Ability to set P2 mirror for Maven plugin

[jglick]

I have been getting sporadic errors like

[ERROR] Failed to execute goal com.diffplug.spotless:spotless-maven-plugin:2.36.0:check (default) on project …: Execution default of goal com.diffplug.spotless:spotless-maven-plugin:2.36.0:check failed: 502 at https://groovy.jfrog.io/artifactory/plugins-release/org/codehaus/groovy/groovy-eclipse-integration/4.8.0/e4.26/plugins/org.codehaus.groovy_4.0.7.v202212311456-e2212-RELEASE.jar -> [Help 1]
org.apache.maven.lifecycle.LifecycleExecutionException: Failed to execute goal com.diffplug.spotless:spotless-maven-plugin:2.36.0:check (default) on project …: Execution default of goal com.diffplug.spotless:spotless-maven-plugin:2.36.0:check failed: 502 at https://groovy.jfrog.io/artifactory/plugins-release/org/codehaus/groovy/groovy-eclipse-integration/4.8.0/e4.26/plugins/org.codehaus.groovy_4.0.7.v202212311456-e2212-RELEASE.jar
    at org.apache.maven.lifecycle.internal.MojoExecutor.doExecute2 (MojoExecutor.java:347)
    at …
Caused by: org.apache.maven.plugin.PluginExecutionException: Execution default of goal com.diffplug.spotless:spotless-maven-plugin:2.36.0:check failed: 502 at https://groovy.jfrog.io/artifactory/plugins-release/org/codehaus/groovy/groovy-eclipse-integration/4.8.0/e4.26/plugins/org.codehaus.groovy_4.0.7.v202212311456-e2212-RELEASE.jar
    at org.apache.maven.plugin.DefaultBuildPluginManager.executeMojo (DefaultBuildPluginManager.java:133)
    at …
Caused by: java.lang.IllegalArgumentException: 502 at https://groovy.jfrog.io/artifactory/plugins-release/org/codehaus/groovy/groovy-eclipse-integration/4.8.0/e4.26/plugins/org.codehaus.groovy_4.0.7.v202212311456-e2212-RELEASE.jar
    at dev.equo.solstice.p2.JarCache.download (JarCache.java:52)
    at dev.equo.solstice.p2.P2Client.download (P2Client.java:69)
    at dev.equo.solstice.p2.P2QueryResult.<init> (P2QueryResult.java:35)
    at dev.equo.solstice.p2.P2Model.query (P2Model.java:126)
    at com.diffplug.spotless.extra.EquoBasedStepBuilder.get (EquoBasedStepBuilder.java:103)
    at com.diffplug.spotless.FormatterStepImpl.calculateState (FormatterStepImpl.java:58)
    at com.diffplug.spotless.LazyForwardingEquality.state (LazyForwardingEquality.java:56)
    at com.diffplug.spotless.LazyForwardingEquality.toBytes (LazyForwardingEquality.java:85)
    at com.diffplug.spotless.LazyForwardingEquality.hashCode (LazyForwardingEquality.java:102)
    at java.util.ArrayList.hashCodeRange (ArrayList.java:627)
    at java.util.ArrayList.hashCode (ArrayList.java:614)
    at com.diffplug.spotless.Formatter.hashCode (Formatter.java:276)
    at java.util.HashMap.hash (HashMap.java:340)
    at java.util.HashMap.put (HashMap.java:608)
    at com.diffplug.spotless.maven.FormattersHolder.create (FormattersHolder.java:43)
    at com.diffplug.spotless.maven.AbstractSpotlessMojo.execute (AbstractSpotlessMojo.java:224)
    at …

This despite my ~/.m2/settings.xml defining a mirrorOf pointing to a Nexus pull-through proxy of Maven Central, violating the general expectation of Maven plugins.

If this artifact, whatever it is, cannot be hosted on Central, then is there at least some way to define a separate mirror for it so CI builds are not at the mercy of an external server?

#1635 seems to only support Gradle. #1669 sounds related but then discusses Gradle as well. #1658 sounds related but distinct—about a generic HTTP proxy, rather than a mirror.

[jtnord]

it should be noted that the configuration of spotless here is only using

      <plugin>
        <groupId>com.diffplug.spotless</groupId>
        <artifactId>spotless-maven-plugin</artifactId>
        <configuration>
          <java>
            <endWithNewline />
            <importOrder />
            <indent>
              <spaces>true</spaces>
            </indent>
            <palantirJavaFormat />
            <removeUnusedImports />
            <trimTrailingWhitespace />
          </java>
          <pom>
            <sortPom>
              <expandEmptyElements>false</expandEmptyElements>
              <sortDependencies>scope,groupId,artifactId</sortDependencies>
              <sortDependencyExclusions>groupId,artifactId</sortDependencyExclusions>
              <spaceBeforeCloseEmptyElement>true</spaceBeforeCloseEmptyElement>
            </sortPom>
          </pom>
        </configuration>

so it is not even clear why non configured formatters are even configured/run.

[jglick]

Well, the case I encountered in https://github.com/jenkinsci/jenkins was actually using

<groovy>
  <includes>
    <include>…</include>
  </includes>
  <greclipse>
    <file>config/greclipse.properties</file>
  </greclipse>
</groovy>

By adding to my /etc/hosts

240.0.0.0 groovy.jfrog.io
240.0.0.0 download.eclipse.org

I was able to reproduce in a tight loop:

./gradlew publishToMavenLocal && \
  mv ~/.equo ~/.equo.bak && \
  (trap 'rm -rf ~/.equo && mv ~/.equo.bak ~/.equo' EXIT; \
    mvn -f …/jenkins -pl websocket/jetty10 spotless:check -Dspotless-maven-plugin.version=2.36.1-SNAPSHOT -e)

It passes with

diff --git plugin-maven/src/main/java/com/diffplug/spotless/maven/AbstractSpotlessMojo.java plugin-maven/src/main/java/com/diffplug/spotless/maven/AbstractSpotlessMojo.java
index 0b019ea8..a817dfef 100644
--- plugin-maven/src/main/java/com/diffplug/spotless/maven/AbstractSpotlessMojo.java
+++ plugin-maven/src/main/java/com/diffplug/spotless/maven/AbstractSpotlessMojo.java
@@ -358,7 +358,7 @@ public abstract class AbstractSpotlessMojo extends AbstractMojo {
 	}
 
 	private List<FormatterFactory> getFormatterFactories() {
-		return Stream.concat(formats.stream(), Stream.of(groovy, java, scala, kotlin, cpp, typescript, javascript, antlr4, pom, sql, python, markdown, json, yaml, gherkin))
+		return Stream.concat(formats.stream(), Stream.of(java, scala, kotlin, cpp, typescript, javascript, antlr4, pom, sql, python, markdown, json, yaml, gherkin))
 				.filter(Objects::nonNull)
 				.collect(toList());
 	}

(I guess silently declining to format Groovy files?)

[nedtwigg]

Yeah, eclipse.org was down with 502 errors ~two weeks ago, so that's what was happening.

• Support configuration of P2 mirrors #1635 makes p2 mirroring work, and then adds it to the Gradle DSL.
• You are correct that it has not been exposed in the Maven DSL, a PR for that is welcome.