipeline Steps link on the build page.
EDIT:
You can move the stage down into the "task" creation and then see the details of each stage more clearly, but not in a neat matrix like the multi-config job.
...
return {
// This is where the important work happens for each combination
stage ("${it.join('-')}--build") {
node(myAgent) {
println "Executing combination ${it.join('-')}"
def javaHome = tool myJdk
println "Node=${env.NODE_NAME}"
println "Java=${javaHome}"
}
//Node irrelevant for this part
node {
println "fruit=${myFruit}"
}
}
}
...
Or you could wrap each node with their own stage for even more detail.
As I did this, I noticed a bug in my previous code (fixed above now). I was passing the comboEntry reference to the task. I should have sent a copy, because, while the names of the stages were correct, when it actually executed them, the values were, of course, all the last entry encountered. So I changed it to tasks[comboEntry.join("-")] = task(comboEntry.collect()).
I noticed that you can leave the original stage ("Multiconfiguration Parallel Tasks") {} around the execution of the parallel tasks. Technically now you have nested stages. I'm not sure how Jenkins is supposed to handle that, but it doesn't complain. However, the 'parent' stage timing is not inclusive of the parallel stages timing.
I also noticed is that when a new build starts to run, on the "Stage View" of the job, all the previous builds disappear, presumably because the stage names don't all match up. But after the build finishes running, they all match again and the old builds show up again.
And finally, Blue Ocean doesn't seem to vizualize this the same way. It doesn't recognize the "stages" in the parallel processes, only the enclosing stage (if it is present), or "Parallel" if it isn't. And then only shows the individual parallel processes, not the stages within.
Points 1 and 3 are not completely clear to me, but I suspect you just want to use “scripted” rather than “Declarative” Pipeline syntax, in which case you can make your job do whatever you like—anything permitted by matrix project axes and axis filters and much more, including parallel execution. Declarative syntax trades off syntactic simplicity (and friendliness to “round-trip” editing tools and “linters”) for flexibility.
Point 2 is about visualization of the result, rather than execution per se. While this is a complex topic, the usual concrete request which is not already supported by existing visualizations like Blue Ocean is to be able to see test results distinguished by axis combination. This is tracked by JENKINS-27395 and some related issues, with design in progress.

How does variable scoping work when splitting a workflow into smaller chunks?

I have a very long workflow for building and testing our application. So long, in fact, that when we try to load the main workflow script, we get this exception:
java.lang.ClassFormatError: Invalid method Code length 67768 in class file WorkflowScript
I am not proud of this. I'm tying to split the workflow into smaller scripts that we load from the main workflow script, but are running into an issue with variable scoping. For example:
def a = 'foo' //some variable referenced in multiple workflow stages
node {
echo a
}
//... and then a whole bunch of other stages
might become
def a = 'foo' //some variable referenced in multiple workflow stages
node {
git: ...
load 'flowPartA.groovy'
}()
where flowPartA.groovy looks like:
{ ->
node {
echo a
}
}
Based on my understanding of the documentation, where flowPartA.groovy is interpreted as a closure, I expect the variable 'a' would remain in scope, but instead, I get an exception to the contrary.
groovy.lang.MissingPropertyException: No such property: a for class: groovy.lang.Binding
Am I missing something about the way workflow interprets the flow scripts? Is there a good way to take a huge workflow that uses many, many parameters and split it into smaller chunks?
You have to define a function in the external groovy and call it passing all required parameters:
def a = 'foo'
node('slave') {
git '…'
def flow = load 'flowPartA.groovy'
flow.echoFromA(a)
}
And flowPartA.groovy contains:
def echoFromA(String a) {
echo a
}
return this
See the documentation for more information.

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