Add support for CaaS

cf-java-logging-support-opentelemetry-agent-extension/src/main/java/com/sap/hcf/cf/logging/opentelemetry/agent/ext/CloudLoggingConfigurationCustomizerProvider.java

@@ -1,21 +1,32 @@
 package com.sap.hcf.cf.logging.opentelemetry.agent.ext;
 
+import com.sap.hcf.cf.logging.opentelemetry.agent.ext.binding.CaasBindingPropertiesSupplier;
 import com.sap.hcf.cf.logging.opentelemetry.agent.ext.binding.CloudLoggingBindingPropertiesSupplier;
+import com.sap.hcf.cf.logging.opentelemetry.agent.ext.binding.DefaultOtelBackendPropertiesSupplier;
 import com.sap.hcf.cf.logging.opentelemetry.agent.ext.exporter.SanitizeSpanExporterCustomizer;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizer;
 import io.opentelemetry.sdk.autoconfigure.spi.AutoConfigurationCustomizerProvider;
 
 import java.util.logging.Logger;
 
+import static com.sap.hcf.cf.logging.opentelemetry.agent.ext.binding.DefaultOtelBackendPropertiesSupplier.builder;
+
 public class CloudLoggingConfigurationCustomizerProvider implements AutoConfigurationCustomizerProvider {
 
     private static final Logger LOG = Logger.getLogger(CloudLoggingConfigurationCustomizerProvider.class.getName());
     private static final String VERSION = "4.0.0";
 
+    private static DefaultOtelBackendPropertiesSupplier getDefaultOtelBackendPropertiesSupplier() {
+        return builder() //
+                         .add(new CaasBindingPropertiesSupplier()) // this has priority
+                         .add(new CloudLoggingBindingPropertiesSupplier()) // look for Cloud Logging as fallback and backward compatibility
+                         .build();
+    }
+
     @Override
     public void customize(AutoConfigurationCustomizer autoConfiguration) {
         LOG.info("Initializing SAP BTP Observability extension " + VERSION);
-        autoConfiguration.addPropertiesSupplier(new CloudLoggingBindingPropertiesSupplier());
+        autoConfiguration.addPropertiesSupplier(getDefaultOtelBackendPropertiesSupplier());
         autoConfiguration.addSpanExporterCustomizer(new SanitizeSpanExporterCustomizer());
     }
 

cf-java-logging-support-opentelemetry-agent-extension/src/main/java/com/sap/hcf/cf/logging/opentelemetry/agent/ext/binding/CaasBindingPropertiesSupplier.java

