Skip to content
Java annotation processors for Kubernetes
Java
Branch: master
Clone or download
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
.circleci fix: include clean in the OPENSHIFT job. Jul 11, 2019
annotations fix: remove unsupported type Aug 20, 2019
core [maven-release-plugin] prepare for next development iteration Aug 18, 2019
dependencies [maven-release-plugin] prepare for next development iteration Aug 18, 2019
doc [maven-release-plugin] prepare for next development iteration Aug 18, 2019
examples fix: use proper 0.8-SNAPSHOT version Aug 19, 2019
frameworks [maven-release-plugin] prepare for next development iteration Aug 18, 2019
incubator fix: use proper 0.8-SNAPSHOT version Aug 19, 2019
starters [maven-release-plugin] prepare for next development iteration Aug 18, 2019
testing [maven-release-plugin] prepare for next development iteration Aug 18, 2019
.editorconfig
.gitignore chore: add .factorypath to gitignore. Jul 11, 2019
_config.yml Set theme jekyll-theme-tactile Jun 24, 2019
config.md doc: Fix broken tables and elaborate on complex object handling. Jul 25, 2019
contributor-guidelines.md doc: fix description Aug 14, 2019
design.md refactor: revert HalkyonConfig to ComponentConfig Aug 14, 2019
header.txt feat: Add Capability annotation. Jul 11, 2019
license.txt chore: add license.txt. Nov 21, 2018
logo.png doc: use the correct logo. Jul 31, 2019
pom.xml [maven-release-plugin] prepare for next development iteration Aug 18, 2019
readme.md doc: Add a section describing quarkus integration. Jul 31, 2019
release.sh chore: release.sh now passes through arguemnts Dec 18, 2018

readme.md

dekorate logo

Dekorate

CircleCI Maven Central

Dekorate is a collection of Java compile-time generators and decorators for Kubernetes/OpenShift manifests.

It makes generating Kubernetes manifests as easy as adding a dependency to the classpath and customizing as simple as setting an annotation or application property.

Stop wasting time editing xml, json and yml and customize the kubernetes manifests as you configure your java application.

Rebranding Notice

This project was originally called ap4k which stood for Annotation Processors for Kubernetes. As the project now supports decorating of kubernetes manifests without the use of annotations, the name ap4k no longer describes the project in the best possible way. So, the project has been renamed to dekorate.

The new project page will be: http://dekorate.io and the new repository will be: https://github.com/dekorateio/dekorate. This repository will stay open until all remaining pull requests are processed and then it will redirect to https://github.com/dekorateio/dekorate.

For new issues and pull requests please don't forget to use https://github.com/dekorateio/dekorate.

Features

Experimental features

Rationale

The are tons of tools out there for scaffolding / generating kubernetes manifests. Sooner or later these manifests will require customization. Handcrafting is not an appealing option. Using external tools, is often too generic. Using build tool extensions and adding configuration via xml, groovy etc is a step forward, but still not optimal.

Annotation processing has quite a few advantages over external tools or build tool extensions:

  • Configuration is validated by the compiler.
  • Leverages tools like the IDE for writing type safe config (checking, completion etc).
  • Works with all build tools.
  • Can "react" to annotations provided by the framework.

Usage

To start using this project you just need to add one of the provided annotations to your project.

Kubernetes annotations

@KubernetesApplication can be added to your project like:

import io.dekorate.kubernetes.annotaion.KubernetesApplication;

@KubernetesApplication
public class Main {

    public static void main(String[] args) {
      //Your application code goes here.
    }
}

When the project gets compiled, the annotation will trigger the generation of a Deployment in both json and yml that will end up under 'target/classes/META-INF/dekorate'.

The annotation comes with a lot of parameters, which can be used in order to customize the Deployment and/or trigger the generations of addition resources, like Service and Ingress.

Adding the kubernetes annotation processor to the classpath

This module can be added to the project using:

<dependency>
  <groupId>io.dekorate</groupId>
  <artifactId>kubernetes-annotations</artifactId>
  <version>${project.version}</version>
</dependency>

related examples

Name and Version

So where did the generated Deployment gets its name, docker image etc from?

Everything can be customized via annotation parameters and system properties. On top of that lightweight integration with build tools is provided in order to reduce duplication.

Lightweight build tool integration

Lightweight integration with build tools, refers to reading information from the build tool config without bringing in the build tool itself into the classpath. The information read from the build tool is limited to:

  • name / artifactId
  • version
  • output file

For example in the case of maven it refers to parsing the pom.xml with DOM in order to fetch the artifactId and version.

