add s3 authentication method informations (#7674)

* add s3 authentication method informations

* add druid.s3.fileSessionCredentials related content

* remove authentication parameters to avoid confusion as it is more detailed in S3 Deep Storage page

* streamline s3 docs

docs/content/configuration/index.md

@@ -541,13 +541,14 @@ The below table shows some important configurations for S3. See [S3 Deep Storage
 
 |Property|Description|Default|
 |--------|-----------|-------|
-|`druid.s3.accessKey`|The access key to use to access S3.|none|
-|`druid.s3.secretKey`|The secret key to use to access S3.|none|
 |`druid.storage.bucket`|S3 bucket name.|none|
 |`druid.storage.baseKey`|S3 object key prefix for storage.|none|
 |`druid.storage.disableAcl`|Boolean flag for ACL. If this is set to `false`, the full control would be granted to the bucket owner. This may require to set additional permissions. See [S3 permissions settings](../development/extensions-core/s3.html#s3-permissions-settings).|false|
 |`druid.storage.archiveBucket`|S3 bucket name for archiving when running the *archive task*.|none|
 |`druid.storage.archiveBaseKey`|S3 object key prefix for archiving.|none|
+|`druid.storage.sse.type`|Server-side encryption type. Should be one of `s3`, `kms`, and `custom`. See the below [Server-side encryption section](../development/extensions-core/s3.html#server-side-encryption) for more details.|None|
+|`druid.storage.sse.kms.keyId`|AWS KMS key ID. This is used only when `druid.storage.sse.type` is `kms` and can be empty to use the default key ID.|None|
+|`druid.storage.sse.custom.base64EncodedKey`|Base64-encoded key. Should be specified if `druid.storage.sse.type` is `custom`.|None|
 |`druid.storage.useS3aSchema`|If true, use the "s3a" filesystem when using Hadoop-based ingestion. If false, the "s3n" filesystem will be used. Only affects Hadoop-based ingestion.|false|
 
 #### HDFS Deep Storage

docs/content/development/extensions-core/s3.md

@@ -41,14 +41,9 @@ As an example, to set the region to 'us-east-1' through system properties:
 
 |Property|Description|Default|
 |--------|-----------|-------|
-|`druid.s3.accessKey`|S3 access key.|Must be set.|
+|`druid.s3.accessKey`|S3 access key.See [S3 authentication methods](#s3-authentication-methods) for more details|Can be ommitted according to authentication methods chosen.|
-|`druid.s3.secretKey`|S3 secret key.|Must be set.|
+|`druid.s3.secretKey`|S3 secret key.See [S3 authentication methods](#s3-authentication-methods) for more details|Can be ommitted according to authentication methods chosen.|
-|`druid.storage.bucket`|Bucket to store in.|Must be set.|
+|`druid.s3.fileSessionCredentials`|Path to properties file containing `sessionToken`, `accessKey` and `secretKey` value. One key/value pair per line (format `key=value`). See [S3 authentication methods](#s3-authentication-methods) for more details |Can be ommitted according to authentication methods chosen.|
-|`druid.storage.baseKey`|Base key prefix to use, i.e. what directory.|Must be set.|
-|`druid.storage.disableAcl`|Boolean flag to disable ACL. If this is set to `false`, the full control would be granted to the bucket owner. This may require to set additional permissions. See [S3 permissions settings](#s3-permissions-settings).|false|
-|`druid.storage.sse.type`|Server-side encryption type. Should be one of `s3`, `kms`, and `custom`. See the below [Server-side encryption section](#server-side-encryption) for more details.|None|
-|`druid.storage.sse.kms.keyId`|AWS KMS key ID. This is used only when `druid.storage.sse.type` is `kms` and can be empty to use the default key ID.|None|
-|`druid.storage.sse.custom.base64EncodedKey`|Base64-encoded key. Should be specified if `druid.storage.sse.type` is `custom`.|None|
 |`druid.s3.protocol`|Communication protocol type to use when sending requests to AWS. `http` or `https` can be used. This configuration would be ignored if `druid.s3.endpoint.url` is filled with a URL with a different protocol.|`https`|
 |`druid.s3.disableChunkedEncoding`|Disables chunked encoding. See [AWS document](https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3Builder.html#disableChunkedEncoding--) for details.|false|
 |`druid.s3.enablePathStyleAccess`|Enables path style access. See [AWS document](https://docs.aws.amazon.com/AWSJavaSDK/latest/javadoc/com/amazonaws/services/s3/AmazonS3Builder.html#enablePathStyleAccess--) for details.|false|
@@ -59,12 +54,38 @@ As an example, to set the region to 'us-east-1' through system properties:
 |`druid.s3.proxy.port`|Port on the proxy host to connect through.|None|
 |`druid.s3.proxy.username`|User name to use when connecting through a proxy.|None|
 |`druid.s3.proxy.password`|Password to use when connecting through a proxy.|None|
+|`druid.storage.bucket`|Bucket to store in.|Must be set.|
+|`druid.storage.baseKey`|Base key prefix to use, i.e. what directory.|Must be set.|
+|`druid.storage.archiveBucket`|S3 bucket name for archiving when running the *archive task*.|none|
+|`druid.storage.archiveBaseKey`|S3 object key prefix for archiving.|none|
+|`druid.storage.disableAcl`|Boolean flag to disable ACL. If this is set to `false`, the full control would be granted to the bucket owner. This may require to set additional permissions. See [S3 permissions settings](#s3-permissions-settings).|false|
+|`druid.storage.sse.type`|Server-side encryption type. Should be one of `s3`, `kms`, and `custom`. See the below [Server-side encryption section](#server-side-encryption) for more details.|None|
+|`druid.storage.sse.kms.keyId`|AWS KMS key ID. This is used only when `druid.storage.sse.type` is `kms` and can be empty to use the default key ID.|None|
+|`druid.storage.sse.custom.base64EncodedKey`|Base64-encoded key. Should be specified if `druid.storage.sse.type` is `custom`.|None|
+|`druid.storage.useS3aSchema`|If true, use the "s3a" filesystem when using Hadoop-based ingestion. If false, the "s3n" filesystem will be used. Only affects Hadoop-based ingestion.|false|
 