@@ -0,0 +1,106 @@
+package com.sap.hcf.cf.logging.opentelemetry.agent.ext.binding;
+
+import com.sap.hcf.cf.logging.opentelemetry.agent.ext.tls.PemFileCreator;
+import com.sap.hcf.cf.logging.opentelemetry.agent.ext.tls.ServerCertificateDownloader;
+import io.opentelemetry.common.ComponentLoader;
+import io.opentelemetry.sdk.autoconfigure.spi.internal.DefaultConfigProperties;
+
+import java.io.File;
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.function.Supplier;
+import java.util.logging.Logger;
+
+import static java.util.Collections.emptyMap;
+
+public class CaasBindingPropertiesSupplier implements Supplier<Map<String, String>> {
+
+    private static final String CAAS_CLIENT_KEY = "tls.key";
+    private static final String CAAS_CLIENT_CERT = "tls.crt";
+    private static final String CAAS_ENDPOINT = "http-url";
+    private static final String CAAS_PORT_PLACEHOLDER = "<http-receiver-port>";
+    private static final String PORT_OTLP_HTTP = "4318";
+
+    private static final Logger LOG = Logger.getLogger(CaasBindingPropertiesSupplier.class.getName());
+
+    private final CaasServiceProvider serviceProvider;
+    private final PemFileCreator pemFileCreator;
+    private final ServerCertificateDownloader serverCertificateDownloader;
+
+    public CaasBindingPropertiesSupplier() {
+        this(new CaasServiceProvider(getDefaultConfigProperties()), new PemFileCreator(),
+             new ServerCertificateDownloader());
+    }
+
+    CaasBindingPropertiesSupplier(CaasServiceProvider serviceProvider, PemFileCreator pemFileCreator,
+                                  ServerCertificateDownloader serverCertificateDownloader) {
+        this.serviceProvider = serviceProvider;
+        this.pemFileCreator = pemFileCreator;
+        this.serverCertificateDownloader = serverCertificateDownloader;
+    }
+
+    private static DefaultConfigProperties getDefaultConfigProperties() {
+        ComponentLoader componentLoader =
+                ComponentLoader.forClassLoader(DefaultConfigProperties.class.getClassLoader());
+        return DefaultConfigProperties.create(emptyMap(), componentLoader);
+    }
+
+    private static void putCaasDefaultProperties(Map<String, String> properties) {
+        properties.put("otel.exporter.otlp.protocol", "http/protobuf");
+        properties.put("otel.exporter.otlp.compression", "gzip");
+    }
+
+    @Override
+    public Map<String, String> get() {
+        CloudFoundryServiceInstance serviceInstance = serviceProvider.get();
+        if (serviceInstance == null) {
+            LOG.config("No CaaS service instance found.");
+            return emptyMap();
+        }
+        CloudFoundryCredentials credentials = serviceInstance.getCredentials();
+        if (credentials == null) {
+            LOG.warning(() -> "CaaS service instance '" + serviceInstance.getName() + "' has no credentials.");
+            return emptyMap();
+        }
+        String endpointUrl = credentials.getString(CAAS_ENDPOINT);
+        if (endpointUrl == null || endpointUrl.isBlank()) {
+            LOG.warning(() -> "CaaS service instance '" + serviceInstance.getName() + "' has no endpoint URL.");
+            return emptyMap();
+        }
+
+        Map<String, String> properties = new HashMap<>();
+        endpointUrl = endpointUrl.replace(CAAS_PORT_PLACEHOLDER, PORT_OTLP_HTTP);
+        LOG.config("Using CaaS OTLP endpoint URL: " + endpointUrl);
+        properties.put("otel.exporter.otlp.endpoint", endpointUrl);
+
+        putCaasDefaultProperties(properties);
+
+        String clientCert = credentials.getString(CAAS_CLIENT_CERT);
+        String clientKey = credentials.getString(CAAS_CLIENT_KEY);
+        if (clientCert != null && clientKey != null) {
+            try {
+                String serverCert = serverCertificateDownloader.download(endpointUrl);
+                if (serverCert == null || serverCert.isBlank()) {
+                    return properties;
+                }
+                File serverCertFile = pemFileCreator.writeFile("caas-server-cert-", ".crt", serverCert);
+                File clientCertFile = pemFileCreator.writeFile("caas-client-cert-", ".crt", clientCert);
+                File clientKeyFile = pemFileCreator.writeFile("caas-client-key-", ".key", clientKey);
+
+                properties.put("otel.exporter.otlp.certificate", serverCertFile.getAbsolutePath());
+                properties.put("otel.exporter.otlp.client.certificate", clientCertFile.getAbsolutePath());
+                properties.put("otel.exporter.otlp.client.key", clientKeyFile.getAbsolutePath());
+
+            } catch (IOException e) {
+                LOG.warning(
+                        () -> "Failed to create PEM files for CaaS service instance '" + serviceInstance.getName() + "': " + e.getMessage());
+            }
+        } else {
+            LOG.warning(
+                    () -> "CaaS service instance '" + serviceInstance.getName() + "' is missing client certificate or key.");
+        }
+        return properties;
+    }
+
+}

cf-java-logging-support-opentelemetry-agent-extension/src/main/java/com/sap/hcf/cf/logging/opentelemetry/agent/ext/binding/CaasServiceProvider.java

