Fixes to S3 compatibility page (#314)

Mention PostObject is implemented, fix english mistakes

Co-authored-by: Alex Auvolat <alex@adnab.me>
Reviewed-on: https://git.deuxfleurs.fr/Deuxfleurs/garage/pulls/314
Co-authored-by: Alex <alex@adnab.me>
Co-committed-by: Alex <alex@adnab.me>

doc/book/reference-manual/s3-compatibility.md

@@ -5,22 +5,26 @@ weight = 20
 
 ## DISCLAIMER
 
-**The compatibility list for other platforms is given only for information purposes and based on available documentation.** They are sometimes completed, in a best effort approach, with the source code and inputs from maintainers when documentation is lacking. We are not proactively monitoring new versions of each software, check the modification history to know when the page has been updated for the last time. Some entries will be inexact or outdated: for any serious decision, you must make your own tests.  
+**The compatibility list for other platforms is given only for informational
-**The official documentation of each project can be accessed by clicking on the project name in the column header.** 
+purposes and based on available documentation.** They are sometimes completed,
+in a best effort approach, with the source code and inputs from maintainers
+when documentation is lacking. We are not proactively monitoring new versions
+of each software: check the modification history to know when the page has been
+updated for the last time. Some entries will be inexact or outdated. For any
+serious decision, you must make your own tests.
+**The official documentation of each project can be accessed by clicking on the
+project name in the column header.**
 
-Feel free to open a PR to fix this table. Minio is missing because they do not provide a public S3 compatibility list.
+Feel free to open a PR to suggest fixes this table. Minio is missing because they do not provide a public S3 compatibility list.
 
 ## Update history
 
-  - 2022-02-07 - First version of this page
+- 2022-02-07 - First version of this page
-  - 2022-05-25 - Many Ceph S3 endpoints are not documented but implemented. Following a notification from the Ceph community, we added them.
+- 2022-05-25 - Many Ceph S3 endpoints are not documented but implemented. Following a notification from the Ceph community, we added them.
 
-## Endpoint implementation
 
-All APIs that are missing on Garage will return a 501 Not Implemented.
-Some `x-amz-` headers are not implemented.
 
-### Features
+## High-level features
 
 | Feature                      | Garage                           | [Openstack Swift](https://docs.openstack.org/swift/latest/s3_compat.html) | [Ceph Object Gateway](https://docs.ceph.com/en/latest/radosgw/s3/) | [Riak CS](https://docs.riak.com/riak/cs/2.1.1/references/apis/storage/s3/index.html) | [OpenIO](https://docs.openio.io/latest/source/arch-design/s3_compliancy.html) |
 |------------------------------|----------------------------------|-----------------|---------------|---------|-----|
@@ -30,7 +34,15 @@ Some `x-amz-` headers are not implemented.
 | [URL vhost-style](https://docs.aws.amazon.com/AmazonS3/latest/userguide/VirtualHosting.html#virtual-hosted-style-access) URL (eg. `bucket.host.tld/key`) |  ✅ Implemented | ❌| ✅| ✅ | ✅ |
 | [Presigned URLs](https://docs.aws.amazon.com/AmazonS3/latest/userguide/ShareObjectPreSignedURL.html) |  ✅ Implemented | ❌|  ✅ | ✅ |  ✅(❓) |
 
-*Note:* OpenIO does not says if it supports presigned URLs. Because it is part of signature v4 and they claim they support it without additional precisions, we suppose that OpenIO supports presigned URLs.
+*Note:* OpenIO does not says if it supports presigned URLs. Because it is part
+of signature v4 and they claim they support it without additional precisions,
+we suppose that OpenIO supports presigned URLs.
+
+
+## Endpoint implementation
+
+All endpoints that are missing on Garage will return a 501 Not Implemented.
+Some `x-amz-` headers are not implemented.
 