Supported build tools:

  • maven
  • gradle
  • sbt
  • bazel

For all other build tools, the name and version need to be provided via the core annotations:

@KubernetesApplication(name = "my-app", version="1.1.0.Final")
public class Main {
}

or

@OpenshiftApplication(name = "my-app", version="1.1.0.Final")
public class Main {
}

and so on...

The information read from the build tool, is added to all resources as labels (name, version). They are also used to name images, containers, deployments, services etc.

For example for a gradle app, with the following gradle.properties:

name = my-gradle-app
version = 1.0.0

The following deployment will be generated:

apiVersion: "apps/v1"
kind: "Deployment"
metadata:
  name: "kubernetes-example"
spec:
  replicas: 1
  selector:
    matchLabels:
      app: "my-gradle-app"
      version: "1.0-SNAPSHOT"
      group: "default"
  template:
    metadata:
      labels:
        app: "my-gradle-app"
        version: "1.0-SNAPSHOT"
        group: "default"
    spec:
      containers:
      - env:
        - name: "KUBERNETES_NAMESPACE"
          valueFrom:
            fieldRef:
              fieldPath: "metadata.namespace"
        image: "default/my-gradle-app:1.0-SNAPSHOT"
        imagePullPolicy: "IfNotPresent"
        name: "my-gradle-app"

The output file name may be used in certain cases, to set the value of JAVA_APP_JAR an environment variable that points to the build jar.

Adding extra ports and exposing them as services

To add extra ports to the container, you can add one or more @Port into your @KubernetesApplication :

import io.dekorate.kubernetes.annotation.Env;
import io.dekorate.kubernetes.annotation.KubernetesApplication;

@KubernetesApplication(ports = @Port(name = "web", containerPort = 8080))
public class Main {

  public static void main(String[] args) {
    //Your code goes here
  }
}

This will trigger the addition of a container port to the Deployment but also will trigger the generation of a Service resource.

Note: This doesn't need to be done explicitly, if the application framework is detected and support, ports can be extracted from there (see below).

Adding container environment variables

To add extra environment variables to the container, you can add one or more @EnvVar into your @KubernetesApplication :

import io.dekorate.kubernetes.annotation.Env;
import io.dekorate.kubernetes.annotation.KubernetesApplication;

@KubernetesApplication(envVars = @Env(name = "key1", value = "var1"))
public class Main {

  public static void main(String[] args) {
    //Your code goes here
  }
}

Additional options are provided for adding environment variables from fields, config maps and secrets.

Working with volumes and mounts

To define volumes and mounts for your application, you can use something like:

import io.dekorate.kubernetes.annotation.Port;
import io.dekorate.kubernetes.annotation.Mount;
import io.dekorate.kubernetes.annotation.PersistentVolumeClaimVolume;
import io.dekorate.kubernetes.annotation.KubernetesApplication;

@KubernetesApplication(ports = @Port(name = "http", containerPort = 8080), 
  pvcVolumes = @PersistentVolumeClaimVolume(volumeName = "mysql-volume", claimName = "mysql-pvc"),
  mounts = @Mount(name = "mysql-volume", path = "/var/lib/mysql")
)
public class Main {

  public static void main(String[] args) {
    //Your code goes here
  }
}

Currently the supported annotations for specifying volumes are:

  • @PersistentVolumeClaimVolume
  • @SecretVolume
  • @ConfigMapVolume
  • @AwsElasticBlockStoreVolume
  • @AzureDiskVolume
  • @AzureFileVolume

Jvm Options

It's common to pass the JVM options in the manifests using the JAVA_OPTS environment variable of the application container. This is something complex as it usually difficult to remember all options by heart and thus its error prone. The worst part is that you don't realize the mistake until its TOO late.

Dekorate provides a way to manage those options using the @JvmOption annotation, which is included in the options-annotations.

import io.dekorate.options.annotation.JvmOptions
import io.dekorate.options.annotation.GarbageCollector;
import io.dekorate.kubernetes.annotation.KubernetesApplication;

@KubernetesApplication
@JvmOptions(server=true, xmx=1024, preferIpv4Stack=true, gc=GarbageCollector.SerialGC)
public class Main {

  public static void main(String[] args) {
    //Your code goes here
  }
}

This module can be added to the project using:

<dependency>
  <groupId>io.dekorate</groupId>
  <artifactId>option-annotations</artifactId>
  <version>${project.version}</version>
</dependency>

Note: The module is included in all starters.