@@ -0,0 +1,27 @@
+package com.sap.hcf.cf.logging.opentelemetry.agent.ext.binding;
+
+import com.sap.hcf.cf.logging.opentelemetry.agent.ext.config.ExtensionConfigurations;
+import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
+
+import java.util.Collections;
+import java.util.function.Supplier;
+
+public class CaasServiceProvider implements Supplier<CloudFoundryServiceInstance> {
+
+    private final CloudFoundryServiceInstance service;
+
+    public CaasServiceProvider(ConfigProperties config) {
+        this(config, new CloudFoundryServicesAdapter());
+    }
+
+    CaasServiceProvider(ConfigProperties config, CloudFoundryServicesAdapter adapter) {
+        String label = ExtensionConfigurations.RUNTIME.CLOUD_FOUNDRY.SERVICE.CAAS.LABEL.getValue(config);
+        this.service =
+                adapter.stream(Collections.singletonList(label), Collections.emptyList()).findFirst().orElse(null);
+    }
+
+    @Override
+    public CloudFoundryServiceInstance get() {
+        return service;
+    }
+}

cf-java-logging-support-opentelemetry-agent-extension/src/main/java/com/sap/hcf/cf/logging/opentelemetry/agent/ext/binding/CloudLoggingBindingPropertiesSupplier.java

@@ -1,12 +1,12 @@
 package com.sap.hcf.cf.logging.opentelemetry.agent.ext.binding;
 
 import com.sap.hcf.cf.logging.opentelemetry.agent.ext.config.ExtensionConfigurations.DEPRECATED;
+import com.sap.hcf.cf.logging.opentelemetry.agent.ext.tls.PemFileCreator;
 import io.opentelemetry.common.ComponentLoader;
 import io.opentelemetry.sdk.autoconfigure.spi.ConfigProperties;
 import io.opentelemetry.sdk.autoconfigure.spi.internal.DefaultConfigProperties;
 
 import java.io.File;
-import java.io.FileWriter;
 import java.io.IOException;
 import java.util.Collections;
 import java.util.HashMap;
@@ -24,13 +24,17 @@ public class CloudLoggingBindingPropertiesSupplier implements Supplier<Map<Strin
     private static final String OTLP_SERVER_CERT = "server-ca";
 
     private final CloudLoggingServicesProvider cloudLoggingServicesProvider;
+    private final PemFileCreator pemFileCreator;
 
     public CloudLoggingBindingPropertiesSupplier() {
-        this(new CloudLoggingServicesProvider(getDefaultProperties(), new CloudFoundryServicesAdapter()));
+        this(new CloudLoggingServicesProvider(getDefaultProperties(), new CloudFoundryServicesAdapter()),
+             new PemFileCreator());
     }
 
-    CloudLoggingBindingPropertiesSupplier(CloudLoggingServicesProvider cloudLoggingServicesProvider) {
+    CloudLoggingBindingPropertiesSupplier(CloudLoggingServicesProvider cloudLoggingServicesProvider,
+                                          PemFileCreator pemFileCreator) {
         this.cloudLoggingServicesProvider = cloudLoggingServicesProvider;
+        this.pemFileCreator = pemFileCreator;
     }
 
     private static ConfigProperties getDefaultProperties() {
@@ -47,16 +51,6 @@ private static boolean isBlank(String text) {
         return text == null || text.trim().isEmpty();
     }
 
-    private static File writeFile(String prefix, String suffix, String content) throws IOException {
-        File file = File.createTempFile(prefix, suffix);
-        file.deleteOnExit();
-        try (FileWriter writer = new FileWriter(file)) {
-            writer.append(content);
-            LOG.fine("Created temporary file " + file.getAbsolutePath());
-        }
-        return file;
-    }
-
     /**
      * Scans service bindings, both managed and user-provided for Cloud Logging. Managed services require the label
      * "cloud-logging" to be considered. Services will be selected by the tag "Cloud Logging". User-provided services
@@ -95,9 +89,9 @@ private Map<String, String> createEndpointConfiguration(CloudFoundryServiceInsta
         }
 
         try {
-            File clientKeyFile = writeFile("cloud-logging-client", ".key", clientKey);
-            File clientCertFile = writeFile("cloud-logging-client", ".cert", clientCert);
-            File serverCertFile = writeFile("cloud-logging-server", ".cert", serverCert);
+            File clientKeyFile = pemFileCreator.writeFile("cloud-logging-client", ".key", clientKey);
+            File clientCertFile = pemFileCreator.writeFile("cloud-logging-client", ".cert", clientCert);
+            File serverCertFile = pemFileCreator.writeFile("cloud-logging-server", ".cert", serverCert);
 
