[v3] Make PULUMI_FORCE_NEW_FROM_SUBTYPES the default (#3771)

Enables the functionality of `PULUMI_FORCE_NEW_FROM_SUBTYPES` by default
in v3. In v2, behavior is unchanged. In any version, setting
`PULUMI_FORCE_NEW_FROM_SUBTYPES` overrides the default behavior.

Closes #3006

Author: EronWright

README.md

@@ -60,12 +60,6 @@ quality and higher fidelity with the Azure platform.
 
 To learn how to configure credentials refer to the [Azure configuration options](https://www.pulumi.com/registry/packages/azure-native/installation-configuration/#configuration-options).
 
-## Other Configuration
-
-In addition to the configuration options in the official documentation linked above, the following environment variables can be used to tweak lower-level behavior of the provider:
-
-  - `PULUMI_FORCE_NEW_FROM_SUBTYPES`: if, after a change in your program, the provider does not replace a resource that should be replaced because it cannot be updated, setting this variable to `true` might allow the provider to infer the correct behavior. For more details please see PR #2970. We're planning to make this behavior the default in the future.
-
 ## Building
 
 See [contributing](CONTRIBUTING.md) for details on how to build and contribute to this provider.

provider/pkg/provider/diff.go

@@ -9,10 +9,12 @@ import (
 	"reflect"
 	"regexp"
 	"sort"
+	"strconv"
 	"strings"
 
 	"github.com/davegardnerisme/deephash"
 	"github.com/pulumi/pulumi-azure-native/v2/provider/pkg/resources"
+	"github.com/pulumi/pulumi-azure-native/v2/provider/pkg/version"
 	"github.com/pulumi/pulumi/pkg/v3/codegen"
 	"github.com/pulumi/pulumi/sdk/v3/go/common/resource"
 	"github.com/pulumi/pulumi/sdk/v3/go/common/util/logging"
@@ -285,7 +287,14 @@ func calculateDetailedDiff(resource *resources.AzureAPIResource, lookupType reso
 }
 
 func findForceNew(base string, props map[string]resources.AzureAPIProperty, replaceKeys codegen.StringSet) {
-	forceNewFromSubtypes := os.Getenv("PULUMI_FORCE_NEW_FROM_SUBTYPES") == "true"
+	var forceNewFromSubtypes bool
+	if v, ok := os.LookupEnv("PULUMI_FORCE_NEW_FROM_SUBTYPES"); ok {
+		forceNewFromSubtypes, _ = strconv.ParseBool(v)
+	} else {
+		// https://github.com/pulumi/pulumi-azure-native/issues/3006
+		forceNewFromSubtypes = version.GetVersion().Major >= 3
+	}
+
 	for propName, prop := range props {
 		if prop.ForceNew || (prop.ForceNewInferredFromReferencedTypes && forceNewFromSubtypes) {
 			name := propName

sdk/python/README.md

@@ -60,12 +60,6 @@ quality and higher fidelity with the Azure platform.
 
 To learn how to configure credentials refer to the [Azure configuration options](https://www.pulumi.com/registry/packages/azure-native/installation-configuration/#configuration-options).
 
-## Other Configuration
-
-In addition to the configuration options in the official documentation linked above, the following environment variables can be used to tweak lower-level behavior of the provider:
-
-  - `PULUMI_FORCE_NEW_FROM_SUBTYPES`: if, after a change in your program, the provider does not replace a resource that should be replaced because it cannot be updated, setting this variable to `true` might allow the provider to infer the correct behavior. For more details please see PR #2970. We're planning to make this behavior the default in the future.
-
 ## Building
 
 See [contributing](CONTRIBUTING.md) for details on how to build and contribute to this provider.