Rest client async header propagation with usage of Helidon Context (#…

…2735)

Rest client header propagation with usage of Helidon Context

Signed-off-by: David Kral <david.k.kral@oracle.com>

microprofile/rest-client/src/main/java/io/helidon/microprofile/restclient/HelidonInboundHeaderProvider.java

@@ -0,0 +1,38 @@
+/*
+ * Copyright (c) 2021 Oracle and/or its affiliates.
+ *
+ * Licensed 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 io.helidon.microprofile.restclient;
+
+import java.util.List;
+import java.util.Map;
+
+import io.helidon.common.context.Contexts;
+
+import org.glassfish.jersey.microprofile.restclient.InboundHeadersProvider;
+
+/**
+ * Provider which propagates inbound request headers via Helidon {@link io.helidon.common.context.Context}.
+ */
+class HelidonInboundHeaderProvider implements InboundHeadersProvider {
+
+    @Override
+    public Map<String, List<String>> inboundHeaders() {
+        return Contexts.context()
+                .flatMap(context -> context.get(InboundHeaders.class))
+                .map(InboundHeaders::getInboundHeaders)
+                .orElse(Map.of());
+    }
+
+}

microprofile/rest-client/src/main/java/io/helidon/microprofile/restclient/HelidonRequestHeaderAutoDiscoverable.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2021 Oracle and/or its affiliates.
+ *
+ * Licensed 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 io.helidon.microprofile.restclient;
+
+import javax.ws.rs.ConstrainedTo;
+import javax.ws.rs.RuntimeType;
+import javax.ws.rs.core.FeatureContext;
+
+import org.glassfish.jersey.internal.spi.ForcedAutoDiscoverable;
+
+/**
+ * Automatically discovered JAX-RS provider which registers Rest Client specific components to the server.
+ */
+@ConstrainedTo(RuntimeType.SERVER)
+public class HelidonRequestHeaderAutoDiscoverable implements ForcedAutoDiscoverable {
+    @Override
+    public void configure(FeatureContext context) {
+        if (!context.getConfiguration().isRegistered(HelidonRequestHeaderFilter.class)) {
+            context.register(HelidonRequestHeaderFilter.class);
+        }
+    }
+}

microprofile/rest-client/src/main/java/io/helidon/microprofile/restclient/HelidonRequestHeaderFilter.java

@@ -0,0 +1,37 @@
+/*
+ * Copyright (c) 2021 Oracle and/or its affiliates.
+ *
+ * Licensed 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 io.helidon.microprofile.restclient;
+
+import javax.ws.rs.ConstrainedTo;
+import javax.ws.rs.RuntimeType;
+import javax.ws.rs.container.ContainerRequestContext;
+import javax.ws.rs.container.ContainerRequestFilter;
+
+import io.helidon.common.context.Contexts;
+
+/**
+ * Server side request filter used for propagation of request headers to server client request.
+ * Uses {@link Contexts} to propagate headers.
+ */
+@ConstrainedTo(RuntimeType.SERVER)
+class HelidonRequestHeaderFilter implements ContainerRequestFilter {
+
+    @Override
+    public void filter(ContainerRequestContext requestContext) {
+        Contexts.context().ifPresent(context -> context.register(new InboundHeaders(requestContext.getHeaders())));
+    }
+
+}

microprofile/rest-client/src/main/java/io/helidon/microprofile/restclient/InboundHeaders.java

@@ -0,0 +1,35 @@
+/*
+ * Copyright (c) 2021 Oracle and/or its affiliates.
+ *
+ * Licensed 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 io.helidon.microprofile.restclient;
+
+import java.util.List;
+import java.util.Map;
+
+/**
+ * Wrapper object from obtained inbound request headers.
+ */
+class InboundHeaders {
+
+    private final Map<String, List<String>> inboundHeaders;
+
+    InboundHeaders(Map<String, List<String>> inboundHeaders) {
+        this.inboundHeaders = inboundHeaders;
+    }
+
+    public Map<String, List<String>> getInboundHeaders() {
+        return inboundHeaders;
+    }
+}

microprofile/rest-client/src/main/java/io/helidon/microprofile/restclient/MpRestClientListener.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019 Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2019, 2021 Oracle and/or its affiliates. All rights reserved.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -49,5 +49,7 @@ public void onNewClient(Class<?> aClass, RestClientBuilder restClientBuilder) {
         } catch (Exception e) {
             LOGGER.log(Level.FINE, "Failed to replace executor service for a REST Client: " + aClass, e);
         }
+
+        restClientBuilder.register(new HelidonInboundHeaderProvider());
     }
 }

microprofile/rest-client/src/main/java/module-info.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2019, 2020 Oracle and/or its affiliates.
+ * Copyright (c) 2019, 2021 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,9 +21,16 @@
     requires java.logging;
     requires transitive microprofile.rest.client.api;
     requires io.helidon.common.context;
+    requires jersey.common;
     requires jersey.mp.rest.client;
     requires java.ws.rs;
 
+    exports io.helidon.microprofile.restclient;
+    // needed for jersey injection
+    opens io.helidon.microprofile.restclient to hk2.locator,hk2.utils,weld.core.impl, io.helidon.microprofile.cdi;
+
     provides org.eclipse.microprofile.rest.client.spi.RestClientListener
             with io.helidon.microprofile.restclient.MpRestClientListener;
+    provides org.glassfish.jersey.internal.spi.ForcedAutoDiscoverable
+            with  io.helidon.microprofile.restclient.HelidonRequestHeaderAutoDiscoverable;
 }

microprofile/rest-client/src/main/resources/META-INF/services/org.glassfish.jersey.internal.spi.ForcedAutoDiscoverable

@@ -0,0 +1,17 @@
+#
+# Copyright (c) 2021 Oracle and/or its affiliates. All rights reserved.
+#
+# Licensed 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.
+#
+
+io.helidon.microprofile.restclient.HelidonRequestHeaderAutoDiscoverable