Init Containers

If for any reason the application requires the use of init containers, they can be easily defined using the initContainer property, as demonstrated below.

import io.dekorate.kubernetes.annotation.Container;
import io.dekorate.kubernetes.annotation.KubernetesApplication;

@KubernetesApplication(initContainers = @Container(image="foo/bar:latest", command="foo"))
public class Main {

  public static void main(String[] args) {
    //Your code goes here
  }
}

The @Container supports the following fields:

  • Image
  • Image Pull Policy
  • Commands
  • Arguments
  • Environment Variables
  • Mounts
  • Probes

Sidecars

Similarly to init containers support for sidecars is also provided using the sidecars property. For example:

import io.dekorate.kubernetes.annotation.Container;
import io.dekorate.kubernetes.annotation.KubernetesApplication;

@KubernetesApplication(sidecars = @Container(image="jaegertracing/jaeger-agent",
                                             args="--collector.host-port=jaeger-collector.jaeger-infra.svc:14267"))
public class Main {

  public static void main(String[] args) {
    //Your code goes here
  }
}

As in the case of init containers the @Container supports the following fields:

  • Image
  • Image Pull Policy
  • Commands
  • Arguments
  • Environment Variables
  • Mounts
  • Probes

Adding the kubernetes annotation processor to the classpath

This module can be added to the project using:

<dependency>
  <groupId>io.dekorate</groupId>
  <artifactId>kubernetes-annotations</artifactId>
  <version>${project.version}</version>
</dependency>

OpenShift annotations

This module provides two new annotations:

  • @OpenshiftApplication

@OpenshiftApplication works exactly like @KubernetesApplication , but will generate resources in a file name openshift.yml / openshift.json instead. Also instead of creating a Deployment it will create a DeploymentConfig.

NOTE: A project can use both @KubernetesApplication and @OpenshiftApplication. If both the kubernetes and openshift annotation processors are present both kubernetes and openshift resources will be generated.

Adding the OpenShift annotation processor to the classpath

This module can be added to the project using:

<dependency>
  <groupId>io.dekorate</groupId>
  <artifactId>openshift-annotations</artifactId>
  <version>${project.version}</version>
</dependency>

Integrating with S2i

Out of the box resources for s2i will be generated.

  • ImageStream
    • builder
    • target
  • BuildConfig

Here's an example:

import io.dekorate.openshift.annotation.OpenshiftApplication;

@OpenshiftApplication(name = "doc-example")
public class Main {

    public static void main(String[] args) {
      //Your code goes here
    }
}

The generated BuildConfig will be a binary config. The actual build can be triggered from the command line with something like:

oc start-build doc-example --from-dir=./target --follow

NOTE: In the example above we explicitly set a name for our application, and we refernced that name from the cli. If the name was implicitly created the user would have to figure the name out before triggering the build. This could be done either by oc get bc or by knowing the conventions used to read names from build tool config (e.g. if maven then name the artifactId).

related examples

Prometheus annotations

The prometheus annotation processor provides annotations for generating prometheus related resources. In particular it can generate ServiceMonitor which are used by the Prometheus Operator in order to configure prometheus to collect metrics from the target application.

This is done with the use of @EnableServiceMonitor annotation.

Here's an example:

import io.dekorate.kubernetes.annotation.KubernentesApplication;
import io.dekorate.prometheus.annotation.EnableServiceMonitor;

@KubernetesApplication
@EnableServiceMonitor(port = "http", path="/prometheus", interval=20)
public class Main {
    public static void main(String[] args) {
      //Your code goes here
    }
}

The annotation processor, will automatically configure the required selector and generate the ServiceMonitor. Note: Some of the framework integration modules, may further decorate the ServiceMonitor with framework specific configuration. For example, the Spring Boot module will decorate the monitor with the Spring Boot specific path, which is /actuator/prometheus.

related examples

Jaeger annotations

The jaeger annotation processor provides annotations for injecting the jaeger-agent into the application pod.

Most of the work is done with the use of the @EnableJaegerAgent annotation.

Using the Jaeger Operator

When the jaeger operator is available, you set the operatorEnabled property to true. The annotation processor will automicatlly set the required annotations to the generated deployment, so that the jaeger operator can inject the jaeger-agent.

