ORAN Developer's Guide to CI Resources and Processes at the LF

This is a guide for software developers and testers about the continuous integration (CI) resources and processes used by the project and supported by the Linux Foundation.

Continuous Integration Network Resources

Most of these resources authenticate users via a Linux Foundation identity.

Development Procedures and Policies

This section guides the developer in submitting code, reviewing code, tracking the status of builds and requesting creation of release versions. These recommended practices come from the Linux Foundation.

Always create a branch

When working with a git repository cloned from Gerrit you can create as many local branches as you like.  None of the branches will be pushed to the remote Gerrit server, the branches remain forever private.  Creating branches for each task will allow you to work on multiple independent tasks in parallel, let you recover gracefully from various situations, and generally save aggravation and time. Also see these instructions on tagging and branching for releases:

Tagging and Branching Steps Process

Write good git commit messages

The Linux Foundation strongly recommends (and eventually may enforce) Gerrit commit message content. A git commit message must meet these requirements:

1. The first line should have a short change summary, up to 50 characters
2. The second line must be blank
3. The body of the commit message should have a detailed change description, wrap lines at 72 characters max
4. The line before the footer must be blank
5. The footer (last block of lines following a blank line) must consist of these lines:
   1. Issue-ID: line with a valid Jira issue number, composed and inserted manually by the committer
   2. Change-Id: line, which is automatically generated and inserted by git review
   3. Signed-off-by line, which is automatically generated and inserted by git commit

An example is shown below:

Null check for ClientResponse

NullPointerException might be thrown as cres is nullable here

Issue-Id: PROJECT-999
Change-Id: I14dc792fb67198ebcbabfe80d90c48389af6cc91
Signed-off-by: First Last <fl1234567890@my-company.com>

Please note that the Jira system's pattern matcher that finds issue IDs in Gerrit reviews is extremely limited.  The "Issue-Id" line must be EXACTLY as shown above! The keyword must be written in mixed case as shown, then a colon, then a space, then the appropriate project name in ALL CAPS, then a hyphen, then the number.

Working with Docker images

The docker image name is set by the Jenkins job, as configured by the JJB. The method for choosing the docker image tag is also configured in the Jenkins job, one of the following:

• "latest": This constant string is always used
• "git-describe": The output of the "git describe" command is used. This requires that the repository has at least one git  tag.
  
• "yaml-file": The file container-tag.yaml in the project repository is queried for the entry with key "tag"

For the non-constant options, the development team must manage the tag or the version string in the YAML file.

The Jenkins verify job creates a docker image to test the creation process, then discards the image at completion.

The Jenkins merge job creates a docker image and pushes the image to the staging registry.Jenkins job sets the PUSH registry to STAGING.

Creation of a final release image requires opening a ticket with LF release-engineering team.  They sign the image found in the staging registry and move it manually to the release registry.

Using Gerrit

The project uses Gerrit to automate the process of reviewing all code changes before they are committed to the Git repository. For a tutorial on git you might start here:

https://git-scm.com/doc

Also see this guide published by the LF Release Engineering team about using Gerrit:

https://docs.releng.linuxfoundation.org/en/latest/gerrit.html

Prohibited Content

Gerrit is designed to host text files – source code.  It enforces a size threshold on every commit, the default limit is 5MB.  Further the Linux Foundation prohibits committing binary files such as compiled executables, jar files, zip archives and so on. An exception is made for binary picture (image) files in GIF, JPG and PNG formats, but the size limit must still be honored.

Quickstart Guides

The quickstart guides below describe the command-line procedures for performing common tasks on Gerrit.  The command-line tool "git review" is the most reliable and can be used on any platform.  Windows users should install "Git Bash" to gain support for command-line git.

