Use IDE to generate pipline script for jenkins - jenkins

I need to overload jenkins functions to debug pipeline script in IDE.
I'm new to java/groovy etc. I'm going to write a several hundred lines scripted pipeline. Groovy is based on java. As I'm new I prefer the function name completion/suggestion and a debugging feature would be awesome where I can walk through the lines step by step and see what is in the vars.
I set up a eclipse Luna with the groovy-plugin. Which is actually working =)! (for newest eclipse the plugin is not yet ready). Also debugging is quiet cool!
But special jenkins expressions will still throw errors.
node(MasterName){ ... }
sh
...
Is there a chance to overload those functions?
Just killing the error, not performing any actions. Maybe converting it to a print like "I'm executing script XYZ" or "Switching to node BLUBB"?
The outcome should be a copy paste script, for checking in and running with jenkins without major changes.
Is there any better way?

In the end it turned out, that even if you omit the pipeline specific expressions, you will still have trouble. In some more complex situations e.g. calling a constructor with super in a extended class and executing a function afterwards, it does not behave the same then in my local python interpreter.
So what I did was an error to assume, my Ubuntu system default groovy interpreter would work the same like the jenkins interpreter. It would be nice to run a debugger inside the jenkins environment, or going step by step through the pipeline script and see how it is actually working without a print in every second line.

Related

Jenkins execute command only if previous one failed

I have the following problem. I have a command that unfortunately only works from time to time in powershell. Sometimes an error comes sometimes it runs through.
Now I am looking for an option in the declarative Jenkins pipeline to execute a step, if this step fails it should execute another command.
However, if the first command runs through, skip the second command, because it is then no longer necessary.
Unfortunately I don't know at all how to implement this.
I have thought about catch error.
I have thought about if else .
Maybe what you need it's already resolved here. I've been working with try/catch because I had same issues of unstable executions and works like a charm.
Try-catch block in Jenkins pipeline script

Is a Jenkinsfile valid standalone groovy?

I'm trying to wrap my head around how this declarative Jenkinsfile is Groovy. I want to write supporting code to execute this outside the Jenkins environment, in pure Groovy, if that's possible. I've been writing example groovy code but still am unsure what "pipeline", "agent", and "stages" are.
Any tips to understand this structure is appreciated
EDIT: I edited this question with simplified code below. I'm just wondering if there is a way that this can be turned into valid groovy code without the preprocessor/groovyshell environment that is utilized by Jenkins
pipeline {
stages {
// extra code here
}
}
No, you can't run Jenkinsfile as a standalone Groovy script. In short, Jenkins executes the pipeline code inside a pre-configured GroovyShell that knows how to evaluate things like pipeline, agent, stages, and so forth. However, there is a way to execute Jenkinsfie without the Jenkins server - you can use JenkinsPipelineUnit test library to write JUnit/Spock unit tests that will evaluate your Jenkinsfile and display the call stack tree. It uses mocks, so you can treat it as interaction-based testing, to see if a specific part of your pipeline gets executed. Plus, you can catch some code errors prior to running the pipeline on the server.
A simple unit test for the declarative pipeline can look like this:
import com.lesfurets.jenkins.unit.declarative.*
class TestExampleDeclarativeJob extends DeclarativePipelineTest {
#Test
void should_execute_without_errors() throws Exception {
def script = runScript("Jenkinsfile")
assertJobStatusSuccess()
printCallStack()
}
}
You can find more examples in the official README.md - https://github.com/jenkinsci/JenkinsPipelineUnit
Alternatively, you can try Jenkinsfile Runner command-line tool that can execute your Jenkinsfile outside of the Jenkins server - https://github.com/jenkinsci/jenkinsfile-runner
UPDATE
I edited this question with simplified code below. I'm just wondering if there is a way that this can be turned into valid groovy code without the preprocessor/groovyshell environment that is utilized by Jenkins.
Your pipeline code example looks like a valid Jenkinsfile, but you can't turned it into a Groovy code that can be run e.g. from the command-line as a regular Groovy script:
$ groovy Jenkinsfile
This won't work, because Groovy is not aware of the Jenkins Pipeline syntax. The syntax is added as a DSL via the Jenkins plugin, and it uses a dedicated GroovyShell that is pre-configured to interpret the pipeline syntax correctly.
If you are interested in checking if the syntax of the Jenkins Pipeline is correct, there are a few different options:
npm-groovy-lint (https://github.com/nvuillam/npm-groovy-lint) can validate (and even auto-fix) the syntax of your Jenkinsfile without connecting to the Jenkins server,
Command-Line Pipeline Linter (https://www.jenkins.io/doc/book/pipeline/development/#linter) can send your pipeline code to the Jenkins server and validate its syntax.
These are a few tools that can help you with catching up the syntax errors before you run the pipeline. But that's just a nice addon to your toolbox. The first step, as always, is to understand what the syntax means, and the official documentation (https://www.jenkins.io/doc/book/pipeline/syntax) is the best place to start.