 ### Core endoints
 
@@ -48,12 +60,16 @@ Some `x-amz-` headers are not implemented.
 | [GetObject](https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetObject.html)                    | ✅ Implemented                      |  ✅ | ✅ | ✅ | ✅ |
 | [ListObjects](https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjects.html)                  | ✅ Implemented (see details below)   | ✅ | ✅ |  ✅ | ❌|
 | [ListObjectsV2](https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjectsV2.html)                | ✅ Implemented                      | ❌|  ✅  | ❌| ✅ |
-| [PostObject](https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPOST.html) (compatibility API)                   |  ❌ Missing                      | ❌| ✅ | ❌| ❌|
+| [PostObject](https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPOST.html)                  | ✅ Implemented                      | ❌| ✅ | ❌| ❌|
 | [PutObject](https://docs.aws.amazon.com/AmazonS3/latest/API/API_PutObject.html)                    | ✅ Implemented                      | ✅ | ✅ | ✅ | ✅ |
 
-**ListObjects:** Implemented, but there isn't a very good specification of what `encoding-type=url` covers so there might be some encoding bugs. In our implementation the url-encoded fields are in the same in ListObjects as they are in ListObjectsV2.
+**ListObjects:** Implemented, but there isn't a very good specification of what
+`encoding-type=url` covers so there might be some encoding bugs. In our
+implementation the url-encoded fields are in the same in ListObjects as they
+are in ListObjectsV2.
 
-*Note: Ceph API documentation is incomplete and miss at least HeadBucket and UploadPartCopy, but these endpoints are documented in [Red Hat Ceph Storage - Chapter 2. Ceph Object Gateway and the S3 API](https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/4/html/developer_guide/ceph-object-gateway-and-the-s3-api)*
+*Note: Ceph API documentation is incomplete and lacks at least HeadBucket and UploadPartCopy,
+but these endpoints are documented in [Red Hat Ceph Storage - Chapter 2. Ceph Object Gateway and the S3 API](https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/4/html/developer_guide/ceph-object-gateway-and-the-s3-api)*
 
 ### Multipart Upload endpoints
 
@@ -83,7 +99,7 @@ For more information, please refer to our [issue tracker](https://git.deuxfleurs
 
 **PutBucketWebsite:** Implemented, but only stores the index document suffix and the error document path. Redirects are not supported.
 
-*Note: Ceph radosgw has some support for static websites but it is different from Amazon one plus it does not implement its configuration endpoints.*
+*Note: Ceph radosgw has some support for static websites but it is different from the Amazon one. It also does not implement its configuration endpoints.*
 
 ### ACL, Policies endpoints
 
@@ -106,7 +122,7 @@ See Garage CLI reference manual to learn how to use Garage's permission system.
 
 ### Versioning, Lifecycle endpoints
 
-Garage does not support (yet) object versioning.
+Garage does not (yet) support object versioning.
 If you need this feature, please [share your use case in our dedicated issue](https://git.deuxfleurs.fr/Deuxfleurs/garage/issues/166).
 
 | Endpoint                     | Garage                           | [Openstack Swift](https://docs.openstack.org/swift/latest/s3_compat.html) | [Ceph Object Gateway](https://docs.ceph.com/en/latest/radosgw/s3/) | [Riak CS](https://docs.riak.com/riak/cs/2.1.1/references/apis/storage/s3/index.html) | [OpenIO](https://docs.openio.io/latest/source/arch-design/s3_compliancy.html) |
@@ -131,7 +147,10 @@ Please open an issue if you have a use case for replication.
 | [GetBucketReplication](https://docs.aws.amazon.com/AmazonS3/latest/API/API_GetBucketReplication.html) | ❌ Missing | ❌| ✅ | ❌| ❌|
 | [PutBucketReplication](https://docs.aws.amazon.com/AmazonS3/latest/API/API_PutBucketReplication.html) | ❌ Missing | ❌| ⚠ | ❌| ❌|
 
-*Note: Ceph documentation briefly says that Ceph supports [replication though the S3 API](https://docs.ceph.com/en/latest/radosgw/multisite-sync-policy/#s3-replication-api) but with some limitations. Additionaly, replication endpoints are not documented in the S3 compatibility page so I don't know what kind of support we can expect.*
+*Note: Ceph documentation briefly says that Ceph supports
+[replication though the S3 API](https://docs.ceph.com/en/latest/radosgw/multisite-sync-policy/#s3-replication-api)
+but with some limitations.
+Additionaly, replication endpoints are not documented in the S3 compatibility page so I don't know what kind of support we can expect.*
 
 ### Locking objects