provider configuration

Author: raphaeltm

docs/concepts/defang-byoc.md

@@ -15,6 +15,18 @@ Defang does not install or run any Defang or third party services at runtime.
 Defang does run the Defang build service to build your container images, which terminates after every build.
 :::
 
+### Configuration
+
+The Defang CLI can be configured to deploy to a cloud provider either by using the `--provider` flag or by setting the `DEFANG_PROVIDER` environment variable. For example:
+
+```bash
+# Supported provider values: auto, aws
+# Default is auto, which deploys to the Defang Playground
+$ defang up --provider=aws
+# or
+$ export DEFANG_PROVIDER=aws
+```
+
 ## AWS
 
 :::info

docs/providers/aws/aws.md

@@ -20,10 +20,12 @@ Getting started with the Defang BYOC AWS Provider is easy. Make sure you have pr
 If you have the aws CLI installed, you should be able to successfully run `aws sts get-caller-identity` and see your account ID.
 :::
 
-Use the `--provider=aws` flag to tell the Defang CLI to use the AWS Provider.
+Use the `--provider=aws` flag to tell the Defang CLI to use the AWS Provider or set the `DEFANG_PROVIDER` environment variable to `aws`.
 
 ```bash
 $ defang up --provider=aws
+# or
+$ export DEFANG_PROVIDER=aws
 ```
 
 :::warning