I have developed a custom Maven plugin and deployed it (mvn deploy) on a remote Nexus repository. The jar is correctly uploaded with a pom like this:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion>
<groupId>something</groupId>
<artifactId>xxx-maven-plugin</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>maven-plugin</packaging>
The jar contains the necessary plugin.xml file so it looks good.
I have configured a project to use the plugin:
<plugins>
<plugin>
<groupId>something</groupId>
<artifactId>xxx-maven-plugin</artifactId>
<version>1.0.0-SNAPSHOT</version>
</plugin>
...
But when I run mvn xxx:mygoal it shows this error:
[ERROR] No plugin found for prefix 'xxx' in the current project and in the plugin groups [org.apache.maven.plugins, org.codehaus.mojo] available from the repositories [local (/Users/myuser/.m2/repository), remote-repo (http://someremoterepo/nexus/content/groups/central/)] -> [Help 1]
The only thing to make it work is adding the plugin both as a plugin and as a dependency in the project:
...
<dependency>
<groupId>something</groupId>
<artifactId>xxx-maven-plugin</artifactId>
<version>1.0.0-SNAPSHOT</version>
</dependency>
</dependencies>
<plugins>
<plugin>
<groupId>something</groupId>
<artifactId>xxx-maven-plugin</artifactId>
<version>1.0.0-SNAPSHOT</version>
</plugin>
...
Now it does find the plugin and executes it correctly. What am I doing wrong? I guess it shouldn't be necessary to have it defined both as a plugin and a dependency, the other third party plugins don't have that requirement.
UPDATE:
I have added this to my settings.xml file:
<pluginGroup>something</pluginGroup>
</pluginGroups>
Now the error is different:
[WARNING] The POM for something:xxx-maven-plugin:jar:1.0.0-SNAPSHOT is missing, no dependency information available
[WARNING] Failed to retrieve plugin descriptor for something:xxx-maven-plugin:1.0.0-SNAPSHOT: Plugin something:xxx-maven-plugin:1.0.0-SNAPSHOT or one of its dependencies could not be resolved: Could not find artifact something:xxx-maven-plugin:jar:1.0.0-SNAPSHOT
[WARNING] The POM for something:xxx-maven-plugin:jar:1.0.0-SNAPSHOT is missing, no dependency information available
...
[ERROR] Plugin something:xxx-maven-plugin:1.0.0-SNAPSHOT or one of its dependencies could not be resolved: Could not find artifact something:xxx-maven-plugin:jar:1.0.0-SNAPSHOT -> [Help 1]
It IS actually in the repo. Again if I explicitly add it as a dependency it does work. ???
UPDATE 2:
Using the Nexus GAV search interface I look for a plugin with artifactId spring-boot-maven-plugin and packaging maven-plugin and it finds it. Using packaging jar it also finds it.
Then I do the same with my plugin, when looking for packaging maven-plugin it finds it but it doesn't when using packaging jar.
UPDATE 3:
In my local repo there is a maven-metadata-central-mirror.xml file with this content:
<?xml version="1.0" encoding="UTF-8"?>
<metadata>
<plugins>
<plugin>
<name>something</name>
<prefix>xxx</prefix>
<artifactId>xxx-maven-plugin</artifactId>
</plugin>
</plugins>
</metadata>
FULL CONFIGURATION
Local settings.xml:
<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
<localRepository>/Users/myuser/.m2/repository</localRepository>
<pluginGroups>
<pluginGroup>something</pluginGroup>
</pluginGroups>
<proxies>
</proxies>
<servers>
<server>
<id>someremoterepo</id>
<username>xxxx</username>
<password>yyyy</password>
</server>
</servers>
<mirrors>
<mirror>
<id>someremoterepo</id>
<name>Nexus Repo</name>
<url>http://someremoterepo/nexus/content/groups/central/</url>
<mirrorOf>*</mirrorOf>
</mirror>
</mirrors>
<profiles>
<profile>
<id>myprofile</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<repositories>
<repository>
<id>central</id>
<name>Central</name>
<releases>
<enabled>true</enabled>
<checksumPolicy>warn</checksumPolicy>
</releases>
<snapshots>
<enabled>true</enabled>
<updatePolicy>never</updatePolicy>
<checksumPolicy>fail</checksumPolicy>
</snapshots>
<url>http://someremoterepo/nexus/content/groups/central</url>
</repository>
</repositories>
</profile>
</profiles>
</settings>
Custom plugin pom.xml:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>something</groupId>
<artifactId>xxx-maven-plugin</artifactId>
<version>1.0.0-SNAPSHOT</version>
<packaging>maven-plugin</packaging>
<name>xxx-maven-plugin</name>
<description>xxx</description>
<properties>
<project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
<project.reporting.outputEncoding>UTF-8</project.reporting.outputEncoding>
<java.version>1.8</java.version>
<kotlin.version>1.2.21</kotlin.version>
<junit5.version>5.0.3</junit5.version>
</properties>
<dependencies>
<dependency>
<groupId>org.apache.maven</groupId>
<artifactId>maven-project</artifactId>
<version>2.2.1</version>
</dependency>
<dependency>
<groupId>org.apache.maven</groupId>
<artifactId>maven-plugin-api</artifactId>
<version>3.3.9</version>
</dependency>
<dependency>
<groupId>org.apache.maven.plugin-tools</groupId>
<artifactId>maven-plugin-annotations</artifactId>
