feat(crd-generator): Add CRD-Generator CLI

[baloo42]

Description

Fixes #5958
Relates to #5950

Add CRD-Generator CLI application (using api-v2).

Usage:

crd-gen [-hVv] [--force-index] [--force-scan] [--implicit-preserve-unknown-fields] [--no-parallel]
        [-o=<outputDirectory>] [-cp=<classpathElement>]... [--exclude-package=<package>]...
        [--include-package=<package>]... <source>...

Description:

Fabric8 CRD-Generator
Generate Custom Resource Definitions (CRD) for Kubernetes from Java classes.

Parameters:
      <source>...     A directory or JAR file to scan for Custom Resource classes, or a full qualified Custom Resource
                        class name.

Options:
  -o, --output-dir=<outputDirectory>
                      The output directory where the CRDs are emitted.
                        Default: .
      -cp, --classpath=<classpathElement>
                      Additional classpath element, e.g. a dependency packaged as JAR file or a directory of class
                        files.
      --force-index   Create Jandex index even if the directory or JAR file contains an existing index.
      --force-scan    Scan directories and JAR files even if Custom Resource classes are given.
      --no-parallel   Disable parallel generation of CRDs.
      --implicit-preserve-unknown-fields
                      `x-kubernetes-preserve-unknown-fields: true` will be added on objects which contain an any-setter
                        or any-getter.
      --include-package=<package>
                      Filter Custom Resource classes after scanning by package inclusions.
      --exclude-package=<package>
                      Filter Custom Resource classes after scanning by package exclusions.
  -v                  Verbose mode. Helpful for troubleshooting.
                      Multiple -v options increase the verbosity.
  -h, --help          Show this help message and exit.
  -V, --version       Print version information and exit.

Exit Codes:
   0   Successful execution
   1   Unexpected error
   2   Invalid input
  70   Custom Resource class loading failed
  80   No Custom Resource classes retained after filtering

Examples:
  Generate CRDs for Custom Resource classes in a directory:
    crd-gen target/classes/
  Generate CRDs for Custom Resource classes in a JAR file:
    crd-gen my-jar-with-custom-resources.jar
  Generate CRD by using a single class only:
    crd-gen -cp target/classes/ com.example.MyCustomResource

Type of change

• Bug fix (non-breaking change which fixes an issue)
• Feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change
• Chore (non-breaking change which doesn't affect codebase;
  test, version modification, documentation, etc.)

Checklist

• Code contributed by me aligns with current project license: Apache 2.0
• I Added CHANGELOG entry regarding this change
• I have implemented unit tests to cover my changes
• I have added/updated the javadocs and other documentation accordingly
• No new bugs, code smells, etc. in SonarCloud report

[manusa]

This seems fine to me,
@metacosm @andreaTP, @shawkins any additional comments?

[baloo42]

@manusa Thanks for looking into this.

I added some comments where I'm not sure if it's done right.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
91.3% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud