In this article, I want to take a closer look at the process of publishing a Java artifact from scratch through Github Actions in the Sonatype Maven Central Repository using the Gradle collector.

I decided to write this article due to the lack of a normal tutorial in one place. All the information had to be collected in pieces from various sources, while not entirely fresh. Who cares, welcome to cat.

Creating a repository in Sonatype

The first step is to create a repository in Sonatype Maven Central. To do this, go here , register and create a new task, asking us to create a repository for us. We drive in our GroupId of the project, Project URL link to the project and SCM url link to the version control system in which the project lies. The GroupId here should be of the form com.example, com.example.domain, com.example.testsupport, and it can also be a link to your github: github.com/yourusername -> io.github.yourusername. In any case, you will need to confirm ownership of this domain or profile. If you specified a github profile, they will ask you to create a public repository with the desired name.

Some time after confirmation, your GroupId will be created and we can proceed to the next step, Gradle configuration.

Configuring Gradle

At the time of this writing, I did not find any plugins for Gradle that could help with the publication of the artifact. This is the only plugin I have found, however the author has refused his further support. Therefore, I decided to do everything myself, since it’s not too difficult to do it.

The first thing to find out is Sonatype's publishing requirements. They are as follows:

• The presence of source codes and JavaDoc, i.e. must be present -sources.jarand -javadoc.jarfiles. As stated in the documentation, if it is not possible to provide source codes or documentation, you can make a dummy -sources.jaror -javadoc.jarwith a simple README inside to pass the test.
• GPG/PGP, .asc , , .
• pom
• groupId, artifactId version. -SNAPSHOT
• name, description url
• ,

, . .

build.gradle . , , , url, . :

def customizePom(pom) {
    pom.withXml {
        def root = asNode()

        root.dependencies.removeAll { dep ->
            dep.scope == "test"
        }

        root.children().last() + {
            resolveStrategy = DELEGATE_FIRST

            description 'Some description of artifact'
            name 'Artifct name'
            url 'https://github.com/login/projectname'
            organization {
                name 'com.github.login'
                url 'https://github.com/login'
            }
            issueManagement {
                system 'GitHub'
                url 'https://github.com/login/projectname/issues'
            }
            licenses {
                license {
                    name 'The Apache License, Version 2.0'
                    url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
                }
            }
            scm {
                url 'https://github.com/login/projectname'
                connection 'scm:https://github.com/login/projectname.git'
                developerConnection 'scm:git://github.com/login/projectname.git'
            }
            developers {
                developer {
                    id 'dev'
                    name 'DevName'
                    email 'email@dev.ru'
                }
            }
        }
    }
}

, -sources.jar -javadoc.jar . java :

java {
    withJavadocJar()
    withSourcesJar()
}

, GPG/PGP . signing:

plugins {
    id 'signing'
}

:

signing {
    sign publishing.publications
}

, publishing:

publishing {
    publications {
        mavenJava(MavenPublication) {
            customizePom(pom)
            groupId group
            artifactId archivesBaseName
            version version

            from components.java
        }
    }
    repositories {
        maven {
            url "https://oss.sonatype.org/service/local/staging/deploy/maven2"
            credentials {
                username sonatypeUsername
                password sonatypePassword
            }
        }
    }
}

sonatypeUsername sonatypePassword , , sonatype.org.

, build.gradle :

plugins {
    id 'java'
    id 'maven-publish'
    id 'signing'
}

java {
    sourceCompatibility = JavaVersion.VERSION_1_8
    targetCompatibility = JavaVersion.VERSION_1_8
    withJavadocJar()
    withSourcesJar()
}

group 'io.github.githublogin'
archivesBaseName = 'projectname'
version = System.getenv('RELEASE_VERSION') ?: "0.0.1"

repositories {
    mavenCentral()
}

dependencies {
    testImplementation 'org.junit.jupiter:junit-jupiter-api:5.5.2'
    testRuntimeOnly 'org.junit.jupiter:junit-jupiter-engine:5.5.2'
}

test {
    useJUnitPlatform()
}

jar {
    from sourceSets.main.output
    from sourceSets.main.allJava
}

signing {
    sign publishing.publications
}

publishing {
    publications {
        mavenJava(MavenPublication) {
            customizePom(pom)
            groupId group
            artifactId archivesBaseName
            version version

            from components.java
        }
    }
    repositories {
        maven {
            url "https://oss.sonatype.org/service/local/staging/deploy/maven2"
            credentials {
                username sonatypeUsername
                password sonatypePassword
            }
        }
    }
}

def customizePom(pom) {
    pom.withXml {
        def root = asNode()

        root.dependencies.removeAll { dep ->
            dep.scope == "test"
        }

        root.children().last() + {
            resolveStrategy = DELEGATE_FIRST

            description 'Some description of artifact'
            name 'Artifct name'
            url 'https://github.com/login/projectname'
            organization {
                name 'com.github.login'
                url 'https://github.com/githublogin'
            }
            issueManagement {
                system 'GitHub'
                url 'https://github.com/githublogin/projectname/issues'
            }
            licenses {
                license {
                    name 'The Apache License, Version 2.0'
                    url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
                }
            }
            scm {
                url 'https://github.com/githublogin/projectname'
                connection 'scm:https://github.com/githublogin/projectname.git'
                developerConnection 'scm:git://github.com/githublogin/projectname.git'
            }
            developers {
                developer {
                    id 'dev'
                    name 'DevName'
                    email 'email@dev.ru'
                }
            }
        }
    }
}

, : System.getenv('RELEASE_VERSION'). .

PGP

Sonatype GPG/PGP . GnuPG .

• : gpg --gen-key, , e-mail, .
• id : gpg --list-secret-keys --keyid-format short. Id , : rsa2048/9B695056
• https://keys.openpgp.org : gpg --keyserver https://keys.openpgp.org/ --send-keys 9B695056
• , : gpg --export-secret-key 9B695056 > D:\\gpg\\9B695056.gpg

Github Actions

, , Github Actions.
Github Actions – , , CI/CD. , : , issues. .

Sonatype , .

, id , , , PGP , / Sonatype. :

:

• SONATYPE_USERNAME/SONATYPE_PASSWORD — /, Sonatype
• SIGNING_KEYID/SIGNING_PASSWORD — id PGP , .

GPG_KEY_CONTENTS . , PGP . , , .

• gpg: gpg --symmetric --cipher-algo AES256 9B695056.gpg, . : SECRET_PASSPHRASE
• base64: base64 9B695056.gpg.gpg > 9B695056.txt. : GPG_KEY_CONTENTS.

PR

: .github/workflows.

, , gradle-ci-build.yml :

name: build

on:
  push:
    branches:
      - master
      - dev
      - testing
  pull_request:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v1
      - name: Set up JDK 8
        uses: actions/setup-java@v1
        with:
          java-version: 8

      - name: Build with Gradle
        uses: eskatos/gradle-command-action@v1
        with:
          gradle-version: current
          arguments: build -PsonatypeUsername=${{secrets.SONATYPE_USERNAME}} -PsonatypePassword=${{secrets.SONATYPE_PASSWORD}}

master, dev testing, .

jobs , . ubuntu, Java 8, Gradle eskatos/gradle-command-action@v1, , arguments. secrets.SONATYPE_USERNAME secrets.SONATYPE_PASSWORD , .

Actions:

gradle-ci-publish.yml:

name: publish

on:
  push:
    tags:
      - 'v*'

jobs:
  publish:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v1
      - name: Set up JDK 8
        uses: actions/setup-java@v1
        with:
          java-version: 8

      - name: Prepare to publish
        run: |
          echo '${{secrets.GPG_KEY_CONTENTS}}' | base64 -d > publish_key.gpg
          gpg --quiet --batch --yes --decrypt --passphrase="${{secrets.SECRET_PASSPHRASE}}" \
          --output secret.gpg publish_key.gpg
          echo "::set-env name=RELEASE_VERSION::${GITHUB_REF:11}"

      - name: Publish with Gradle
        uses: eskatos/gradle-command-action@v1
        with:
          gradle-version: current
          arguments: test publish -Psigning.secretKeyRingFile=secret.gpg -Psigning.keyId=${{secrets.SIGNING_KEYID}} -Psigning.password=${{secrets.SIGNING_PASSWORD}} -PsonatypeUsername=${{secrets.SONATYPE_USERNAME}} -PsonatypePassword=${{secrets.SONATYPE_PASSWORD}}

, . , v.

PGP , . RELEASE_VERSION gradle.build . Prepare to publish. GPG_KEY_CONTENTS, gpg , , secret.gpg.

GITHUB_REF, , . refs/tags/v0.0.2 11 , . Gradle : test publish

Sonatype

, . :

v. Publish release, , Sonatype Nexus :

Staging . Open, Close, . , Close . MavenCentral. , Release, Sonatype.

, MavenCentral, , . , . , . , MavenCentral 5 .

That's all, we published our artifact in MavenCentral.

useful links

• Similar article , only publishing via maven
• Staging Repository Sonatype
• Jira Sonatype, in which you need to create a task
• An example repository where this is all set up