test + doc changes

Author: virajjasani

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/util/TestStringUtils.java

@@ -519,36 +519,31 @@ public void testStringCollectionSplitByEquals() {
     Map<String, String> splitMap =
         StringUtils.getTrimmedStringCollectionSplitByEquals("");
     Assertions
-        .assertThat(splitMap.size())
+        .assertThat(splitMap)
         .describedAs("Map of key value pairs split by equals(=) and comma(,)")
-        .isEqualTo(0);
+        .hasSize(0);
 
     splitMap = StringUtils.getTrimmedStringCollectionSplitByEquals(null);
     Assertions
-        .assertThat(splitMap.size())
+        .assertThat(splitMap)
         .describedAs("Map of key value pairs split by equals(=) and comma(,)")
-        .isEqualTo(0);
+        .hasSize(0);
 
     splitMap = StringUtils.getTrimmedStringCollectionSplitByEquals(
         "element.first.key1 = element.first.val1");
-    Assertions
-        .assertThat(splitMap.size())
-        .describedAs("Map of key value pairs split by equals(=) and comma(,)")
-        .isEqualTo(1);
     Assertions
         .assertThat(splitMap)
         .describedAs("Map of key value pairs split by equals(=) and comma(,)")
+        .hasSize(1)
         .containsEntry("element.first.key1", "element.first.val1");
 
     splitMap = StringUtils.getTrimmedStringCollectionSplitByEquals(
         "element.xyz.key1 =element.abc.val1 , element.xyz.key2= element.abc.val2");
-    Assertions
-        .assertThat(splitMap.size())
-        .describedAs("Map of key value pairs split by equals(=) and comma(,)")
-        .isEqualTo(2);
+
     Assertions
         .assertThat(splitMap)
         .describedAs("Map of key value pairs split by equals(=) and comma(,)")
+        .hasSize(2)
         .containsEntry("element.xyz.key1", "element.abc.val1")
         .containsEntry("element.xyz.key2", "element.abc.val2");
 
@@ -559,13 +554,11 @@ public void testStringCollectionSplitByEquals() {
             + "element.abc.val5 ,\n \n \n "
             + " element.xyz.key6      =       element.abc.val6 \n , \n"
             + "element.xyz.key7=element.abc.val7,\n");
-    Assertions
-        .assertThat(splitMap.size())
-        .describedAs("Map of key value pairs split by equals(=) and comma(,)")
-        .isEqualTo(7);
+
     Assertions
         .assertThat(splitMap)
         .describedAs("Map of key value pairs split by equals(=) and comma(,)")
+        .hasSize(7)
         .containsEntry("element.xyz.key1", "element.abc.val1")
         .containsEntry("element.xyz.key2", "element.abc.val2")
         .containsEntry("element.xyz.key3", "element.abc.val3")

hadoop-tools/hadoop-aws/src/site/markdown/tools/hadoop-aws/aws_sdk_upgrade.md

@@ -66,6 +66,25 @@ The change in interface will mean that custom credential providers will need to
 implement `software.amazon.awssdk.auth.credentials.AwsCredentialsProvider` instead of
 `com.amazonaws.auth.AWSCredentialsProvider`.
 