Can Jenkins run some code or it is only scheduling external programs?

I'm new to Jenkins and I heard it is really good for continues integration.
My flow is not complicated: I need to get a list from SQL by some query, parse it line by line, send each line to some virtual machines (which will run this line and create some file as result), and then analyze the results.
Where in Jenkins can I program my code?
Is Jenkins' purpose is only to schedule external programs one by one and not to run the code in Jenkins itself?
Is there a way to write code in jenkins that is not a bunch of CMD commands?
you can do the following ( syntaxic pipline ) :
- stage 1 : execute command over ssh (jenkins plugin) to execute sql query
- stage 2 : send each line to dedicated VM with Ansible playbook
- stage 3 : analyze depend on the tech you are using there are plenty of jenkins plugin to connect to monitoring and analyzing tools like grafana or zabbix .. that can ease the process
I think what you are asking for is scripted pipeline: https://jenkins.io/doc/book/pipeline/
This allows you to write Groovy code to execute on the Jenkins master. You can do almost anything you want from there, just like any programming language.

Jenkins plugin cannot see variables set using the withEnv workflow step

I want the gradle plugin to pick up environment variables that are set in a withEnv step (or other wrapper-types). When I invoke gradle using a sh step the variable is found, but when I use the gradle plugin it is not.
The gradle plugin performs the equivalent of this:
EnvVars env = run.getEnvironment(taskListener);
launcher.launch().cmds(args).envs(env).stdout(gca)
.pwd(rootLauncher).join();
The javadoc for run.getEnvironment() states:
Returns the map that contains environmental variables to be used for
launching processes for this build. BuildSteps that invoke external
processes should use this. This allows BuildWrappers and other project
configurations (such as JDK selection) to take effect.
Unlike earlier getEnvVars(), this map contains the whole environment,
not just the overrides, so one can introspect values to change its
behavior.
If I debug the plugin I see that there are less than a dozen variables in the environment passed to the gradle invocation, none of which are the variables withEnv should be providing. To the best I could tell, the sh step uses a completely different extension point, and is straight up given an instance of EnvVars that appears to be much more complete. I'm fairly certain the problem isn't in withEnv, but I don't see how to fix the gradle plugin.
Am I using the wrong call? Or perhaps the wrong extension point?
Do not call Run.getEnvironment. Rather use the EnvVars passed to SimpleBuildStep.perform.

Jenkins - Make pass/fail dependent on results from script command

I'm admittedly very new to using Jenkins, so I apologize if this is something simple I'm overlooking. In my Jenkins job, I have a bash command to run a Python script. Everything runs correctly at the moment, and the Python script works. However, the script can give a pass or fail result after running (to clarify, a fail doesn't mean the script crashed, just that it ran through and, with the variables given, gave the result that with those variables it is wrong). I need to make it so the job fails when the "fail" result is given, but I can't figure out a way to make the Jenkins pass/fail dependent on anything other than whether everything runs properly. How can I set it in such a way that whether the job passes or fails depends on the python script output? Thanks in advance for your help!
So from what I could figure out, the easiest way to do this is to modify the Python script so that it exits with a non-zero value when it returns the undesirable value, and with zero otherwise, so the success of the job will mimic the success of the script.

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