Quickstart: Create and submit a change for review

git checkout -b my-local-branch
# work work work
git commit -as
    # Write a commit message including a line "Issue-ID:" with Jira ticket nr
git review master

Quickstart: Submit a change to a branch other than "master"

git review other-branch

Quickstart: Revise your open gerrit review

git checkout my-local-branch
# revise revise revise
git commit -a --amend
    # Revise your message but do NOT alter the Change-Id: line
git review master

Quickstart: Revise any open gerrit review

# Look up the change number shown top-left in Gerrit web, here "999".
git review -d 999
# revise revise revise
git commit -a --amend
    # Check your message -- do NOT alter the Change-Id: line
git review --no-rebase master

Quickstart: Resolve a conflicted review

git checkout master
git pull origin master
# Look up the change number in Gerrit, it's shown top-left, here 999
git review -d 999
git rebase master
# fix conflicts
git add .
git rebase --continue
git review master

Quickstart: Squash commits after you forgot the "--amend" flag

# count number of commits to be squashed, the 2 below is for two
git reset --soft HEAD~2
git commit

Reviewing and merging changes

Submitted reviews with changes should appear in the Gerrit web interface. The Jenkins job builder will publish test results, giving "Verified +1" if the test succeeds and -1 if the test fails.  A contributor or committer can review it with a -1/0/+1. A committer then must approve it with a +2 rating and merge the code to the master branch.

The committer may take any of several actions, such as clicking on the "Reply" button, adding reviewers, adding a review comment, and moving the flags to +2 and +1

Once a committer/contributor approves it, the code can be merged to the master branch.

Create a Git branch or tag

A project committer can create a branch at any time using the Gerrit web site. Similarly a project committer can add a tag to the repository using the Gerrit web site. To reach the administration screen for a repository, start with the "Browse" menu at the top, pick Repositories, find the repository in the list and click on its link. To create a branch, pick "Branches" on the left side, then click the Create New button, as shown in the screen shot below. Similarly to create a tag, from the administration screen for the repository pick "Tags" on the left side, then click the Create New button (screen not shown).

Triggering Jenkins jobs from Gerrit

Most Jenkins jobs can be launched by posting a comment in the Gerrit system on a review. The exact string that is required depends on the job type.

• Post "recheck" to re-run a verify job.  This may be necessary due to intermittent network failures at Jenkins, because a dependency has become available, etc.
• Post "remerge" to re-run a merge job.  This may be necessary due to intermittent network failures at Jenkins, to recreate a version of an artifact, etc.
• Post "run-sonar" to run the Sonar analysis job (if applicable).
• Post "jjb-deploy <pattern>" on a ci-management change to create jobs matching the pattern (for example "myproject-*") to the Jenkins sandbox.

Releasing Binary Artifacts

In the LF environment, "to release" means to promote an artifact from an ephemeral staging area to a permanent release area. For example, move a Docker image from a Nexus staging registry where images are deleted after two weeks to a Nexus release registry where images are kept "forever." This self-service process is implemented by Jenkins jobs that react to files committed and merged via Gerrit. Guarding the process with the Gerrit merge task means only committers can release artifacts.

Once testing against the staging repo version has been completed (see above ) and the project has determined that the artifact in the staged repository is ready for release, the project team can use the new-for-2019 self-release process. For details on the JJB templates please see https://docs.releng.linuxfoundation.org/projects/global-jjb/en/latest/jjb/lf-release-jobs.html

Releasing a Java/maven artifact

1. Find the Jenkins stage job that created the release candidate.  Look among its output logs for the file with the name: staging-repo.txt.gz, it will have a URL like this:
   1. https://logs.acumos.org/production/vex-yul-acumos-jenkins-1/common-dataservice-maven-dl-stage-master/4/staging-repo.txt.gz
2. Create a new release yaml file in the directory "releases/" at the repo root.
   
   1. The file name should be anything, but most projects use a pattern like "release-maven.yaml". An example of the content appears below.
   2. The file content has the project name, the version to release, and the log directory you found above, altho in abbreviated form.
3. Create a new change set with just the new file, commit to git locally and submit the change set to Gerrit.
4. After the verify job succeeds, a project committer should merge the change set. This will tag the repository with the version string AND release the artifact.

Example release yaml file content:

---
distribution_type: maven
version: 1.0.0
project: example-project
log_dir: example-project-maven-stage-master/17/

After the release merge job runs to completion, the jar files should appear in the Nexus2 release repository.

