add cloudflare r2

README.md

@@ -61,6 +61,7 @@ Additionally, the plugin author may occasionally visit Obsidian official forum a
 ### S3
 
 - Tutorials / Examples:
+  - [Cloudflare R2](./docs/remote_services/s3_cloudflare_r2/README.md)
   - [MinIO](./docs/remote_services/s3_minio/README.md)
 - Prepare your S3 (-compatible) service information: [endpoint, region](https://docs.aws.amazon.com/general/latest/gr/s3.html), [access key id, secret access key](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/getting-your-credentials.html), bucket name. The bucket should be empty and solely for syncing a vault.
 - About CORS:

docs/remote_services/s3_cloudflare_r2/README.md

@@ -0,0 +1,27 @@
+# Cloudflare R2
+
+## Links
+
+<https://www.cloudflare.com/developer-platform/r2/>
+
+## Steps
+
+1. **Be aware that it may cost you money.**
+2. Create a Cloudflare account and enable R2 feature. **Credit card info might be required by Cloudflare**, though Cloudflare provides generous free tier and zero egress fee.
+3. Create a bucket.
+   ![](./s3_cloudflare_r2_create_bucket.png)
+4. Create an Access Key with "Object Read & Write" permission, and add specify to your created bucket. During the creation, you will also get the auto-generated secret key, and the endpoint address.
+   ![](./s3_cloudflare_r2_create_api_token.png)
+5. In remotely-save setting page, input the address / bucket / access key / secret key. **Region being set to `us-east-1` is sufficient.** Enable "Bypass CORS", because usually that's what you want.
+
+   Click "check connectivity". (If you encounter an issue and sure the info are correct, please upgrade remotely-save to **version >= 0.3.29** and try again.)
+
+   ![](./s3_cloudflare_r2_rs_settings.png)
+
+6. Sync!
+
+## And Issue Related To "Check Connectivity"
+
+If you encounter an issue and sure the info are correct, please upgrade remotely-save to **version >= 0.3.29** and try again.
+
+Cloudflare doesn't allow `HeadBucket` for access keys with "Object Read & Write". So it may be possible that checking connectivity is not ok but actual syncing is ok. New version >= 0.3.29 of the plugin fix this problem by using `ListObjects` instead of `HeadBucket`.