https://github.com/snowdrop/istio-java-api

A Java API to generate Istio descriptors, inspired by Fabric8's kubernetes-model.
https://github.com/snowdrop/istio-java-api

api code-generator golang istio java kubernetes

Last synced: about 1 month ago
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A Java API to generate Istio descriptors, inspired by Fabric8's kubernetes-model.

• Host: GitHub
• URL: https://github.com/snowdrop/istio-java-api
• Owner: snowdrop
• License: apache-2.0
• Archived: true
• Created: 2017-12-05T20:52:34.000Z (almost 7 years ago)
• Default Branch: master
• Last Pushed: 2022-03-29T21:06:30.000Z (over 2 years ago)
• Last Synced: 2024-06-18T21:43:15.637Z (5 months ago)
• Topics: api, code-generator, golang, istio, java, kubernetes
• Language: Java
• Size: 17.8 MB
• Stars: 112
• Watchers: 9
• Forks: 33
• Open Issues: 17
• Metadata Files:
  • Readme: README.adoc
  • License: LICENSE

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README

        
**Note**

= This project is now deprecated. Please use the Istio client in the https://github.com/fabric8io/kubernetes-client project starting with version 5.11.0.

= istio-java-api

A project to generate a Java API for https://istio.io[Istio]'s domain allowing, in particular, the generation of Istio deployment

descriptors.This project is inspired by https://github.com/fabric8io/kubernetes-model[Fabric8's kubernetes-model] and relies on

the same approach: a Go program uses Go reflection to generate a http://json-schema.org[JSON Schema] which is then used by

https://github.com/joelittlejohn/jsonschema2pojo[jsonschema2pojo] to generate Java classes. jsonschema2pojo is configured to use

a custom annotator, `IstioTypeAnnotator` (found in the `istio-model-annotator` module), to add

(https://github.com/fasterxml/jackson[Jackson], https://jcp.org/en/jsr/detail?id=380[Bean Validation - JSR 380] and

https://github.com/sundrio/sundrio[sundrio] annotations.Sundrio is used generate idiomatic builder and DSL Java classes.

Jackson is used to output JSON or YAML representation of the Java objects when needed.

== Usage

Please take a look at the tests in `istio-model/src/test/java` to see how the API can be used.

You can also take a look at the

https://github.com/metacosm/istio-test-dsl project which demonstrates an end-to-end scenario using the Fabric8 OpenShift adapter and this API to send Istio artifacts to a running OpenShift cluster configured on which Istio is set up.

[Note]

====

Starting with the `1.7.7` of this API, the bundled version of the Fabric8 Kubernetes client has been upgraded to use the non-backwards compatible `5.x` versions.

While this might not be an issue for most users of this API, it's still worth noting.

====

== Building instructions

If you only want to build the current version of the API and don't intend on modifying how the JSON Schema is generated, you can build simply using `mvn clean install` as the project contains a pre-generated version of the schema.If you need to re-generate the classes from a newer version of the API, since the build relies on Go introspection, you will need to set up a Go programming environment.

=== Building the Java API

You will need to https://golang.org/doc/install[install Go] and `make`.

Run `make`.

This will build the `generate` command line tool from Go and then run it to generate a JSON Schema in

`istio-model/src/main/resources/schema/istio-schema.json`.

A Maven build is then issued using the `jsonschema2pojo` Maven plugin to generate Java classes in `istio-model/target/generated-sources` and generate a Jar file containing the compiled version of these classes along with the JSON schema, ready to be used.

You can *clean* everything using `make clean`, only *generate the schema* using `make schema` or only generate the Java classes from an already generated schema such as the provided one using `mvn clean install`.

=== Updating the Java API when Istio is updated

NOTE: The process is not completely reproducible at this time.

:(

[source,bash]

----

# update to the latest istio version, rebuild crd list and packages

make metadata

# build using strict mode

make strict

# fix any issue, iterate… :)

----

You can also re-generate the properties files that are used to determine which

https://kubernetes.io/docs/concepts/extend-kubernetes/api-extension/custom-resources/[Kubernetes Custom Resource Definitions (CRDs)]

are specified by Istio.

These files are located in `istio-common/src/main/resources/`, one for each kind of supported CRDs and can be generated using `make metadata`.

You can also re-generate the CSV file that is used to map Istio Go packages to Java packages.

The file is located at

`istio-common/src/main/resources/packages.csv` and can be generated using `make metadata`.