= Jenkins - Nexus integration

Nexus is used to both host dependencies for devonfw projects to download (common Maven ones, custom ones such as `ojdb` and even devonfw so-far-IP modules). Moreover, it will host our projects' build artifacts (`.jar`, `.war`, ...) and expose them for us to download, wget and so on. A team should have a bidirectional relation with its Nexus repository.

== 1. Jenkins credentials to access Nexus

By default, when Nexus is installed, it contains 3 user credentials for different purposes. The admin ones look like this: `admin/admin123`. There are also other 2: `deployment/deployment123` and `TODO`.

 // ADD USER TABLE IMAGE FROM NEXUS

In this case, let's use the ones with the greater permissions: `admin/admin123`.

Go to `Credentials > System` (left sidebar of Jenkins) then to `Global credentials (unrestricted)` on the page table and on the left sidebar again click on `Add Credentials`.

This should be shown in your Jenkins:

image::./images/others/jenkins-nexus/jenkins-new-nexus-credentials.png[]

Fill the form like this:

image::./images/others/jenkins-nexus/jenkins-new-nexus-credentials-filled.png[]

And click in OK to create them. Check if the whole thing went as expected:

image::./images/others/jenkins-nexus/jenkins-new-nexus-credentials-completed.png[]

== 2. Jenkins Maven Settings

Those settings are also configured (or maybe not-yet-configured) in our *devonfw distributions* in:
```
/${devonfw-dist-path}
    /software
        /maven
            /conf
                settings.xml
```

Go to `Manage Jenkins > Managed files` and select `Add a new Config` in the left sidebar.

image::./images/others/jenkins-nexus/jenkins-new-maven-settings.png[]

The ID field will get automatically filled with a unique value if you don't set it up. No problems about that. Click on `Submit` and let's create some Servers Credentials:

image::./images/others/jenkins-nexus/jenkins-new-maven-settings-servers.png[]

Those *Server Credentials* will allow Jenkins to access to the different repositories/servers that are going to be declared afterwards.

Let's create 4 server credentials.

* `my.nexus`: Will serve as general profile for *Maven*.
* `mynexus.releases`: When a `mvn deploy` process is executed, this will tell *Maven* where to push *releases* to.
* `mynexus.snapshots`: The same as before, but with *snapshots* instead.
* `mynexus.central`: Just in case we want to install an specific dependency that is not by default in the Maven Central repository (such as `ojdbc`), Maven will point to it instead.

image::./images/others/jenkins-nexus/jenkins-new-maven-settings-servers-credentials.png[]

A more or less complete Jenkins Maven settings would look look like this:

[source,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">

    <mirrors>
        <mirror>
            <id>mynexus.central</id>
            <mirrorOf>central</mirrorOf>
            <name>central</name>
            <url>http://${URL-TO-YOUR-NEXUS-REPOS}/central</url>
        </mirror>
    </mirrors>

    <profiles>
        <profile>
            <id>my.nexus</id>
            <!-- 3 REPOS ARE DECLARED -->
            <repositories>
                <repository>
                    <id>mynexus.releases</id>
                    <name>mynexus Releases</name>
                    <url>http://${URL-TO-YOUR-NEXUS-REPOS}/releases</url>
                    <releases>
                        <enabled>true</enabled>
                        <updatePolicy>always</updatePolicy>
                    </releases>
                    <snapshots>
                        <enabled>false</enabled>
                        <updatePolicy>always</updatePolicy>
                    </snapshots>
                </repository>
                <repository>
                    <id>mynexus.snapshots</id>
                    <name>mynexus Snapshots</name>
                    <url>http://${URL-TO-YOUR-NEXUS-REPOS}/snapshots</url>
                    <releases>
                        <enabled>false</enabled>
                        <updatePolicy>always</updatePolicy>
                    </releases>
                    <snapshots>
                        <enabled>true</enabled>
                        <updatePolicy>always</updatePolicy>
                    </snapshots>
                </repository>
            </repositories>
            <pluginRepositories>
                <pluginRepository>
                    <id>public</id>
                    <name>Public Repositories</name>
                    <url>http://${URL-TO-YOUR-NEXUS}/nexus/content/groups/public/</url>
                    <releases>
                        <enabled>true</enabled>
                        <updatePolicy>always</updatePolicy>
                    </releases>
                    <snapshots>
                        <enabled>true</enabled>
                        <updatePolicy>always</updatePolicy>
                    </snapshots>
                </pluginRepository>
            </pluginRepositories>
        </profile>
    </profiles>
    <!-- HERE IS WHERE WE TELL MAVEN TO CHOOSE THE my.nexus PROFILE -->
    <activeProfiles>
        <activeProfile>my.nexus</activeProfile>
    </activeProfiles>
</settings>
----

== 3. Use it in Jenkins Pipelines