Here's an example:

import io.dekorate.kubernetes.annotation.KubernentesApplication;
import io.dekorate.jaeger.annotation.EnableJaegerAgent;

@KubernetesApplication
@EnableJaegerAgent(operatorEnabled="true")
public class Main {
    public static void main(String[] args) {
      //Your code goes here
    }
}
Manually injection the agent sidecar

For the cases, where the operator is not present, you can use the @EnableJaegerAgent to manually configure the sidecar.

import io.dekorate.kubernetes.annotation.KubernentesApplication;
import io.dekorate.jaeger.annotation.EnableJaegerAgent;

@KubernetesApplication
@EnableJaegerAgent
public class Main {
    public static void main(String[] args) {
      //Your code goes here
    }
}

related examples

Service Catalog annotations

The service catalog annotation processor is can be used in order to create service catalog resources for:

  • creating service instances
  • binding to services
  • injecting binding info into the container

Here's an example:

import io.dekorate.kubernetes.annotation.KubernetesApplication;
import io.dekorate.servicecatalog.annotation.ServiceCatalogInstance;
import io.dekorate.servicecatalog.annotation.ServiceCatalog;

@KubernetesApplication
@ServiceCatalog(instances =
    @ServiceCatalogInstance(name = "mysql-instance", serviceClass = "apb-mysql", servicePlan = "default")
)
public class Main {
    public static void main(String[] args) {
      //Your code goes here
    }
}

The @ServiceCatalogInstance annotation will trigger the generation of a ServiceInstance and a ServiceBindingresource. It will also decorate any Pod, Deployment, DeploymentConfig and so on with additional environment variables containing the binding information.

Adding the service catalog annotation processor to the classpath

This module can be added to the project using:

<dependency>
  <groupId>io.dekorate</groupId>
  <artifactId>servicecatalog-annotations</artifactId>
  <version>${project.version}</version>
</dependency>

related examples

Component CRD support

The Component Custom Resource Definition (CRD) aims to abstract kubernetes/OpenShift resources and simplify the configuration and design of cloud-native applications. See the following project to get more information about the Component CRD and its associated operator, more specifically you can take a look at the demo project. This module provides support for the Component CRD.

The generation of a Component CRD descriptor is triggered by adding the component-annotations dependency to the project and annotate one of your classes with @ComponentApplication. Note that in the case of Spring Boot applications, as explained here, only adding the dependency is needed:

<dependency>
  <groupId>io.dekorate</groupId>
  <artifactId>component-annotations</artifactId>
  <version>${project.version}</version>
</dependency>

If everything went well, building your project will also generate component.yml and component.json files in the target/classes/META-INF/dekorate is triggered.

The content of the component descriptor will be determined by the existing config provided by other annotations such as @KubernetesApplication and can be also controlled using application properties.

Framework integration

Framework integration modules are provided that we are able to detect framework annotations and adapt to the framework (e.g. expose ports).

The frameworks supported so far:

  • Spring Boot
  • Quarkus

Spring Boot

With spring boot its suggested to start with one of the provided starters:

<dependency>
  <groupId>io.dekorate</groupId>
  <artifactId>kubernetes-spring-starter</artifactId>
  <version>${project.version}</version>
</dependency>

Or if you are on openshift:

<dependency>
  <groupId>io.dekorate</groupId>
  <artifactId>openshfit-spring-starter</artifactId>
  <version>${project.version}</version>
</dependency>
Annotation less

For Spring Boot applications (i.e. at least one project class is annotated with @SpringBootApplication) all you need to do, is adding one of the starters (io.dekorate:kubernetes-spring-starter or io.dekorate:openshift-spring-starter) to the classpath. No need to specify an additional annotation. This provides the fastest way to get started using dekorate with spring boot.

To customize/dekorate the generated manifests you can use application.yml / application.properties both, or even use annotations along with application.yml / application.properties.

The order where these resources are used are:

  1. Annotations
  2. application.properties
  3. application.yaml
  4. application.yml
  5. application-kubernetes.properties
  6. application-kubernetes.yaml
  7. application-kubernetes.yml

Here's the full list of supported configuration options.

Generated resources when not using annotations

When no annotations are used, the kind of resources to be generated is determined by the dekorate artifacts found in the classpath.

File Required Dependency
kubernetes.json/yml io.dekorate:kubernetes-annotations
openshift.json/yml io.dekorate:openshift-annotations
component.json/yml io.dekorate:component-annotations

Note: that starter modules for kubernetes and openshift do transitively add kubernetes-annotations and openshift-annotations respectively.

