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Bug
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Resolution: Unresolved
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Minor
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None
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ubuntu
jenkins 2.249.3
jdk8
There are 2 questions ：
1。 pipeline/freestylejob cannot get empty param value。 2。 pipeline under docker agent can get empty param value。
I define the pipelie with parameter like below
parameters {
string(name: 'ANDROID_PLATFORM', defaultValue: '')
}
in stage i try to print this parameter 'ANDROID_PLATFORM', like below
stage("0.clean ws") {
steps {
sh '''#!/bin/bash
env
'''
}
}
start this pipeline with empty string ANDROID_PLATFORM, the env command not print this value.
in python code i try to get ANDROID_PLATFORM like this
os.environ.get("ANDROID_PLATFORM")
but this return None.I want this return "", an empty string value。
workaround in python maybe work well like this：
os.environ.get("ANDROID_PLATFORM", "")
- relates to
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- Resolved
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[JENKINS-65066] pipeline/freestylejob cannot get empty param value
I define a free style job with parameters looks like this:
I try to debug the code, and tracking the jenkin code execution flow:
the envVars contains the empty parameters
Maybe these empty envVars were deleted somewhere in the code .
in public static class LocalLauncher extends Launcher class I found they were deleted by "EnvVars jobEnv = inherit(ps.envs);" at https://github.com/jenkinsci/jenkins/blob/b25281994720ee4adce0ff16bae4333d27593f58/core/src/main/java/hudson/Launcher.java#L979
maybe this use-case was not supported in Jenkins at beginning。
but if run under pipeline with docker agent like below:
pipeline {
agent {
docker {
image 'maven:3-alpine'
args '-v $HOME/.m2:/root/.m2'
label 'docker-01'
}
}
parameters {
string(name: 'ANDROID_PLATFORM')
}
stages {
stage('Build') {
steps {
sh 'env'
}
}
}
}
Started by user unknown or anonymous
Replayed #42
Running in Durability level: MAX_SURVIVABILITY
[Pipeline] Start of Pipeline
[Pipeline] node
Running on docker-01 in /tmp/docker-01/workspace/test_pipeline
[Pipeline] {
[Pipeline] isUnix
[Pipeline] sh
+ docker inspect -f . maven:3-alpine
.
[Pipeline] withDockerContainer
docker-01 does not seem to be running inside a container
$ docker run -t -d -u 1000:1000 -v $HOME/.m2:/root/.m2 -w /tmp/docker-01/workspace/test_pipeline -v /tmp/docker-01/workspace/test_pipeline:/tmp/docker-01/workspace/test_pipeline:rw,z -v /tmp/docker-01/workspace/test_pipeline@tmp:/tmp/docker-01/workspace/test_pipeline@tmp:rw,z -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** -e ******** maven:3-alpine cat
$ docker top 77f3858dd91a10ee59db7ca27678001783012cd5b46801e779da9a5b5f63d3c4 -eo pid,comm
[Pipeline] {
[Pipeline] stage
[Pipeline] { (Build)
[Pipeline] sh
+ env
JENKINS_HOME=/work/brightma/github/jenkins/war/work
JAVA_ALPINE_VERSION=8.131.11-r2
HOSTNAME=77f3858dd91a
RUN_CHANGES_DISPLAY_URL=http://10.0.12.116:8080/jenkins/job/test_pipeline/85/display/redirect?page=changes
BRANCH=
NODE_LABELS=docker-01
HUDSON_URL=http://10.0.12.116:8080/jenkins/
SHLVL=2
ASSIGNER=
HOME=/
BUILD_URL=http://10.0.12.116:8080/jenkins/job/test_pipeline/85/
CONFIG_BRANCH=
BUILD_TYPE=
JENKINS_SERVER_COOKIE=durable-9c5625ac73e1e26a7682d97c02c19744
MAVEN_HOME=/usr/share/maven
WORKSPACE=/tmp/docker-01/workspace/test_pipeline
AAIS_CLEAN_OUT=false
JAVA_VERSION=8u131
GROUP_ID=
NODE_NAME=docker-01
RUN_ARTIFACTS_DISPLAY_URL=http://10.0.12.116:8080/jenkins/job/test_pipeline/85/display/redirect?page=artifacts
EXECUTOR_NUMBER=0
STAGE_NAME=Build
BUILD_DISPLAY_NAME=#85
RUN_TESTS_DISPLAY_URL=http://10.0.12.116:8080/jenkins/job/test_pipeline/85/display/redirect?page=tests
JOB_BASE_NAME=test_pipeline
HUDSON_HOME=/work/brightma/github/jenkins/war/work
