Jenkinsfile参数默认值无法获取env.BUILD_NUMBER实际值问题

Got it, let's break down what's happening here and how to fix it quickly.

The Root Cause #

Your issue is that in the parameters block of your declarative pipeline, wrapping ${env.BUILD_NUMBER} in double quotes tells Jenkins to treat it as a literal string rather than evaluating the variable. Declarative DSL doesn't automatically interpolate variables inside double quotes in the parameters section the way you'd expect in regular Groovy code.

The Fix #

All you need to do is remove the double quotes around the default value and directly reference the env.BUILD_NUMBER variable. Since env.BUILD_NUMBER is already a string, no extra conversion is needed:

string(
    name: 'DEPLOY_BUILD_NUMBER',
    defaultValue: env.BUILD_NUMBER,
    description: 'Fresh Build and Deploy OR Deploy Previous Build Number'
)

While you're at it, there's another small issue in your CopyArtifact step: you're using single quotes for '${JOB_NAME}', which also won't interpolate. Switch to using the env.JOB_NAME variable directly (or double quotes if you prefer):

projectName: env.JOB_NAME,

Full Modified Jenkinsfile #

Here's the complete pipeline with both fixes applied:

pipeline { 
    agent { label 'windows' } 
    options { copyArtifactPermission("${JOB_NAME}"); } 
    parameters { 
        string( 
            name: 'DEPLOY_BUILD_NUMBER', 
            defaultValue: env.BUILD_NUMBER, 
            description: 'Fresh Build and Deploy OR Deploy Previous Build Number' 
        ) 
    } 
    stages { 
        stage ('Build') { 
            steps { 
                sh ''' 
                    echo "Building Project" 
                    echo "Packaging into tar.gz" 
                ''' 
            } 
            post { 
                success { archiveArtifacts artifacts: '*.tar.gz' } 
            } 
        } 
        stage ('Deploy') { 
            steps { 
                echo "Deploying...." 
                echo "${params.DEPLOY_BUILD_NUMBER}" 
                echo "${env.BUILD_NUMBER}" 
                script { 
                    step ([$class: 'CopyArtifact', 
                        projectName: env.JOB_NAME, 
                        filter: "*.tar.gz", 
                        fingerprintArtifacts: true, 
                        selector: [$class: 'SpecificBuildSelector', buildNumber: "${params.DEPLOY_BUILD_NUMBER}"] 
                    ]); 
                } 
            } 
        } 
    } 
    post { 
        success { 
            script { currentBuild.displayName = "#${BUILD_NUMBER}" } 
        } 
    } 
}

Why This Works #

• By removing the double quotes from defaultValue, Jenkins now references the actual env.BUILD_NUMBER variable value that's assigned when the pipeline initializes, instead of treating it as a static string.
• Using env.JOB_NAME in the CopyArtifact step ensures Jenkins uses the current job's name correctly, avoiding any interpolation failures from single-quoted strings.

内容的提问来源于stack exchange，提问作者rp346