Add NoCacheBlobStore

README.md

@@ -115,6 +115,7 @@ S3Proxy can modify its behavior based on middlewares:
 * [sharded backend containers](https://github.com/gaul/s3proxy/wiki/Middleware-sharded-backend)
 * [storage class override](https://github.com/gaul/s3proxy/wiki/Middleware-storage-class-override)
 * [user metadata replacer](https://github.com/gaul/s3proxy/wiki/Middleware-user-metadata-replacer)
+* [no cache override](https://github.com/gaul/s3proxy/wiki/Middleware-no-cache)
 
 ## SSL Support
 

src/main/java/org/gaul/s3proxy/Main.java

@@ -314,6 +314,14 @@ public final class Main {
             blobStore = LatencyBlobStore.newLatencyBlobStore(blobStore, latencies, speeds);
         }
 
+        String noCacheBlobStore = properties.getProperty(
+              S3ProxyConstants.PROPERTY_NO_CACHE_BLOBSTORE);
+        if  ("true".equalsIgnoreCase(noCacheBlobStore)) {
+            System.err.println("Using no-cache storage backend middleware");
+            blobStore = NoCacheBlobStore
+                    .newNoCacheBlobStore(blobStore);
+        }
+
         return blobStore;
     }
 

src/main/java/org/gaul/s3proxy/NoCacheBlobStore.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright 2014-2025 Andrew Gaul <andrew@gaul.org>
+ *
+ * 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
+ *
+ * https://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.gaul.s3proxy;
+
+import org.jclouds.blobstore.BlobStore;
+import org.jclouds.blobstore.domain.Blob;
+import org.jclouds.blobstore.options.GetOptions;
+import org.jclouds.blobstore.util.ForwardingBlobStore;
+
+/**
+ * BlobStore which drops eTag or date based cache options from object requests.
+ * This is useful as the JClouds library does not fully support the proxying of HTTP 304 responses.
+ */
+final class NoCacheBlobStore extends ForwardingBlobStore {
+
+    private NoCacheBlobStore(BlobStore blobStore) {
+        super(blobStore);
+    }
+
+    public static BlobStore newNoCacheBlobStore(BlobStore blobStore) {
+        return new NoCacheBlobStore(blobStore);
+    }
+
+    @Override
+    public Blob getBlob(String containerName, String name) {
+        return getBlob(containerName, name, new GetOptions());
+    }
+
+    @Override
+    public Blob getBlob(String containerName, String name, GetOptions getOptions) {
+        return super.getBlob(containerName, name, resetCacheHeaders(getOptions));
+    }
+
+    static GetOptions resetCacheHeaders(GetOptions options) {
+        if (options.getIfMatch() != null || options.getIfNoneMatch() != null ||
+            options.getIfModifiedSince() != null ||  options.getIfUnmodifiedSince() != null) {
+              // as there is no exposed method to reset just the cache headers, a copy is used
+            GetOptions optionsNoCache = new GetOptions();
+            for (String range : options.getRanges()) {
+                String[] ranges = range.split("-", 2);
+                if (ranges[0].isEmpty()) {
+                    optionsNoCache.tail(Long.parseLong(ranges[1]));
+                } else if (ranges[1].isEmpty()) {
+                    optionsNoCache.startAt(Long.parseLong(ranges[0]));
+                } else {
+                    optionsNoCache.range(Long.parseLong(ranges[0]), Long.parseLong(ranges[1]));
+                }
+            }
+            return optionsNoCache;
+        }
+        return options;
+    }
+
+}

src/main/java/org/gaul/s3proxy/S3ProxyConstants.java

@@ -138,6 +138,9 @@ public final class S3ProxyConstants {
     public static final String PROPERTY_LATENCY =
             "s3proxy.latency-blobstore";
 
+    public static final String PROPERTY_NO_CACHE_BLOBSTORE =
+            "s3proxy.no-cache-blobstore";
+
     static final String PROPERTY_ALT_JCLOUDS_PREFIX = "alt.";
 
     private S3ProxyConstants() {

src/main/resources/run-docker-container.sh

@@ -25,6 +25,7 @@ exec java \
     -Ds3proxy.encrypted-blobstore-salt="${S3PROXY_ENCRYPTED_BLOBSTORE_SALT}" \
     -Ds3proxy.v4-max-non-chunked-request-size="${S3PROXY_V4_MAX_NON_CHUNKED_REQ_SIZE:-134217728}" \
     -Ds3proxy.read-only-blobstore="${S3PROXY_READ_ONLY_BLOBSTORE:-false}" \
+    -Ds3proxy.no-cache-blobstore="${S3PROXY_NO_CACHE_BLOBSTORE:-false}" \
     -Ds3proxy.maximum-timeskew="${S3PROXY_MAXIMUM_TIMESKEW}" \
     -Ds3proxy.service-path="${S3PROXY_SERVICE_PATH}" \
     -Djclouds.provider="${JCLOUDS_PROVIDER}" \

src/test/java/org/gaul/s3proxy/NoCacheBlobStoreTest.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright 2014-2025 Andrew Gaul <andrew@gaul.org>
+ *
+ * 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
+ *
+ * https://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.gaul.s3proxy;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+import java.time.Instant;
+import java.util.Date;
+
+import org.jclouds.blobstore.options.GetOptions;
+import org.junit.jupiter.api.Test;
+
+public final class NoCacheBlobStoreTest {
+    @Test
+    public void testResetCacheHeadersKeepRange() {
+        var options = GetOptions.Builder.range(1, 5);
+        var optionsResult = NoCacheBlobStore.resetCacheHeaders(options);
+        assertThat(optionsResult.getRanges()).isEqualTo(options.getRanges());
+    }
+
+    @Test
+    public void testResetCacheHeadersKeepTail() {
+        var options = GetOptions.Builder.range(1, 5).tail(3).startAt(10);
+        var optionsResult = NoCacheBlobStore.resetCacheHeaders(options);
+        assertThat(optionsResult.getRanges()).isEqualTo(options.getRanges());
+    }
+
+    @Test
+    public void testResetCacheHeadersRangeDropCache() {
+        var options = GetOptions.Builder
+                .range(1, 5)
+                .tail(3)
+                .startAt(10)
+                .ifETagDoesntMatch("abc")
+                .ifModifiedSince(Date.from(Instant.EPOCH));
+        var optionsResult = NoCacheBlobStore.resetCacheHeaders(options);
+        assertThat(optionsResult.getRanges()).isEqualTo(options.getRanges());
+        assertThat(optionsResult.getIfNoneMatch()).isEqualTo(null);
+        assertThat(optionsResult.getIfModifiedSince()).isEqualTo((Date) null);
+    }
+
+    @Test
+    public void testResetCacheHeadersNoRange() {
+        var options = GetOptions.Builder
+                .ifETagMatches("abc")
+                .ifUnmodifiedSince(Date.from(Instant.EPOCH));
+        var optionsResult = NoCacheBlobStore.resetCacheHeaders(options);
+        assertThat(optionsResult.getRanges()).isEqualTo(options.getRanges());
+        assertThat(optionsResult.getIfMatch()).isEqualTo(null);
+        assertThat(optionsResult.getIfUnmodifiedSince()).isEqualTo((Date) null);
+    }
+}