Add Storage Account Entra ID credentials cache (#271)

src/main/java/com/microsoft/azure/util/AzureCredentials.java

@@ -25,6 +25,7 @@
 import com.cloudbees.plugins.credentials.impl.BaseStandardCredentials;
 import com.cloudbees.plugins.credentials.impl.CertificateCredentialsImpl;
 import com.microsoft.jenkins.credentials.AzureResourceManagerCache;
+import com.microsoft.jenkins.credentials.BlobServiceClientCache;
 import com.microsoft.jenkins.keyvault.SecretClientCache;
 import edu.umd.cs.findbugs.annotations.NonNull;
 import edu.umd.cs.findbugs.annotations.Nullable;
@@ -453,6 +454,7 @@ public AzureCredentials(
         data = new ServicePrincipal(subscriptionId, clientId, clientSecret);
         SecretClientCache.invalidateCache();
         AzureResourceManagerCache.invalidateCache();
+        BlobServiceClientCache.invalidateCache();
     }
 
     /**

src/main/java/com/microsoft/jenkins/credentials/BlobServiceClientCache.java

@@ -0,0 +1,95 @@
+/*
+Copyright 2024 Tim Jacomb
+
+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 com.microsoft.jenkins.credentials;
+
+import com.azure.core.credential.TokenCredential;
+import com.azure.storage.blob.BlobServiceClient;
+import com.azure.storage.blob.BlobServiceClientBuilder;
+import com.github.benmanes.caffeine.cache.Caffeine;
+import com.github.benmanes.caffeine.cache.LoadingCache;
+import com.microsoft.azure.util.AzureBaseCredentials;
+import com.microsoft.azure.util.AzureCredentialUtil;
+import com.microsoft.azure.util.AzureCredentials;
+import edu.umd.cs.findbugs.annotations.CheckForNull;
+import io.jenkins.plugins.azuresdk.HttpClientRetriever;
+import java.time.Duration;
+import java.util.Objects;
+
+public final class BlobServiceClientCache {
+
+    private static final long MAX_SIZE = 50L;
+    private static final Duration EXPIRE_AFTER = Duration.ofHours(24);
+
+    private static final LoadingCache<BlobServiceClientCache.CacheKey, BlobServiceClient> CACHE = Caffeine.newBuilder()
+            .maximumSize(MAX_SIZE)
+            .expireAfterWrite(EXPIRE_AFTER)
+            .build(BlobServiceClientCache::createClient);
+
+    private BlobServiceClientCache() {}
+
+    @CheckForNull
+    public static BlobServiceClient get(String credentialsId, String blobServiceEndpoint) {
+        return CACHE.get(new CacheKey(credentialsId, blobServiceEndpoint));
+    }
+
+    /**
+     * Used to notify when credentials change, e.g. service principal secret updated.
+     */
+    public static void invalidateCache() {
+        // Could be optimised to only invalidate specific keys in the future if required
+        CACHE.invalidateAll();
+    }
+
+    private static BlobServiceClient createClient(CacheKey key) {
+        AzureBaseCredentials credential = AzureCredentialUtil.getCredential(null, key.credentialsId);
+        if (credential == null) {
+            return null;
+        }
+
+        TokenCredential tokenCredential = AzureCredentials.getTokenCredential(credential);
+
+        return new BlobServiceClientBuilder()
+                .credential(tokenCredential)
+                .endpoint(key.blobServiceEndpoint)
+                .httpClient(HttpClientRetriever.get())
+                .buildClient();
+    }
+
+    private static class CacheKey {
+        private final String credentialsId;
+        private final String blobServiceEndpoint;
+
+        CacheKey(String credentialsId, String blobServiceEndpoint) {
+            this.credentialsId = credentialsId;
+            this.blobServiceEndpoint = blobServiceEndpoint;
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (o == null || getClass() != o.getClass()) {
+                return false;
+            }
+            CacheKey cacheKey = (CacheKey) o;
+            return Objects.equals(credentialsId, cacheKey.credentialsId)
+                    && Objects.equals(blobServiceEndpoint, cacheKey.blobServiceEndpoint);
+        }
+
+        @Override
+        public int hashCode() {
+            return Objects.hash(credentialsId, blobServiceEndpoint);
+        }
+    }
+}