Merge branch '33329-tech-article-deploying-maven-artifacts' into 'master'

Resolve "Tech article: Deploying Maven artifacts"

Closes #33329

See merge request !11955

7 files changed, 285 insertions, 4 deletions

diff --git a/doc/README.md b/doc/README.md
index 4175750d497..547541c4876 100644
--- a/doc/README.md
+++ b/doc/README.md
@@ -32,6 +32,7 @@ Shortcuts to GitLab's most visited docs:
 
 - [User documentation](user/index.md)
 - [Administrator documentation](#administrator-documentation)
+- [Technical Articles](articles/index.md)
 
 ## Getting started with GitLab
 
diff --git a/doc/articles/artifactory_and_gitlab/index.md b/doc/articles/artifactory_and_gitlab/index.md
new file mode 100644
index 00000000000..c64851bad2b
--- /dev/null
+++ b/doc/articles/artifactory_and_gitlab/index.md
@@ -0,0 +1,278 @@
+# How to deploy Maven projects to Artifactory with GitLab CI/CD
+
+> **Article [Type](../../development/writing_documentation.md#types-of-technical-articles):** tutorial ||
+> **Level:** intermediary ||
+> **Author:** [Fabio Busatto](https://gitlab.com/bikebilly) ||
+> **Publication date:** 2017-08-15
+
+## Introduction
+
+In this article, we will show how you can leverage the power of [GitLab CI/CD](https://about.gitlab.com/features/gitlab-ci-cd/)
+to build a [Maven](https://maven.apache.org/) project, deploy it to [Artifactory](https://www.jfrog.com/artifactory/), and then use it from another Maven application as a dependency.
+
+You'll create two different projects:
+
+- `simple-maven-dep`: the app built and deployed to Artifactory (available at https://gitlab.com/gitlab-examples/maven/simple-maven-dep)
+- `simple-maven-app`: the app using the previous one as a dependency (available at https://gitlab.com/gitlab-examples/maven/simple-maven-app)
+
+We assume that you already have a GitLab account on [GitLab.com](https://gitlab.com/), and that you know the basic usage of Git and [GitLab CI/CD](https://about.gitlab.com/features/gitlab-ci-cd/).
+We also assume that an Artifactory instance is available and reachable from the internet, and that you have valid credentials to deploy on it.
+
+## Create the simple Maven dependency
+
+First of all, you need an application to work with: in this specific case we will
+use a simple one, but it could be any Maven application. This will be the
+dependency you want to package and deploy to Artifactory, in order to be
+available to other projects.
+
+### Prepare the dependency application
+
+For this article you'll use a Maven app that can be cloned from our example
+project:
+
+1. Log in to your GitLab account
+1. Create a new project by selecting **Import project from ➔ Repo by URL**
+1. Add the following URL:
+
+    ```
+    https://gitlab.com/gitlab-examples/maven/simple-maven-dep.git
+    ```
+1. Click **Create project**
+
+This application is nothing more than a basic class with a stub for a JUnit based test suite.
+It exposes a method called `hello` that accepts a string as input, and prints a hello message on the screen.
+
+The project structure is really simple, and you should consider these two resources:
+
+- `pom.xml`: project object model (POM) configuration file
+- `src/main/java/com/example/dep/Dep.java`: source of our application
+
+### Configure the Artifactory deployment
+
+The application is ready to use, but you need some additional steps to deploy it to Artifactory:
+
+1. Log in to Artifactory with your user's credentials.
+1. From the main screen, click on the `libs-release-local` item in the **Set Me Up** panel.
+1. Copy to clipboard the configuration snippet under the **Deploy** paragraph.
+1. Change the `url` value in order to have it configurable via secret variables.
+1. Copy the snippet in the `pom.xml` file for your project, just after the
+   `dependencies` section. The snippet should look like this:
+
+    ```xml
+    <distributionManagement>
+      <repository>
+        <id>central</id>
+        <name>83d43b5afeb5-releases</name>
+        <url>${env.MAVEN_REPO_URL}/libs-release-local</url>
+      </repository>
+    </distributionManagement>
+    ```
+
+Another step you need to do before you can deploy the dependency to Artifactory
+is to configure the authentication data. It is a simple task, but Maven requires
+it to stay in a file called `settings.xml` that has to be in the `.m2` subdirectory
+in the user's homedir.
+
