4.x: Oci integration fixes (#8927)

* Fix stack-overflow when getting region from SDK.

* Fixed missed configured option in OciConfig.
Using a custom webclient request to check if IMDS endpoint is valid (as the default that used Region discovery has hardcoded 7 retries and increasing delays between them).
Added config-yaml as a runtime dependency, as without it the OCI configuration does not work.

integrations/oci/oci/pom.xml

@@ -43,14 +43,18 @@
             <groupId>io.helidon.config</groupId>
             <artifactId>helidon-config</artifactId>
         </dependency>
+        <dependency>
+            <groupId>io.helidon.config</groupId>
+            <artifactId>helidon-config-yaml</artifactId>
+            <scope>runtime</scope>
+        </dependency>
         <dependency>
             <groupId>com.oracle.oci.sdk</groupId>
             <artifactId>oci-java-sdk-common</artifactId>
         </dependency>
         <dependency>
-            <groupId>io.helidon.config</groupId>
-            <artifactId>helidon-config-yaml</artifactId>
-            <scope>test</scope>
+            <groupId>io.helidon.webclient</groupId>
+            <artifactId>helidon-webclient</artifactId>
         </dependency>
         <dependency>
             <groupId>io.helidon.common.testing</groupId>

integrations/oci/oci/src/main/java/io/helidon/integrations/oci/HelidonOci.java

@@ -17,11 +17,18 @@
 package io.helidon.integrations.oci;
 
 import java.io.IOException;
+import java.lang.System.Logger.Level;
 import java.net.InetAddress;
 import java.net.URI;
 import java.time.Duration;
 
+import io.helidon.common.media.type.MediaTypes;
+import io.helidon.http.Status;
+import io.helidon.webclient.api.ClientResponseTyped;
+import io.helidon.webclient.api.WebClient;
+
 import static io.helidon.integrations.oci.OciConfigSupport.IMDS_HOSTNAME;
+import static io.helidon.integrations.oci.OciConfigSupport.IMDS_URI;
 
 /**
  * Helper methods for OCI integration.
@@ -42,17 +49,56 @@ public static boolean imdsAvailable(OciConfig config) {
         Duration timeout = config.imdsTimeout();
 
         try {
-            if (InetAddress.getByName(config.imdsBaseUri().map(URI::getHost).orElse(IMDS_HOSTNAME))
+            URI imdsUri = config.imdsBaseUri()
+                    .orElse(IMDS_URI);
+
+            if (InetAddress.getByName(imdsUri.getHost())
                     .isReachable((int) timeout.toMillis())) {
-                return RegionProviderSdk.regionFromImds(config) != null;
+                return imdsAvailable(config, imdsUri);
             }
             return false;
         } catch (IOException e) {
-            LOGGER.log(System.Logger.Level.TRACE,
+            LOGGER.log(Level.TRACE,
                        "IMDS service is not reachable, or timed out for address: "
                                + IMDS_HOSTNAME + ".",
                        e);
             return false;
         }
     }
+
+    private static boolean imdsAvailable(OciConfig config, URI imdsUri) {
+        // check if the endpoint is available (we have only checked the host/IP address)
+        int retries = config.imdsDetectRetries().orElse(0);
+
+        Exception firstException = null;
+        Status firstStatus = null;
+
+        for (int retry = 0; retry <= retries; retry++) {
+            try {
+                ClientResponseTyped<String> response = WebClient.builder()
+                        .connectTimeout(config.imdsTimeout())
+                        .readTimeout(config.imdsTimeout())
+                        .baseUri(imdsUri)
+                        .build()
+                        .get("instance/regionInfo")
+                        .accept(MediaTypes.APPLICATION_JSON)
+                        .request(String.class);
+                if (response.status() == Status.OK_200) {
+                    return true;
+                }
+                firstStatus = firstStatus == null ? response.status() : firstStatus;
+            } catch (Exception e) {
+                firstException = firstException == null ? e : firstException;
+            }
+        }
+        String message = "OCI IMDS not available on " + imdsUri;
+        if (firstException == null) {
+            LOGGER.log(Level.INFO, message + " Status received: " + firstStatus);
+        } else {
+            LOGGER.log(Level.INFO, message + " Exception logged only in TRACE");
+            LOGGER.log(Level.TRACE, message, firstException);
+        }
+
+        return false;
+    }
 }

integrations/oci/oci/src/main/java/io/helidon/integrations/oci/OciConfigBlueprint.java

@@ -141,6 +141,7 @@ interface OciConfigBlueprint {
      *
      * @return number of retries, each provider has its own defaults
      */
+    @Option.Configured
     Optional<Integer> imdsDetectRetries();
 
     /**

integrations/oci/oci/src/main/java/io/helidon/integrations/oci/OciConfigSupport.java

@@ -16,6 +16,8 @@
 
 package io.helidon.integrations.oci;
 
+import java.net.URI;
+
 import io.helidon.builder.api.Prototype;
 import io.helidon.common.config.Config;
 
@@ -28,6 +30,8 @@ final class OciConfigSupport {
     // we do not use the constant, as it is marked as internal, and we only need the IP address anyway
     // see com.oracle.bmc.auth.AbstractFederationClientAuthenticationDetailsProviderBuilder.METADATA_SERVICE_BASE_URL
     static final String IMDS_HOSTNAME = "169.254.169.254";
+    @SuppressWarnings("HttpUrlsUsage") // this is a known endpoint available only on OCI instances
+    static final URI IMDS_URI = URI.create("http://" + IMDS_HOSTNAME + "/opc/v2/");
 
     private OciConfigSupport() {
     }

integrations/oci/oci/src/main/java/io/helidon/integrations/oci/RegionProviderSdk.java

@@ -43,18 +43,24 @@ class RegionProviderSdk implements OciRegion {
      */
     static Region regionFromImds(OciConfig ociConfig) {
         if (HelidonOci.imdsAvailable(ociConfig)) {
-            Optional<URI> uri = ociConfig.imdsBaseUri();
-            return uri.map(URI::toString)
-                    .map(Region::getRegionFromImds)
-                    .orElseGet(() -> {
-                        Region.registerFromInstanceMetadataService();
-                        return Region.getRegionFromImds();
-                    });
-
+            return regionFromImdsDirect(ociConfig);
         }
         return null;
     }
 
+    /**
+     * Only called when we know imds is available.
+     */
+    static Region regionFromImdsDirect(OciConfig ociConfig) {
+        Optional<URI> uri = ociConfig.imdsBaseUri();
+        return uri.map(URI::toString)
+                .map(Region::getRegionFromImds)
+                .orElseGet(() -> {
+                    Region.registerFromInstanceMetadataService();
+                    return Region.getRegionFromImds();
+                });
+    }
+
     @Override
     public Optional<Region> region() {
         return region.get();

integrations/oci/oci/src/main/java/module-info.java

@@ -49,6 +49,7 @@
     requires io.helidon.service.registry;
     requires io.helidon.common.config;
     requires io.helidon.config;
+    requires io.helidon.webclient;
 
     requires oci.java.sdk.common;
     requires vavr;