+[HADOOP-18980](https://issues.apache.org/jira/browse/HADOOP-18980) introduces extended version of
+the credential provider remapping. `fs.s3a.aws.credentials.provider.mapping` can be used to
+list comma-separated key-value pairs of mapped credential providers that are separated by
+equal operator (=). The key can be used by `fs.s3a.aws.credentials.provider` config, and it
+will be translated into the specified value of credential provider class based on the key-value
+pair provided by this config.
+
+For example, if `fs.s3a.aws.credentials.provider.mapping` is set with value:
+
+    com.amazonaws.auth.AnonymousAWSCredentials=org.apache.hadoop.fs.s3a.AnonymousAWSCredentialsProvider,
+    com.amazonaws.auth.EC2ContainerCredentialsProviderWrapper=org.apache.hadoop.fs.s3a.auth.IAMInstanceCredentialsProvider,
+    com.amazonaws.auth.InstanceProfileCredentialsProvider=org.apache.hadoop.fs.s3a.auth.IAMInstanceCredentialsProvider
+
+With the above key-value pairs, if `fs.s3a.aws.credentials.provider` specifies
+`com.amazonaws.auth.AnonymousAWSCredentials`, it will be remapped to
+`org.apache.hadoop.fs.s3a.AnonymousAWSCredentialsProvider` by S3A while preparing
+AWS credential provider list.
+
+
 ### Original V1 `AWSCredentialsProvider` interface
 
 Note how the interface begins with the capitalized "AWS" acronym.

hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/TestS3AAWSCredentialsProvider.java

@@ -732,48 +732,42 @@ public void testStringCollectionSplitByEquals() {
         S3AUtils.getTrimmedStringCollectionSplitByEquals(
             configuration, "custom_key");
     Assertions
-        .assertThat(splitMap.size())
+        .assertThat(splitMap)
         .describedAs(
             "Map of key value pairs derived from config, split by equals(=) and comma(,)")
-        .isEqualTo(0);
+        .hasSize(0);
 
     splitMap =
         S3AUtils.getTrimmedStringCollectionSplitByEquals(
             configuration, "not_present");
     Assertions
-        .assertThat(splitMap.size())
+        .assertThat(splitMap)
         .describedAs(
             "Map of key value pairs derived from config, split by equals(=) and comma(,)")
-        .isEqualTo(0);
+        .hasSize(0);
 
     configuration.set("custom_key", "element.first.key1 = element.first.val1");
     splitMap = S3AUtils.getTrimmedStringCollectionSplitByEquals(
         configuration, "custom_key");
-    Assertions
-        .assertThat(splitMap.size())
-        .describedAs(
-            "Map of key value pairs derived from config, split by equals(=) and comma(,)")
-        .isEqualTo(1);
+
     Assertions
         .assertThat(splitMap)
         .describedAs(
             "Map of key value pairs derived from config, split by equals(=) and comma(,)")
+        .hasSize(1)
         .containsEntry("element.first.key1", "element.first.val1");
 
     configuration.set("custom_key",
         "element.xyz.key1 =element.abc.val1 , element.xyz.key2= element.abc.val2");
     splitMap =
         S3AUtils.getTrimmedStringCollectionSplitByEquals(
             configuration, "custom_key");
-    Assertions
-        .assertThat(splitMap.size())
-        .describedAs(
-            "Map of key value pairs derived from config, split by equals(=) and comma(,)")
-        .isEqualTo(2);
+
     Assertions
         .assertThat(splitMap)
         .describedAs(
             "Map of key value pairs derived from config, split by equals(=) and comma(,)")
+        .hasSize(2)
         .containsEntry("element.xyz.key1", "element.abc.val1")
         .containsEntry("element.xyz.key2", "element.abc.val2");
 
@@ -786,15 +780,12 @@ public void testStringCollectionSplitByEquals() {
             + "element.xyz.key7=element.abc.val7,\n");
     splitMap = S3AUtils.getTrimmedStringCollectionSplitByEquals(
         configuration, "custom_key");
-    Assertions
-        .assertThat(splitMap.size())
-        .describedAs(
-            "Map of key value pairs derived from config, split by equals(=) and comma(,)")
-        .isEqualTo(7);
+
     Assertions
         .assertThat(splitMap)
         .describedAs(
             "Map of key value pairs derived from config, split by equals(=) and comma(,)")
+        .hasSize(7)
         .containsEntry("element.xyz.key1", "element.abc.val1")
         .containsEntry("element.xyz.key2", "element.abc.val2")
         .containsEntry("element.xyz.key3", "element.abc.val3")