AAIS_CLEAN_ALL=false
PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/lib/jvm/java-1.8-openjdk/jre/bin:/usr/lib/jvm/java-1.8-openjdk/bin
BUILD_ID=85
IMAGEMODE=
BUILD_TAG=jenkins-test_pipeline-85
JENKINS_URL=http://10.0.12.116:8080/jenkins/
LANG=C.UTF-8
JOB_URL=http://10.0.12.116:8080/jenkins/job/test_pipeline/
BUILD_NUMBER=85
JENKINS_NODE_COOKIE=9ea59d35-1e8c-418e-998b-910f8cedadd4
RUN_DISPLAY_URL=http://10.0.12.116:8080/jenkins/job/test_pipeline/85/display/redirect
HUDSON_SERVER_COOKIE=925e1992be03d5fd
JOB_DISPLAY_URL=http://10.0.12.116:8080/jenkins/job/test_pipeline/display/redirect
MANIFEST_FILE=
CLASSPATH=
PRODUCT=
CARRIER=
JOB_NAME=test_pipeline
JAVA_HOME=/usr/lib/jvm/java-1.8-openjdk
PWD=/tmp/docker-01/workspace/test_pipeline
MAVEN_CONFIG=/root/.m2
WORKSPACE_TMP=/tmp/docker-01/workspace/test_pipeline@tmp
VARIANT=
ANDROID_PLATFORM=
[Pipeline] }
[Pipeline] // stage
[Pipeline] }
$ docker stop --time=1 77f3858dd91a10ee59db7ca27678001783012cd5b46801e779da9a5b5f63d3c4
$ docker rm -f 77f3858dd91a10ee59db7ca27678001783012cd5b46801e779da9a5b5f63d3c4
[Pipeline] // withDockerContainer
[Pipeline] }
[Pipeline] // node
[Pipeline] End of Pipeline
Finished: SUCCESS
the linux env command show the parameter ANDROID_PLATFORM as empty string value.
Maybe these empty envVars pass to docker with -e options. see https://github.com/jenkinsci/docker-workflow-plugin/blob/eb0b0db4791ca8b40fe38f53ec7668118a82b7b4/src/main/java/org/jenkinsci/plugins/docker/workflow/client/DockerClient.java#L135
I'm not sure if I am correct
By default the Bourne shell will not distinguish an empty string from an undefined parameter; other tools like Python of course may be more precise. The trouble is that parameters are traditionally defined via the GUI config form which cannot differentiate between null and "", so in PR-5275 I normalized the value so that it will not change during round-tripping and will not result in a spurious <defaultValue></defaultValue> in persisted form. OTOH https://github.com/jglick/jenkins/blob/58174df061274fd2c3623bb3fc82a284b9e5da0c/core/src/main/java/hudson/model/StringParameterValue.java#L52 is supposed to convert null to "" so I wonder what is happening. Probably depends on the precise mechanism used to both define the parameter and trigger the build.
mmh19891113 you are really using 2.249.3 as the issue claims? In which case you were not using PR-5275, which was just merged?
Hmm, seems Declarative Pipeline behaves differently than Scripted Pipeline: an empty parameter value is not bound to an environment variable. There is also different behavior between the first build (triggered before the project is parameterized) and subsequent builds (when it has been). But both of these issues seem to be true also in 2.277.1, before PR-5275. My tentative conclusion is that defaultValue: '' is pointless and your jobs should just be prepared to handle a missing environment variable, either by being more defensive in a program run by sh/bat (like your Python workaround), or by using withEnv.
like you said an empty parameter value is not bound to an environment variable.
aggree with you we should handle the defaultValue empty value in sh or python.
what do you think "pipeline with docker agent " the defaultValue empty value was passed to docker with -e options.
see https://github.com/jenkinsci/docker-workflow-plugin/blob/eb0b0db4791ca8b40fe38f53ec7668118a82b7b4/src/main/java/org/jenkinsci/plugins/docker/workflow/client/DockerClient.java#L135
The results of these two are not the same ，1： pipeline/freestylejob cannot get empty defaultValue value。
2： pipeline under docker agent can get empty defaultValue value。
Not sure offhand why the behavior would differ in the docker-workflow plugin.
After https://github.com/jenkinsci/jenkins/pull/5275 I suspect this use-case should be considered unsupported in Jenkins. CC jglick timja for an opinion