             HashMap<String, String> properties = new HashMap<>();
             properties.put("otel.exporter.otlp.endpoint", "https://" + endpoint);

cf-java-logging-support-opentelemetry-agent-extension/src/main/java/com/sap/hcf/cf/logging/opentelemetry/agent/ext/binding/DefaultOtelBackendPropertiesSupplier.java

@@ -0,0 +1,48 @@
+package com.sap.hcf.cf.logging.opentelemetry.agent.ext.binding;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.function.Supplier;
+import java.util.logging.Logger;
+
+import static java.util.Collections.emptyMap;
+import static java.util.function.Predicate.not;
+
+public class DefaultOtelBackendPropertiesSupplier implements Supplier<Map<String, String>> {
+
+    private static final Logger LOG = Logger.getLogger(DefaultOtelBackendPropertiesSupplier.class.getName());
+
+    private final List<Supplier<Map<String, String>>> suppliers;
+
+    private DefaultOtelBackendPropertiesSupplier(Builder builder) {
+        this.suppliers = builder.suppliers;
+    }
+
+    @Override
+    public Map<String, String> get() {
+        if (suppliers.isEmpty()) {
+            LOG.config("No OpenTelemetry backend properties suppliers configured.");
+            return emptyMap();
+        }
+        return suppliers.stream().map(Supplier::get).filter(not(Map::isEmpty)).findFirst().orElse(emptyMap());
+    }
+
+    public static Builder builder() {
+        return new Builder();
+    }
+
+    public static class Builder {
+
+        private final List<Supplier<Map<String, String>>> suppliers = new ArrayList<>();
+
+        public Builder add(Supplier<Map<String, String>> supplier) {
+            suppliers.add(supplier);
+            return this;
+        }
+
+        public DefaultOtelBackendPropertiesSupplier build() {
+            return new DefaultOtelBackendPropertiesSupplier(this);
+        }
+    }
+}

cf-java-logging-support-opentelemetry-agent-extension/src/main/java/com/sap/hcf/cf/logging/opentelemetry/agent/ext/config/ExtensionConfigurations.java

@@ -213,6 +213,16 @@ interface CLOUD_FOUNDRY {
     interface RUNTIME {
         interface CLOUD_FOUNDRY {
             interface SERVICE {
+                interface CAAS {
+                    /**
+                     * <p>Parses {@code sap.caas.cf.binding.label.value}.</p>
+                     * <p>The label value used to identify managed CaaS service bindings. Default is
+                     * {@code "caas-service"}.</p>
+                     */
+                    ConfigProperty<String> LABEL =
+                            stringValued("sap.caas.cf.binding.label.value").withDefaultValue("caas-service").build();
+                }
+
                 interface CLOUD_LOGGING {
                     /**
                      * <p>Parses {@code sap.cloud-logging.cf.binding.label.value}.</p>

cf-java-logging-support-opentelemetry-agent-extension/src/main/java/com/sap/hcf/cf/logging/opentelemetry/agent/ext/tls/PemFileCreator.java

@@ -0,0 +1,21 @@
+package com.sap.hcf.cf.logging.opentelemetry.agent.ext.tls;
+
+import java.io.File;
+import java.io.FileWriter;
+import java.io.IOException;
+import java.util.logging.Logger;
+
+public class PemFileCreator {
+
+    private static final Logger LOG = Logger.getLogger(PemFileCreator.class.getName());
+
+    public File writeFile(String prefix, String suffix, String content) throws IOException {
+        File file = File.createTempFile(prefix, suffix);
+        file.deleteOnExit();
+        try (FileWriter writer = new FileWriter(file)) {
+            writer.append(content);
+            LOG.fine("Created temporary file " + file.getAbsolutePath());
+        }
+        return file;
+    }
+}