 ### S3 permissions settings
 
 `s3:GetObject` and `s3:PutObject` are basically required for pushing/loading segments to/from S3.
 If `druid.storage.disableAcl` is set to `false`, then `s3:GetBucketAcl` and `s3:PutObjectAcl` are additionally required to set ACL for objects.
 
+### S3 authentication methods
+
+To connect to your S3 bucket (whether deep storage bucket or source bucket), Druid use the following credentials providers chain
+
+|order|type|details|
+|--------|-----------|-------|
+|1|Druid config file|Based on your runtime.properties if it contains values `druid.s3.accessKey` and `druid.s3.secretKey` |
+|2|Custom properties file| Based on custom properties file where you can supply `sessionToken`, `accessKey` and `secretKey` values. This file is provided to Druid through `druid.s3.fileSessionCredentials` propertie|
+|3|Environment variables|Based on environment variables `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY`|
+|4|Java system properties|Based on JVM properties `aws.accessKeyId` and `aws.secretKey` |
+|5|Profile informations|Based on credentials you may have on your druid instance (generally in `~/.aws/credentials`)|
+|6|Instance profile informations|Based on the instance profile you may have attached to your druid instance|
+
+You can find more informations about authentication method [here](https://docs.aws.amazon.com/fr_fr/sdk-for-java/v1/developer-guide/credentials.html)<br/>
+**Note :** *Order is important here as it indicates the precedence of authentication methods.<br/> 
+So if you are trying to use Instance profile informations, you **must not** set `druid.s3.accessKey` and `druid.s3.secretKey` in your Druid runtime.properties* 
+
 ## Server-side encryption
 
 You can enable [server-side encryption](https://docs.aws.amazon.com/AmazonS3/latest/dev/serv-side-encryption.html) by setting
@@ -102,3 +123,5 @@ shardSpecs are not specified, and, in this case, caching can be useful. Prefetch
 |prefetchTriggerBytes|Threshold to trigger prefetching s3 objects.|maxFetchCapacityBytes / 2|no|
 |fetchTimeout|Timeout for fetching an s3 object.|60000|no|
 |maxFetchRetry|Maximum retry for fetching an s3 object.|3|no|
+
+