kamelets: load templates at build time

docs/modules/ROOT/pages/reference/extensions/kamelet.adoc

@@ -37,3 +37,46 @@ Or add the coordinates to your existing project:
 ----
 
 Check the xref:user-guide/index.adoc[User guide] for more information about writing Camel Quarkus applications.
+
+== Usage
+
+=== Pre-load Kamelets at build-time
+
+This extension allow to pre-load a set of Kamelets at build time through the following two options. The kamelet to pre-load can be listed using the `quarkus.camel.kamelet.names` property.
+
+=== Using the Kamelet Catalog
+
+//TODO: does not yet exist
+
+A set of pre-made Kamelets can be found on the https://camel.apache.org/camel-kamelets/latest[Kamelet Catalog].
+To use the Kamelet from the catalog you either need to copy them on your project in the classpath location defined by the `quarkus.camel.kamelet.location` property, or you can add the `camel-quarkus-kamelets-catalog` artifact to your `pom.xml`:
+
+[source,xml]
+----
+<dependency>
+    <groupId>org.apache.camel.quarkus</groupId>
+    <artifactId>camel-quarkus-kamelets-catalog</artifactId>
+</dependency>
+----
+
+This artifact makes all the kamelets available in the catalog available to Camel Quarkus for build time processing, the artefact is not part of the runtime classpath.
+
+
+== Additional Camel Quarkus configuration
+
+[width="100%",cols="80,5,15",options="header"]
+|===
+| Configuration property | Type | Default
+
+
+|icon:lock[title=Fixed at build time] [[quarkus.camel.kamelet.names]]`link:#quarkus.camel.kamelet.names[quarkus.camel.kamelet.names]`
+
+List of kamelets names to pre-load at build time. 
+ Each individual name is used to set the related `org.apache.camel.model.RouteTemplateDefinition` id. TODO: find a better name for this configuration option
+| `string`
+| 
+|===
+
+[.configuration-legend]
+icon:lock[title=Fixed at build time] Configuration property fixed at build time. All other configuration properties are overridable at runtime.
+

extensions/kamelet/deployment/pom.xml

@@ -38,6 +38,14 @@
             <groupId>org.apache.camel.quarkus</groupId>
             <artifactId>camel-quarkus-kamelet</artifactId>
         </dependency>
+        <dependency>
+            <groupId>com.fasterxml.jackson.dataformat</groupId>
+            <artifactId>jackson-dataformat-yaml</artifactId>
+        </dependency>
+        <dependency>
+            <groupId>org.apache.camel</groupId>
+            <artifactId>camel-yaml-dsl</artifactId>
+        </dependency>
     </dependencies>
 
     <build>

extensions/kamelet/deployment/src/main/java/org/apache/camel/quarkus/component/kamelet/deployment/KameletProcessor.java

@@ -16,15 +16,126 @@
  */
 package org.apache.camel.quarkus.component.kamelet.deployment;
 
+import java.io.InputStream;
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Optional;
+import java.util.stream.Collectors;
+
+import com.fasterxml.jackson.databind.DeserializationFeature;
+import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.databind.node.ObjectNode;
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
 import io.quarkus.deployment.annotations.BuildStep;
+import io.quarkus.deployment.annotations.ExecutionTime;
+import io.quarkus.deployment.annotations.Record;
 import io.quarkus.deployment.builditem.FeatureBuildItem;
+import org.apache.camel.Ordered;
+import org.apache.camel.builder.RouteBuilder;
+import org.apache.camel.dsl.yaml.YamlRoutesBuilderLoader;
+import org.apache.camel.impl.DefaultCamelContext;
+import org.apache.camel.model.RouteTemplateDefinition;
+import org.apache.camel.quarkus.component.kamelet.KameletConfiguration;
+import org.apache.camel.quarkus.component.kamelet.KameletRecorder;
+import org.apache.camel.quarkus.core.deployment.spi.CamelContextCustomizerBuildItem;
+import org.apache.camel.spi.Resource;
+import org.apache.camel.support.ResourceHelper;
 
 class KameletProcessor {
-
     private static final String FEATURE = "camel-kamelet";
 