Quarkus

quarkus provides rich set of extensions including one for kubernetes. The kubernetes extension uses internally dekorate for generating and customizing manifests.

The extension can be added to any quarkus project:

mvn quarkus:add-extension -Dextensions="io.quarkus:quarkus-kubernetes"

After the project compilation the generated manifests will be available under: target/wiring-classes/META-INF/kubernetes/.

At the moment this extension will handle ports, health checks etc, with zero configuration from the user side.

It's important to note, that by design this extension will NOT use the dekorate annotations for customizing the generated manifests.

For more information plese check: the extension docs.

Experimental features

Apart from the core feature, which is resource generation, there are a couple of experimental features that do add to the developer experience.

These features have to do with things like building, deploying and testing.

Building and Deploying?

Dekorate does not generate Dockerfiles, neither it provides internal support for performing docker or s2i builds. It does however allow the user to hook external tools (e.g. the docker or oc) to trigger container image builds after the end of compilation.

So, at the moment as an experimental feature the following hooks are provided:

  • docker build hook (requires docker binary, triggered with -Ddekorate.build=true)
  • docker push hook (requires docker binary, triggered with -Ddekorate.push=true)
  • openshift s2i build hook (requires oc binary, triggered with -Ddekorate.deploy=true)

Docker build hook

This hook will just trigger a docker build, using an existing Dockerfile at the root of the project. It will not generate or customize the docker build in anyway.

To enable the docker build hook you need:

  • a Dockerfile in the project/module root
  • the docker binary configured to point the docker daemon of your kubernetes environment.

To trigger the hook, you need to pass -Ddekorate.build=true as an argument to the build, for example:

mvn clean install -Ddekorate.build=true

or if you are using gradle:

gradle build -Ddekorate.build=true   

When push is enabled, the registry can be specified as part of the annotation, or via system properties. Here's an example via annotation configuration:

@EnableDockerBuild(registry="quay.io")
public class Main {
}

And here's how it can be done via build properties (system properties):

mvn clean install -Ddekorate.docker.registry=quay.io -Ddekorate.push=true    

Note: Dekorate will NOT push images on its own. It will delegate to the docker binary. So the user needs to make sure beforehand that is logged in and has taken all necessary actions for a docker push to work.

S2i build hook

This hook will just trigger an s2i binary build, that will pass the output folder as an input to the build

To enable the docker build hook you need:

  • the openshift-annotations module (already included in all openshift starter modules)
  • the oc binary configured to point the docker daemon of your kubernetes environment.

Finally, to trigger the hook, you need to pass -Ddekorate.build=true as an argument to the build, for example:

mvn clean install -Ddekorate.build=true

or if you are using gradle:

gradle build -Ddekorate.build=true  

Junit5 extensions

Dekorate provides two junit5 extensions for:

  • Kubernetes
  • Openshift

These extensions are dekorate aware and can read generated resources and configuration, in order to manage end to end tests for the annotated applications.

Features

  • Environment conditions
  • Container builds
  • Apply generated manifests to test environment
  • Inject test with:
    • client
    • application pod

Kubernetes extension for Junit5

The kubernetes extension can be used by adding the following dependency:

<dependency>
  <groupId>io.dekorate</groupId>
  <artifactId>kubernetes-junit</artifactId>
  <version>${project.version}</version>
</dependency>

This dependency gives access to @KubernetesIntegrationTest which is what enables the extension for your tests.

By adding the annotation to your test class the following things will happen:

  1. The extension will check if a kubernetes cluster is available (if not tests will be skipped).
  2. If @EnableDockerBuild is present in the project, a docker build will be triggered.
  3. All generated manifests will be applied.
  4. Will wait until applied resources are ready.
  5. Dependencies will be injected (e.g. KubernetesClient, Pod etc)
  6. Test will run
  7. Applied resources will be removed.
Dependency injection

Supported items for injection:

  • KubernetesClient
  • Pod (the application pod)
  • KubernetesList (the list with all generated resources)

To inject one of this you need a field in the code annotated with @Inject.