+Since you want to use GitLab Runner to automatically deploy the application, you
+should create the file in the project's home directory and set a command line
+parameter in `.gitlab-ci.yml` to use the custom location instead of the default one:
+
+1. Create a folder called `.m2` in the root of your repository
+1. Create a file called `settings.xml` in the `.m2` folder
+1. Copy the following content into a `settings.xml` file:
+
+    ```xml
+    <settings xsi:schemaLocation="http://maven.apache.org/SETTINGS/1.1.0 http://maven.apache.org/xsd/settings-1.1.0.xsd"
+        xmlns="http://maven.apache.org/SETTINGS/1.1.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
+      <servers>
+        <server>
+          <id>central</id>
+          <username>${env.MAVEN_REPO_USER}</username>
+          <password>${env.MAVEN_REPO_PASS}</password>
+        </server>
+      </servers>
+    </settings>
+    ```
+
+    Username and password will be replaced by the correct values using secret variables.
+
+### Configure GitLab CI/CD for `simple-maven-dep`
+
+Now it's time we set up [GitLab CI/CD](https://about.gitlab.com/features/gitlab-ci-cd/) to automatically build, test and deploy the dependency!
+
+GitLab CI/CD uses a file in the root of the repo, named `.gitlab-ci.yml`, to read the definitions for jobs
+that will be executed by the configured GitLab Runners. You can read more about this file in the [GitLab Documentation](https://docs.gitlab.com/ee/ci/yaml/).
+
+First of all, remember to set up secret variables for your deployment. Navigate to your project's **Settings > CI/CD** page
+and add the following secret variables (replace them with your current values, of course):
+
+- **MAVEN_REPO_URL**: `http://artifactory.example.com:8081/artifactory` (your Artifactory URL)
+- **MAVEN_REPO_USER**: `gitlab` (your Artifactory username)
+- **MAVEN_REPO_PASS**: `AKCp2WXr3G61Xjz1PLmYa3arm3yfBozPxSta4taP3SeNu2HPXYa7FhNYosnndFNNgoEds8BCS` (your Artifactory Encrypted Password)
+
+Now it's time to define jobs in `.gitlab-ci.yml` and push it to the repo:
+
+```yaml
+image: maven:latest
+
+variables:
+  MAVEN_CLI_OPTS: "-s .m2/settings.xml --batch-mode"
+  MAVEN_OPTS: "-Dmaven.repo.local=.m2/repository"
+
+cache:
+  paths:
+    - .m2/repository/
+    - target/
+
+build:
+  stage: build
+  script:
+    - mvn $MAVEN_CLI_OPTS compile
+
+test:
+  stage: test
+  script:
+    - mvn $MAVEN_CLI_OPTS test
+
+deploy:
+  stage: deploy
+  script:
+    - mvn $MAVEN_CLI_OPTS deploy
+  only:
+    - master
+```
+
+GitLab Runner will use the latest [Maven Docker image](https://hub.docker.com/_/maven/), which already contains all the tools and the dependencies you need to manage the project,
+in order to run the jobs.
+
+Environment variables are set to instruct Maven to use the `homedir` of the repo instead of the user's home when searching for configuration and dependencies.
+
+Caching the `.m2/repository folder` (where all the Maven files are stored), and the `target` folder (where our application will be created), is useful for speeding up the process
+by running all Maven phases in a sequential order, therefore, executing `mvn test` will automatically run `mvn compile` if necessary.
+
+Both `build` and `test` jobs leverage the `mvn` command to compile the application and to test it as defined in the test suite that is part of the application.
+
+Deploy to Artifactory is done as defined by the secret variables we have just set up.
+The deployment occurs only if we're pushing or merging to `master` branch, so that the development versions are tested but not published.
+
+Done! Now you have all the changes in the GitLab repo, and a pipeline has already been started for this commit. In the **Pipelines** tab you can see what's happening.
+If the deployment has been successful, the deploy job log will output:
+
+```
+[INFO] ------------------------------------------------------------------------
+[INFO] BUILD SUCCESS
+[INFO] ------------------------------------------------------------------------
+[INFO] Total time: 1.983 s
+```
+
+>**Note**:
+the `mvn` command downloads a lot of files from the internet, so you'll see a lot of extra activity in the log the first time you run it.
+
+Yay! You did it! Checking in Artifactory will confirm that you have a new artifact available in the `libs-release-local` repo.
+
+## Create the main Maven application
+
+Now that you have the dependency available on Artifactory, it's time to use it!