     @BuildStep
     FeatureBuildItem feature() {
         return new FeatureBuildItem(FEATURE);
     }
+
+    @BuildStep
+    KameletResolverBuildItem defaultResolver(KameletConfiguration configuration) {
+        return new KameletResolverBuildItem(new KameletResolver() {
+            @Override
+            public Optional<InputStream> resolve(String id) throws Exception {
+                return Optional.ofNullable(
+                        Thread.currentThread().getContextClassLoader()
+                                .getResourceAsStream("/kamelets/" + id + ".kamelet.yaml"));
+            }
+        });
+    }
+
+    @Record(ExecutionTime.STATIC_INIT)
+    @BuildStep
+    CamelContextCustomizerBuildItem configureTemplates(
+            List<KameletResolverBuildItem> resolvers,
+            KameletConfiguration configuration,
+            KameletRecorder recorder) throws Exception {
+
+        ObjectMapper mapper = new ObjectMapper(new YAMLFactory())
+                .configure(DeserializationFeature.FAIL_ON_UNKNOWN_PROPERTIES, false);
+
+        List<RouteTemplateDefinition> definitions = new ArrayList<>();
+        List<KameletResolver> kameletResolvers = resolvers.stream()
+                .map(KameletResolverBuildItem::getResolver)
+                .sorted(Comparator.comparingInt(Ordered::getOrder))
+                .collect(Collectors.toList());
+
+        try (YamlRoutesBuilderLoader ybl = new YamlRoutesBuilderLoader()) {
+            ybl.setCamelContext(new DefaultCamelContext());
+            ybl.start();
+
+            for (String name : configuration.names.orElse(Collections.emptyList())) {
+
+                for (KameletResolver resolver : kameletResolvers) {
+                    final Optional<InputStream> is = resolver.resolve(name);
+                    if (!is.isPresent()) {
+                        continue;
+                    }
+
+                    try {
+                        final ObjectNode definition = (ObjectNode) mapper.readTree(is.get());
+                        final JsonNode properties = definition.requiredAt("/spec/definition/properties");
+                        final JsonNode flow = mapper.createArrayNode().add(definition.requiredAt("/spec/flow"));
+                        final Resource res = ResourceHelper.fromBytes(name + ".yaml", mapper.writeValueAsBytes(flow));
+
+                        RouteTemplateDefinition rt = new RouteTemplateDefinition();
+                        rt.setId(name);
+
+                        Iterator<Map.Entry<String, JsonNode>> it = properties.fields();
+                        while (it.hasNext()) {
+                            final Map.Entry<String, JsonNode> property = it.next();
+                            final String key = property.getKey();
+                            final JsonNode def = property.getValue().at("/default");
+
+                            if (def.isMissingNode()) {
+                                rt.templateParameter(key);
+                            } else {
+                                rt.templateParameter(key, def.asText());
+                            }
+                        }
+
+                        RouteBuilder rb = (RouteBuilder) ybl.loadRoutesBuilder(res);
+                        rb.configure();
+                        if (rb.getRouteCollection().getRoutes().size() != 1) {
+                            throw new IllegalStateException(
+                                    "A kamelet is not supposed to create more than one route ("
+                                            + "kamelet:" + name + ","
+                                            + "routes: " + rb.getRouteCollection().getRoutes().size()
+                                            + ")");
+                        }
+
+                        rt.setRoute(rb.getRouteCollection().getRoutes().get(0));
+
+                        definitions.add(rt);
+                    } finally {
+                        is.get().close();
+                    }
+                }
+            }
+        }
+
+        return new CamelContextCustomizerBuildItem(recorder.createTemplateLoaderCustomizer(definitions));
+    }
 }

extensions/kamelet/deployment/src/main/java/org/apache/camel/quarkus/component/kamelet/deployment/KameletResolver.java

@@ -0,0 +1,15 @@
+package org.apache.camel.quarkus.component.kamelet.deployment;
+
+import java.io.InputStream;
+import java.util.Optional;
+
+import org.apache.camel.Ordered;
+
+public interface KameletResolver extends Ordered {
+    Optional<InputStream> resolve(String id) throws Exception;
+
+    @Override
+    default int getOrder() {
+        return Ordered.LOWEST;
+    }
+}

extensions/kamelet/deployment/src/main/java/org/apache/camel/quarkus/component/kamelet/deployment/KameletResolverBuildItem.java

@@ -0,0 +1,20 @@
+package org.apache.camel.quarkus.component.kamelet.deployment;
+
+import io.quarkus.builder.item.MultiBuildItem;
+
+/**
+ * Build item used by kamelet providers to plug their own way of resolving kamelets giving a name. This could be
+ * leveraged by a future camel-quarkus-kamelet-catalog extension to resolve kamelets as they may have a different naming
+ * structure or location int the classpath.
+ */
+public final class KameletResolverBuildItem extends MultiBuildItem {
+    private final KameletResolver resolver;
+
+    public KameletResolverBuildItem(KameletResolver resolver) {
+        this.resolver = resolver;
+    }
+
+    public KameletResolver getResolver() {
+        return this.resolver;
+    }
+}

extensions/kamelet/runtime/src/main/doc/usage.adoc

@@ -0,0 +1,20 @@
+=== Pre-load Kamelets at build-time
+
+This extension allow to pre-load a set of Kamelets at build time through the following two options. The kamelet to pre-load can be listed using the `quarkus.camel.kamelet.names` property.
+
+=== Using the Kamelet Catalog
+
+//TODO: does not yet exist
+
+A set of pre-made Kamelets can be found on the https://camel.apache.org/camel-kamelets/latest[Kamelet Catalog].
+To use the Kamelet from the catalog you either need to copy them on your project in the classpath location defined by the `quarkus.camel.kamelet.location` property, or you can add the `camel-quarkus-kamelets-catalog` artifact to your `pom.xml`:
+
+[source,xml]
+----
+<dependency>
+    <groupId>org.apache.camel.quarkus</groupId>
+    <artifactId>camel-quarkus-kamelets-catalog</artifactId>
+</dependency>
+----
+
+This artifact makes all the kamelets available in the catalog available to Camel Quarkus for build time processing, the artefact is not part of the runtime classpath.

