[filesystem][s3] Mirror s3.session-token to fs.s3a.session.token

docs/docs/maintenance/filesystems.mdx

@@ -453,6 +453,15 @@ Please refer to [Trino S3](https://trino.io/docs/current/object-storage/file-sys
 
 </Tabs>
 
+### Temporary Credentials
+
+When using temporary credentials (for example from AWS STS), also provide the session token
+together with the access key and secret key.
+
+```yaml
+s3.session-token: zzz
+```
+
 ### S3 Compliant Object Stores
 
 The S3 Filesystem also support using S3 compliant object stores such as MinIO, Tencent's COS and IBM's Cloud Object

paimon-filesystems/paimon-s3-impl/src/main/java/org/apache/paimon/s3/S3FileIO.java

@@ -51,6 +51,7 @@ public class S3FileIO extends HadoopCompliantFileIO {
     private static final String[][] MIRRORED_CONFIG_KEYS = {
         {"fs.s3a.access-key", "fs.s3a.access.key"},
         {"fs.s3a.secret-key", "fs.s3a.secret.key"},
+        {"fs.s3a.session-token", "fs.s3a.session.token"},
         {"fs.s3a.path-style-access", "fs.s3a.path.style.access"},
         {"fs.s3a.signer-type", "fs.s3a.signing-algorithm"}
     };

paimon-filesystems/paimon-s3-impl/src/test/java/org/apache/paimon/s3/S3FileIOConfigTest.java

@@ -0,0 +1,81 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you 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 org.apache.paimon.s3;
+
+import org.apache.paimon.catalog.CatalogContext;
+import org.apache.paimon.options.Options;
+
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.s3a.AWSCredentialProviderList;
+import org.apache.hadoop.fs.s3a.S3AFileSystem;
+import org.junit.jupiter.api.Test;
+import software.amazon.awssdk.auth.credentials.AwsCredentials;
+import software.amazon.awssdk.auth.credentials.AwsSessionCredentials;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+/**
+ * Tests for the Hadoop configuration that {@link S3FileIO} derives from catalog options. No S3
+ * backend is contacted: {@code fs.s3a.bucket.probe=0} skips the bucket existence check and the
+ * endpoint is unroutable.
+ */
+class S3FileIOConfigTest {
+
+    @Test
+    void testHyphenSessionTokenIsMirrored() throws Exception {
+        Options options = baseOptions();
+        options.set("s3.session-token", "hyphen-token");
+
+        S3AFileSystem fs = fileSystem(options, "paimon-hyphen-token-bucket");
+
+        assertThat(fs.getConf().get("fs.s3a.session.token")).isEqualTo("hyphen-token");
+        try (AWSCredentialProviderList providers = fs.shareCredentials("test")) {
+            AwsCredentials credentials = providers.resolveCredentials();
+            assertThat(credentials).isInstanceOf(AwsSessionCredentials.class);
+            assertThat(((AwsSessionCredentials) credentials).sessionToken())
+                    .isEqualTo("hyphen-token");
+        }
+    }
+
+    @Test
+    void testDotSessionTokenIsKept() throws Exception {
+        Options options = baseOptions();
+        options.set("s3.session.token", "dot-token");
+
+        S3AFileSystem fs = fileSystem(options, "paimon-dot-token-bucket");
+
+        assertThat(fs.getConf().get("fs.s3a.session.token")).isEqualTo("dot-token");
+    }
+
+    private static S3AFileSystem fileSystem(Options options, String bucket) throws Exception {
+        S3FileIO fileIO = new S3FileIO();
+        fileIO.configure(CatalogContext.create(options));
+        return (S3AFileSystem) fileIO.getFileSystem(new Path("s3://" + bucket + "/"));
+    }
+
+    private static Options baseOptions() {
+        Options options = new Options();
+        options.set("s3.bucket.probe", "0");
+        options.set("s3.endpoint", "http://localhost:1");
+        options.set("s3.endpoint.region", "us-east-1");
+        options.set("s3.access-key", "dummy-access-key");
+        options.set("s3.secret-key", "dummy-secret-key");
+        return options;
+    }
+}