+Let's see how we can have it as a dependency to our main application.
+
+### Prepare the main application
+
+We'll use again a Maven app that can be cloned from our example project:
+
+1. Create a new project by selecting **Import project from ➔ Repo by URL**
+1. Add the following URL:
+
+    ```
+    https://gitlab.com/gitlab-examples/maven/simple-maven-app.git
+    ```
+1. Click **Create project**
+
+This one is a simple app as well. If you look at the `src/main/java/com/example/app/App.java`
+file you can see that it imports the `com.example.dep.Dep` class and calls the `hello` method passing `GitLab` as a parameter.
+
+Since Maven doesn't know how to resolve the dependency, you need to modify the configuration:
+
+1. Go back to Artifactory
+1. Browse the `libs-release-local` repository
+1. Select the `simple-maven-dep-1.0.jar` file
+1. Find the configuration snippet from the **Dependency Declaration** section of the main panel
+1. Copy the snippet in the `dependencies` section of the `pom.xml` file.
+   The snippet should look like this:
+
+    ```xml
+    <dependency>
+      <groupId>com.example.dep</groupId>
+      <artifactId>simple-maven-dep</artifactId>
+      <version>1.0</version>
+    </dependency>
+    ```
+
+### Configure the Artifactory repository location
+
+At this point you defined the dependency for the application, but you still miss where you can find the required files.
+You need to create a `.m2/settings.xml` file as you did for the dependency project, and let Maven know the location using environment variables.
+
+Here is how you can get the content of the file directly from Artifactory:
+
+1. From the main screen, click on the `libs-release-local` item in the **Set Me Up** panel
+1. Click on **Generate Maven Settings**
+1. Click on **Generate Settings**
+1. Copy to clipboard the configuration file
+1. Save the file as `.m2/settings.xml` in your repo
+
+Now you are ready to use the Artifactory repository to resolve dependencies and use `simple-maven-dep` in your main application!
+
+### Configure GitLab CI/CD for `simple-maven-app`
+
+You need a last step to have everything in place: configure the `.gitlab-ci.yml` file for this project, as you already did for `simple-maven-dep`.
+
+You want to leverage [GitLab CI/CD](https://about.gitlab.com/features/gitlab-ci-cd/) to automatically build, test and run your awesome application,
+and see if you can get the greeting as expected!
+
+All you need to do is to add the following `.gitlab-ci.yml` to the repo:
+
+```yaml
+image: maven:latest
+
+stages:
+  - build
+  - test
+  - run
+
+variables:
+  MAVEN_CLI_OPTS: "-s .m2/settings.xml --batch-mode"
+  MAVEN_OPTS: "-Dmaven.repo.local=.m2/repository"
+
+cache:
+  paths:
+    - .m2/repository/
+    - target/
+
+build:
+  stage: build
+  script:
+    - mvn $MAVEN_CLI_OPTS compile
+
+test:
+  stage: test
+  script:
+    - mvn $MAVEN_CLI_OPTS test
+
+run:
+  stage: run
+  script:
+    - mvn $MAVEN_CLI_OPTS package
+    - mvn $MAVEN_CLI_OPTS exec:java -Dexec.mainClass="com.example.app.App"
+```
+
+It is very similar to the configuration used for `simple-maven-dep`, but instead of the `deploy` job there is a `run` job.
+Probably something that you don't want to use in real projects, but here it is useful to see the application executed automatically.
+
+And that's it! In the `run` job output log you will find a friendly hello to GitLab!
+
+## Conclusion
+
+In this article we covered the basic steps to use an Artifactory Maven repository to automatically publish and consume artifacts.
+
+A similar approach could be used to interact with any other Maven compatible Binary Repository Manager.
+Obviously, you can improve these examples, optimizing the `.gitlab-ci.yml` file to better suit your needs, and adapting to your workflow.
diff --git a/doc/articles/how_to_configure_ldap_gitlab_ce/index.md b/doc/articles/how_to_configure_ldap_gitlab_ce/index.md
index 130e8f542b4..25a24bc1d32 100644
--- a/doc/articles/how_to_configure_ldap_gitlab_ce/index.md
+++ b/doc/articles/how_to_configure_ldap_gitlab_ce/index.md
@@ -3,7 +3,7 @@
 > **Article [Type](../../development/writing_documentation.html#types-of-technical-articles):** admin guide ||
 > **Level:** intermediary ||
 > **Author:** [Chris Wilson](https://gitlab.com/MrChrisW) ||
-> **Publication date:** 2017/05/03
+> **Publication date:** 2017-05-03
 