<version>3.5.1</version>
<scope>provided</scope>
</dependency>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-stdlib-jdk8</artifactId>
<version>${kotlin.version}</version>
</dependency>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-reflect</artifactId>
<version>${kotlin.version}</version>
</dependency>
<dependency>
<groupId>commons-logging</groupId>
<artifactId>commons-logging</artifactId>
<version>1.2</version>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-api</artifactId>
<version>${junit5.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.junit.jupiter</groupId>
<artifactId>junit-jupiter-engine</artifactId>
<version>${junit5.version}</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-test</artifactId>
<version>1.5.10.RELEASE</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>com.github.sbrannen</groupId>
<artifactId>spring-test-junit5</artifactId>
<version>1.0.2</version>
<scope>test</scope>
</dependency>
</dependencies>
<build>
<sourceDirectory>${project.basedir}/src/main/kotlin</sourceDirectory>
<testSourceDirectory>${project.basedir}/src/test/kotlin</testSourceDirectory>
<plugins>
<plugin>
<groupId>org.jacoco</groupId>
<artifactId>jacoco-maven-plugin</artifactId>
<version>0.8.0</version>
<executions>
<execution>
<id>jacoco-initialize</id>
<phase>initialize</phase>
<goals>
<goal>prepare-agent</goal>
</goals>
</execution>
</executions>
</plugin>
<plugin>
<artifactId>kotlin-maven-plugin</artifactId>
<groupId>org.jetbrains.kotlin</groupId>
<version>${kotlin.version}</version>
<configuration>
<args>
<arg>-Xjsr305=strict</arg>
</args>
<compilerPlugins>
<plugin>spring</plugin>
</compilerPlugins>
<jvmTarget>1.8</jvmTarget>
</configuration>
<executions>
<execution>
<id>compile</id>
<phase>compile</phase>
<goals>
<goal>compile</goal>
</goals>
</execution>
<execution>
<id>test-compile</id>
<phase>test-compile</phase>
<goals>
<goal>test-compile</goal>
</goals>
</execution>
</executions>
<dependencies>
<dependency>
<groupId>org.jetbrains.kotlin</groupId>
<artifactId>kotlin-maven-allopen</artifactId>
<version>${kotlin.version}</version>
</dependency>
</dependencies>
</plugin>
</plugins>
</build>
<distributionManagement>
<repository>
<id>someremoterepo-releases</id>
<name>releases</name>
<url>http://someremoterepo/nexus/content/repositories/releases/</url>
</repository>
<snapshotRepository>
<id>someremoterepo-snapshots</id>
<name>snapshots</name>
<url>http://someremoterepo/nexus/content/repositories/snapshots/</url>
</snapshotRepository>
</distributionManagement>
</project>
Project that includes the plugin:
The only relevant bit is:
<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
<modelVersion>4.0.0</modelVersion>
<groupId>agroup</groupId>
<artifactId>some-project</artifactId>
<version>0.0.1-SNAPSHOT</version>
<packaging>jar</packaging>
...
<parent>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-parent</artifactId>
<version>1.5.10.RELEASE</version>
<relativePath/> <!-- lookup parent from repository -->
</parent>
...
<plugins>
<plugin>
<groupId>something</groupId>
<artifactId>xxx-maven-plugin</artifactId>
<version>1.0.0-SNAPSHOT</version>
</plugin>
<plugin>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-maven-plugin</artifactId>
</plugin>
...
After a lot of struggling I finally fixed this, the solution was defining pluginRepositories in the settings.xml file. Now it resolves the plugin correctly without the need to add it as a dependency in the project pom:
<?xml version="1.0" encoding="UTF-8"?>
<settings xmlns="http://maven.apache.org/SETTINGS/1.0.0"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.0.0 http://maven.apache.org/xsd/settings-1.0.0.xsd">
<localRepository>/Users/myuser/.m2/repository</localRepository>
<pluginGroups>
<pluginGroup>something</pluginGroup>
</pluginGroups>
<proxies>
</proxies>
<servers>
<server>
<id>someremoterepo</id>
<username>xxxx</username>
<password>yyyy</password>
</server>
</servers>
<mirrors>
<mirror>
<id>someremoterepo</id>
<name>Nexus Repo</name>
<url>http://someremoterepo/nexus/content/groups/central/</url>
<mirrorOf>*</mirrorOf>
</mirror>
</mirrors>
<profiles>
<profile>
<id>myprofile</id>
<activation>
<activeByDefault>true</activeByDefault>
</activation>
<repositories>
<repository>
<id>central</id>
<name>Central</name>
<releases>
<enabled>true</enabled>
<checksumPolicy>warn</checksumPolicy>
</releases>
<snapshots>
<enabled>true</enabled>
<updatePolicy>never</updatePolicy>
<checksumPolicy>fail</checksumPolicy>
</snapshots>
<url>http://someremoterepo/nexus/content/groups/central</url>
</repository>
</repositories>
<pluginRepositories>
<pluginRepository>
<id>central</id>
<name>Central</name>
<releases>
<enabled>true</enabled>
<checksumPolicy>warn</checksumPolicy>
</releases>
<snapshots>
<enabled>true</enabled>
<updatePolicy>never</updatePolicy>
<checksumPolicy>fail</checksumPolicy>
</snapshots>
<url>http://someremoterepo/nexus/content/groups/central</url>
</pluginRepository>
</pluginRepositories>
</profile>
</profiles>
</settings>