Skip PCT by default on PRs

Jenkinsfile

@@ -41,7 +41,6 @@ def parsePlugins(plugins) {
 
 def pluginsByRepository
 def lines
-def fullTest = env.CHANGE_ID && pullRequest.labels.contains('full-test')
 
 stage('prep') {
   mavenEnv(jdk: 11) {
@@ -61,10 +60,6 @@ stage('prep') {
       pluginsByRepository = parsePlugins(plugins)
 
       lines = readFile('lines.txt').split('\n')
-      if (env.CHANGE_ID && !fullTest) {
-        // run PCT only on newest and oldest lines, to save resources (but check all lines on deliberate master builds)
-        lines = [lines[0], lines[-1]]
-      }
       launchable.install()
       withCredentials([string(credentialsId: 'launchable-jenkins-bom', variable: 'LAUNCHABLE_TOKEN')]) {
         lines.each { line ->
@@ -85,35 +80,37 @@ stage('prep') {
   }
 }
 
-branches = [failFast: !fullTest]
-lines.each {line ->
-  pluginsByRepository.each { repository, plugins ->
-    branches["pct-$repository-$line"] = {
-      def jdk = line == 'weekly' ? 17 : 11
-      mavenEnv(jdk: jdk) {
-        unstash line
-        withEnv([
-          "PLUGINS=${plugins.join(',')}",
-          "LINE=$line",
-          'EXTRA_MAVEN_PROPERTIES=maven.test.failure.ignore=true:surefire.rerunFailingTestsCount=1'
-        ]) {
-          sh '''
-          mvn -v
-          bash pct.sh
-          '''
-        }
-        launchable.install()
-        withCredentials([string(credentialsId: 'launchable-jenkins-bom', variable: 'LAUNCHABLE_TOKEN')]) {
-          launchable('verify')
-          def sessionFile = "launchable-session-${line}.txt"
-          unstash sessionFile
-          def session = readFile(sessionFile).trim()
-          launchable("record tests --session ${session} --group ${repository} maven './**/target/surefire-reports' './**/target/failsafe-reports'")
+if (BRANCH_NAME == 'master' || env.CHANGE_ID && pullRequest.labels.contains('full-test')) {
+  branches = [failFast: false]
+  lines.each {line ->
+    pluginsByRepository.each { repository, plugins ->
+      branches["pct-$repository-$line"] = {
+        def jdk = line == 'weekly' ? 17 : 11
+        mavenEnv(jdk: jdk) {
+          unstash line
+          withEnv([
+            "PLUGINS=${plugins.join(',')}",
+            "LINE=$line",
+            'EXTRA_MAVEN_PROPERTIES=maven.test.failure.ignore=true:surefire.rerunFailingTestsCount=1'
+          ]) {
+            sh '''
+            mvn -v
+            bash pct.sh
+            '''
+          }
+          launchable.install()
+          withCredentials([string(credentialsId: 'launchable-jenkins-bom', variable: 'LAUNCHABLE_TOKEN')]) {
+            launchable('verify')
+            def sessionFile = "launchable-session-${line}.txt"
+            unstash sessionFile
+            def session = readFile(sessionFile).trim()
+            launchable("record tests --session ${session} --group ${repository} maven './**/target/surefire-reports' './**/target/failsafe-reports'")
+          }
         }
       }
     }
   }
+  parallel branches
 }
-parallel branches
 
 infra.maybePublishIncrementals()

README.md

@@ -145,7 +145,7 @@ If the build fails due to an unmanaged transitive plugin dependency, add it to
 
 ## PCT
 
-The CI build tries running the [Plugin Compatibility Tester (PCT)](https://github.com/jenkinsci/plugin-compat-tester/)
+The CI build can run the [Plugin Compatibility Tester (PCT)](https://github.com/jenkinsci/plugin-compat-tester/)
 on the particular combination of plugins being managed by the BOM.
 This catches mutual incompatibilities between plugins
 (as revealed by their `JenkinsRule` tests)
@@ -168,7 +168,10 @@ DOCKERIZED=true
 
 to reproduce image-specific failures.
 
-Note that to minimize build time, tests are run only on Linux, against JDK 8, and without Docker support.
+To minimize cloud resources, PCT is not run at all by default on pull requests, only some basic sanity checks.
+Add the label `full-test` to run PCT in a PR.
+
+To further minimize build time, tests are run only on Linux, against Java 11, and without Docker support.
 It is unusual but possible for cross-component incompatibilities to only be visible in more specialized environments (such as Windows).
 
 ## LTS lines
@@ -187,10 +190,6 @@ The UC currently maintains releases for the [past 400 days](https://groups.googl
 so it is reasonable to retire BOMs for lines older than that,
 or otherwise when the number of accumulated version overrides becomes large.
 
-Add the label `full-test` in dangerous-looking PRs to make sure you are running tests in all LTS lines;
-by default tests are only run in the oldest line and weeklies.
-This flag also allows all tests to be run even after some failures are recorded.
-
 ## Releasing
 
 You can cut a release using [JEP-229](https://jenkins.io/jep/229).

updatecli/updatecli.d/plugin-compat-tester.yml

@@ -43,3 +43,4 @@ actions:
     spec:
       labels:
         - dependencies
+        - full-test