 ## Introduction
 
diff --git a/doc/articles/how_to_install_git/index.md b/doc/articles/how_to_install_git/index.md
index 66d866b2d09..37b60501ce2 100644
--- a/doc/articles/how_to_install_git/index.md
+++ b/doc/articles/how_to_install_git/index.md
@@ -3,7 +3,7 @@
 > **Article [Type](../../development/writing_documentation.html#types-of-technical-articles):** user guide ||
 > **Level:** beginner ||
 > **Author:** [Sean Packham](https://gitlab.com/SeanPackham) ||
-> **Publication date:** 2017/05/15
+> **Publication date:** 2017-05-15
 
 To begin contributing to GitLab projects
 you will need to install the Git client on your computer.
diff --git a/doc/articles/index.md b/doc/articles/index.md
index 558c624fe39..3039faca411 100644
--- a/doc/articles/index.md
+++ b/doc/articles/index.md
@@ -26,6 +26,7 @@ Build, test, and deploy the software you develop with [GitLab CI/CD](../ci/READM
 
 | Article title | Category | Publishing date |
 | :------------ | :------: | --------------: |
+| [How to deploy Maven projects to Artifactory with GitLab CI/CD](artifactory_and_gitlab/index.md) | Tutorial | 2017-08-15 |
 | [Making CI Easier with GitLab](https://about.gitlab.com/2017/07/13/making-ci-easier-with-gitlab/) | Concepts | 2017/07/13 |
 | [Dockerizing GitLab Review Apps](https://about.gitlab.com/2017/07/11/dockerizing-review-apps/) | Concepts | 2017/07/11 |
 | [Continuous Integration: From Jenkins to GitLab Using Docker](https://about.gitlab.com/2017/07/27/docker-my-precious/) | Concepts | 2017/07/27 |
diff --git a/doc/articles/openshift_and_gitlab/index.md b/doc/articles/openshift_and_gitlab/index.md
index 7f76e577efa..c0bbcfe2a8a 100644
--- a/doc/articles/openshift_and_gitlab/index.md
+++ b/doc/articles/openshift_and_gitlab/index.md
@@ -3,7 +3,7 @@
 > **Article [Type](../../development/writing_documentation.html#types-of-technical-articles):** tutorial ||
 > **Level:** intermediary ||
 > **Author:** [Achilleas Pipinellis](https://gitlab.com/axil) ||
-> **Publication date:** 2016/06/28
+> **Publication date:** 2016-06-28
 
 ## Introduction
 
diff --git a/doc/ci/README.md b/doc/ci/README.md
index 10ea9467942..c722d895f42 100644
--- a/doc/ci/README.md
+++ b/doc/ci/README.md
@@ -111,7 +111,8 @@ Here is an collection of tutorials and guides on setting up your CI pipeline.
   - [Phoenix](examples/test-phoenix-application.md)
   - [Run PHP Composer & NPM scripts then deploy them to a staging server](examples/deployment/composer-npm-deploy.md)
   - [Analyze code quality with the Code Climate CLI](examples/code_climate.md)
-- **Blog posts**
+- **Articles**
+  - [How to deploy Maven projects to Artifactory with GitLab CI/CD](../articles/artifactory_and_gitlab/index.md)
   - [Automated Debian packaging](https://about.gitlab.com/2016/10/12/automated-debian-package-build-with-gitlab-ci/)
   - [Spring boot application with GitLab CI and Kubernetes](https://about.gitlab.com/2016/12/14/continuous-delivery-of-a-spring-boot-application-with-gitlab-ci-and-kubernetes/)
   - [Setting up GitLab CI for iOS projects](https://about.gitlab.com/2016/03/10/setting-up-gitlab-ci-for-ios-projects/)