Releasing a Docker artifact

For a Docker image the release yaml file must list the desired release tag and the existing container tags. Example release yaml file content:

distribution_type: container
container_release_tag: 1.0.0
container_pull_registry: nexus.o-ran-sc.org:10003
container_push_registry: nexus.o-ran-sc.org:10002
project: test
ref: b95b07641ead78b5082484aa8a82c900f79c9706
containers:
    - name: test-backend
      version: 1.0.0-20190806T184921Z
    - name: test-frontend
      version: 1.0.0-20190806T184921Z

After the release merge job runs to completion, the container images should appear in the Nexus3 release registry.

Releasing a Python package

For a Python package the release yaml file must list the log directory, python version and more. Example release yaml file content:

---
distribution_type: pypi
log_dir: ric-plt-lib-rmr-python-pypi-merge-master/1
pypi_project: rmr
python_version: '3.7'
version: 1.0.0
project: myproject

If you use a valid decimal value anywhere (like 3.7 above), put it in single quotes so it can be parsed as a string, not a number.

After the release merge job runs to completion, the packages should appear in the https://pypi.org index.

Releasing a PackageCloud DEB/RPM package

The self-release process for PackageCloud is in active development as of December 2019. Until it is ready, write a ticket at https://jira.linuxfoundation.org/servicedesk

Jenkins Job Builder Templates

All jobs in the Jenkins server are generated from Jenkins Job Builder (JJB) templates. The templates are maintained in the "ci-management" git repository.  A project template is defined for each project in a YAML file (e.g., "com-log.yaml").  The project templates use job templates defined by the Linux Foundation Global JJB as well as job templates custom to this project.

Setting up development environment

Making Java code checked by Sonar

To make Java code checked by Sonar an addition to the projects pom file is needed, see below.

<plugin>
    <groupId>org.sonarsource.scanner.maven</groupId>
    <artifactId>sonar-maven-plugin</artifactId>
    <version>${sonar-maven-plugin.version}</version>
</plugin>
<plugin>
    <groupId>org.jacoco</groupId>
    <artifactId>jacoco-maven-plugin</artifactId>
    <version>0.8.4</version>
    <executions>
        <execution>
            <id>default-prepare-agent</id>
            <goals>
                <goal>prepare-agent</goal>
            </goals>
        </execution>
        <execution>
            <id>default-report</id>
            <phase>prepare-package</phase>
            <goals>
                <goal>report</goal>
            </goals>
        </execution>
    </executions>
</plugin>

Then the Jenkins job needs to be updated, see the following commit for an example: https://gerrit.o-ran-sc.org/r/c/ci-management/+/2446.

Setting up Eclipse for Sonar

To be able to connect Eclipse to Sonar, the SonarLint plugin is needed. To install this plugin, follow the steps below:

1. In Eclipse, open the "Help → Eclipse Marketplace...".
2. In the "Find:" box, type "sonarlint" and press "Go".
3. The latest version of SonarLint should show up at the top of the search results. Press the "Install" button.
4. Accept license and restart Eclipse after installation is finished.

When SonarLint is installed, it should be connected to the SonarCloud and bound to the project. To do this, follow the steps below:

1. In Eclipse, right click on the project and select "SonarLint → Bind to SonarQube or SonarCloud...".
2. In the dialog, press the "New" button.
3. Make sure the "sonarcloud" radio button is selected and press "Next".
4. If you do not have a token generated in SonarCloud, press the "Generate token" button. Otherwise you can reuse yor token.
5. Follow the instructions in the web page you are redirected to to generate the token.
6. Paste the token in to the "Token:" box and press "Next".
7. In the "Organization:" box, type "o-ran-sc" and press "Next".
8. Press "Next".
9. Press "Finish".
10. Select "Window → Show View → Other..." and then "SonarLint bindings".
11. In the view, doubleclick the new binding.
12. In the dialog, Press "Add", select the project to bind, press "Ok", and press "Next".
13. Type your project's name. When it show up in the result list, select it and press "Finish".

Now Sonar issues should show up in your code.

Note! At the moment there is a bug that show up if Lombok is used in the code. To see when a fix is released, follow this link Lombok issue.