Update Environment-Variables.md

Environment-Variables.md

@@ -13,6 +13,37 @@ weed master
 # Weed prefix
 For `v`, `logtostderr`, `stderrthreshold`, `vmoudle`, `options`, `logdir`, `alsologtostderr`, `log_backtrace_at` , and `config_dir` you have to use `WEED_` as prefix for environment variable like this `WEED_CONFIG_DIR=/tmp`
 
+# S3 Admin Credentials
+For S3 API server, you can use standard AWS environment variables to set default admin credentials:
+
+```shell
+export AWS_ACCESS_KEY_ID=your_access_key
+export AWS_SECRET_ACCESS_KEY=your_secret_key
+weed s3 -filer=localhost:8888
+```
+
+These environment variables will supplement existing configuration by adding admin credentials when:
+- Both `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY` are set
+- No identity with the same access key already exists
+
+**Configuration Priority:**
+1. **File or Filer configuration** is loaded first (if provided)
+2. **Environment variables** are added second, supplementing the existing configuration
+3. Environment variables are **skipped** if an access key conflict exists
+
+This approach ensures that:
+- Existing S3 configuration files (with `admin_access` etc.) are preserved
+- Environment variables provide additional admin access without conflicts
+- AWS standard environment variables work seamlessly alongside existing setups
+
+The admin identity from environment variables will have:
+- Name: `admin-` followed by the access key (or first 8 characters if longer than 8)
+- Access Key: value of `AWS_ACCESS_KEY_ID`
+- Secret Key: value of `AWS_SECRET_ACCESS_KEY`
+- Permissions: Full admin access to all S3 operations
+
+This follows the standard AWS credential convention, making it compatible with existing AWS tooling and workflows.
+
 # Docker
 This is useful for using docker and docker compose  
 You have to override entrypoint to `weed` because defautl [entrypoint](https://github.com/seaweedfs/seaweedfs/blob/master/docker/entrypoint.sh) use default values for `volumeSizeLimitMB`, `volumePreallocate`, `mdir`, `dir`, and `max` and setting environment variables won't change these values.
@@ -39,3 +70,29 @@ services:
     entrypoint: weed
     command: master 
 ```
+
+## Docker Compose with S3 Admin Credentials
+```yaml
+version: '3.9'
+services:
+  filer:
+    image: chrislusf/seaweedfs:latest
+    ports:
+      - 8888:8888
+    environment:
+      # ... other filer environment variables
+    entrypoint: weed
+    command: filer -master=master:9333
+  
+  s3:
+    image: chrislusf/seaweedfs:latest
+    ports:
+      - 8333:8333
+    environment:
+      AWS_ACCESS_KEY_ID: s3admin
+      AWS_SECRET_ACCESS_KEY: s3secret
+    entrypoint: weed
+    command: s3 -filer=filer:8888
+    depends_on:
+      - filer
+```