extensions/kamelet/runtime/src/main/java/org/apache/camel/quarkus/component/kamelet/KameletConfiguration.java

@@ -0,0 +1,37 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.camel.quarkus.component.kamelet;
+
+import java.util.List;
+import java.util.Optional;
+
+import io.quarkus.runtime.annotations.ConfigItem;
+import io.quarkus.runtime.annotations.ConfigPhase;
+import io.quarkus.runtime.annotations.ConfigRoot;
+
+@ConfigRoot(name = "camel.kamelet", phase = ConfigPhase.BUILD_TIME)
+public class KameletConfiguration {
+    /**
+     * List of kamelets names to pre-load at build time.
+     *
+     * <p/>
+     * Each individual name is used to set the related {@link org.apache.camel.model.RouteTemplateDefinition} id.
+     * TODO: find a better name for this configuration option
+     */
+    @ConfigItem
+    public Optional<List<String>> names;
+}

extensions/kamelet/runtime/src/main/java/org/apache/camel/quarkus/component/kamelet/KameletRecorder.java

@@ -0,0 +1,42 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.camel.quarkus.component.kamelet;
+
+import java.util.List;
+
+import io.quarkus.runtime.RuntimeValue;
+import io.quarkus.runtime.annotations.Recorder;
+import org.apache.camel.CamelContext;
+import org.apache.camel.model.Model;
+import org.apache.camel.model.RouteTemplateDefinition;
+import org.apache.camel.quarkus.core.CamelContextCustomizer;
+
+@Recorder
+public class KameletRecorder {
+    public RuntimeValue<CamelContextCustomizer> createTemplateLoaderCustomizer(List<RouteTemplateDefinition> definitions) {
+        return new RuntimeValue<>(new CamelContextCustomizer() {
+            @Override
+            public void customize(CamelContext context) {
+                try {
+                    context.getExtension(Model.class).addRouteTemplateDefinitions(definitions);
+                } catch (Exception e) {
+                    throw new RuntimeException(e);
+                }
+            }
+        });
+    }
+}

integration-tests/kamelet/pom.xml

@@ -59,6 +59,10 @@
             <groupId>io.quarkus</groupId>
             <artifactId>quarkus-resteasy</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.quarkus</groupId>
+            <artifactId>quarkus-resteasy-jsonb</artifactId>
+        </dependency>
 
         <!-- test dependencies -->
         <dependency>

integration-tests/kamelet/src/main/java/org/apache/camel/quarkus/component/kamelet/it/KameletResource.java

@@ -17,19 +17,28 @@
 package org.apache.camel.quarkus.component.kamelet.it;
 
 import javax.inject.Inject;
+import javax.json.Json;
+import javax.json.JsonArray;
+import javax.json.JsonArrayBuilder;
 import javax.ws.rs.Consumes;
 import javax.ws.rs.GET;
 import javax.ws.rs.POST;
 import javax.ws.rs.Path;
 import javax.ws.rs.Produces;
 import javax.ws.rs.core.MediaType;
 
+import org.apache.camel.CamelContext;
 import org.apache.camel.ConsumerTemplate;
 import org.apache.camel.FluentProducerTemplate;
+import org.apache.camel.model.Model;
+import org.apache.camel.model.OptionalIdentifiedDefinition;
 
 @Path("/kamelet")
 public class KameletResource {
 
+    @Inject
+    CamelContext camelContext;
+
     @Inject
     FluentProducerTemplate fluentProducerTemplate;
 
@@ -64,4 +73,19 @@ public String bodyFromProperty() throws Exception {
     public String kameletChain(String message) throws Exception {
         return fluentProducerTemplate.to("direct:chain").withBody(message).request(String.class);
     }
+
+    @Path("/list")
+    @GET
+    @Produces(MediaType.TEXT_PLAIN)
+    public JsonArray list() {
+        JsonArrayBuilder builder = Json.createArrayBuilder();
+
+        camelContext.getExtension(Model.class)
+                .getRouteTemplateDefinitions()
+                .stream()
+                .map(OptionalIdentifiedDefinition::getId)
+                .forEach(builder::add);
+
+        return builder.build();
+    }
 }

integration-tests/kamelet/src/main/resources/application.properties

@@ -15,3 +15,5 @@
 ## limitations under the License.
 ## ---------------------------------------------------------------------------
 camel.kamelet.setBodyFromProperties.bodyValueFromProperty=Camel Quarkus Kamelet Property
+
+quarkus.camel.kamelet.names = injector,logger