For example:

@Inject
KubernetesClient client;

When injecting a Pod, its likely that we need to specify the pod name. Since the pod name is not known in advance, we can use the deployment name instead. If the deployment is named hello-world then you can do something like:

@Inject
@Named("hello-world")
Pod pod;

Note: It is highly recommended to also add maven-failsafe-plugin configuration so that integration tests only run in the integration-test phase. This is important since in the test phase the application is not packaged. Here's an example of how it you can configure the project:

<plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-failsafe-plugin</artifactId>
  <version>${version.maven-failsafe-plugin}</version>
  <executions>
    <execution>
      <goals>
        <goal>integration-test</goal>
        <goal>verify</goal>
      </goals>
      <phase>integration-test</phase>
      <configuration>
        <includes>
          <include>**/*IT.class</include>
        </includes>
      </configuration>
    </execution>
  </executions>
</plugin>

related examples

OpenShift extension for JUnit5

Similarly to using the kubernetes junit extension you can use the extension for OpenShift, by adding @OpenshiftIntegrationTest. To use that you need to add:

<dependency>
  <groupId>io.dekorate</groupId>
  <artifactId>openshift-junit</artifactId>
  <version>${project.version}</version>
</dependency>

By adding the annotation to your test class the following things will happen:

  1. The extension will check if a kubernetes cluster is available (if not tests will be skipped).
  2. A docker build will be triggered.
  3. All generated manifests will be applied.
  4. Will wait until applied resources are ready.
  5. Dependencies will be injected (e.g. KubernetesClient, Pod etc)
  6. Test will run
  7. Applied resources will be removed.

related examples

Configuration externalization for known frameworks

It is often desired to externalize configuration in configuration files, instead of hard coding things inside annotations.

Dekorate is graudally adding support for configuration externalization for the supported frameworks:

  • spring boot

For these frameworks, the use of annotations is optional, as everything may be configured via configuration files. Each annotation may be expressed using properties or yaml using the following steps.

  • Each annotation property is expressed using a key/value pair.
  • All keys start with the dekorate.<annotation kind>. prefix, where annotation kind is the annotation class name in lowercase, stripped of the Application suffix.
  • The remaining part of key is the annotation property name.
  • For nesting properties the key is also nested following the previous rule.

Examples:

The following annotation configuration:

@KubernetesApplication(labels=@Label(key="foo", value="bar"))
public class Main {
}

Can be expressed using properties:

dekorate.kubernetes.labels[0].key=foo
dekorate.kubernetes.labels[0].value=bar

or using yaml:

dekorate:
  kubernetes:
    labels:
      - key: foo
        value: bar

In the examples above, dekorate is the prefix that we use to namespace the dekorate configuration. kubernetes defines the annotation kind (its @KubernetesApplication in lower case and stripped of the Application suffix). labels, key and value are the property names and since the Label is nested under @KubernetesApplication so are the properties.

The exact same example for openshift (where @OpenshiftApplication is used instead) would be:

@OpenshiftApplication(labels=@Label(key="foo", value="bar")) public class Main { }

Can be expressed using properties:

dekorate.openshift.labels[0].key=foo
dekorate.openshift.labels[0].value=bar

or using yaml:

dekorate:
  openshift:
    labels:
      - key: foo
        value: bar
Spring Boot

For spring boot, dekorate will look for configuration under:

  • application.properties
  • application.yml
  • application.yaml

Also it will look for the same files under the kubernetes profile:

  • application-kubernetes.properties
  • application-kubernetes.yml
  • application-kubernetes.yaml

External generator integration

No matter how good a generator/scaffolding tool is, its often desirable to handcraft part of it. Other times it might be desirable to combine different tools together (e.g. to generate the manifests using fmp but customize them via dekorate annotations)

No matter what the reason is, dekorate supports working on existing resources and decorating them based on the provided annotation configuration. This is as simple as letting dekorate know where to read the existing manifests and where to store the generated ones. By adding the @GeneratorOptions.

Integration with Fabric8 Maven Plugin.

The fabric8-maven-plugin can be used to package applications for kubernetes and openshift. It also supports generating manifests. A user might choose to build images using fmp, but customize them using dekorate annotations instead of xml.

An example could be to expose an additional port:

This can by done by configuring dekorate to read the fmp generated manifests from META-INF/fabric8 which is where fmp stores them and save them back there once decoration is done.

@GeneratorOptions(inputPath = "META-INF/fabric8", outputPath = "META-INF/fabric8")
@KubernetesApplication(port = @Port(name="srv", containerPort=8181)
public class Main {
   ... 
}

related examples

Want to get involved?

By all means please do! We love contributions! Docs, Bug fixes, New features ... everything is important!

Make sure you take a look at contributor guidelines. Also, it can be useful to have a look at the dekorate design.

You can’t perform that action at this time.