terraform: Unmark provider configuration arguments

Before configuring a provider, we need to unmark the configuration
object, in case it includes any sensitive values. This is required
because configuration occurs over gRPC, which doesn't support sensitive
marks.

terraform/node_provider.go

@@ -68,8 +68,12 @@ func (n *NodeApplyableProvider) ValidateProvider(ctx EvalContext, provider provi
 		return diags
 	}
 
+	// If our config value contains any marked values, ensure those are
+	// stripped out before sending this to the provider
+	unmarkedConfigVal, _ := configVal.UnmarkDeep()
+
 	req := providers.PrepareProviderConfigRequest{
-		Config: configVal,
+		Config: unmarkedConfigVal,
 	}
 
 	validateResp := provider.PrepareProviderConfig(req)
@@ -109,10 +113,14 @@ func (n *NodeApplyableProvider) ConfigureProvider(ctx EvalContext, provider prov
 		return diags
 	}
 
+	// If our config value contains any marked values, ensure those are
+	// stripped out before sending this to the provider
+	unmarkedConfigVal, _ := configVal.UnmarkDeep()
+
 	// Allow the provider to validate and insert any defaults into the full
 	// configuration.
 	req := providers.PrepareProviderConfigRequest{
-		Config: configVal,
+		Config: unmarkedConfigVal,
 	}
 
 	// PrepareProviderConfig is only used for validation. We are intentionally
@@ -126,11 +134,11 @@ func (n *NodeApplyableProvider) ConfigureProvider(ctx EvalContext, provider prov
 	// If the provider returns something different, log a warning to help
 	// indicate to provider developers that the value is not used.
 	preparedCfg := prepareResp.PreparedConfig
-	if preparedCfg != cty.NilVal && !preparedCfg.IsNull() && !preparedCfg.RawEquals(configVal) {
+	if preparedCfg != cty.NilVal && !preparedCfg.IsNull() && !preparedCfg.RawEquals(unmarkedConfigVal) {
 		log.Printf("[WARN] PrepareProviderConfig from %q changed the config value, but that value is unused", n.Addr)
 	}
 
-	configDiags := ctx.ConfigureProvider(n.Addr, configVal)
+	configDiags := ctx.ConfigureProvider(n.Addr, unmarkedConfigVal)
 	diags = diags.Append(configDiags.InConfigBody(configBody))
 
 	return diags

terraform/node_provider_test.go

@@ -115,3 +115,77 @@ func TestNodeApplyableProviderExecute_unknownApply(t *testing.T) {
 		t.Errorf("wrong configuration value\ngot:  %#v\nwant: %#v", got, want)
 	}
 }
+
+func TestNodeApplyableProviderExecute_sensitive(t *testing.T) {
+	config := &configs.Provider{
+		Name: "foo",
+		Config: configs.SynthBody("", map[string]cty.Value{
+			"test_string": cty.StringVal("hello").Mark("sensitive"),
+		}),
+	}
+	provider := mockProviderWithConfigSchema(simpleTestSchema())
+	providerAddr := addrs.AbsProviderConfig{
+		Module:   addrs.RootModule,
+		Provider: addrs.NewDefaultProvider("foo"),
+	}
+
+	n := &NodeApplyableProvider{&NodeAbstractProvider{
+		Addr:   providerAddr,
+		Config: config,
+	}}
+
+	ctx := &MockEvalContext{ProviderProvider: provider}
+	ctx.installSimpleEval()
+	if err := n.Execute(ctx, walkApply); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if !ctx.ConfigureProviderCalled {
+		t.Fatal("should be called")
+	}
+
+	gotObj := ctx.ConfigureProviderConfig
+	if !gotObj.Type().HasAttribute("test_string") {
+		t.Fatal("configuration object does not have \"test_string\" attribute")
+	}
+	if got, want := gotObj.GetAttr("test_string"), cty.StringVal("hello"); !got.RawEquals(want) {
+		t.Errorf("wrong configuration value\ngot:  %#v\nwant: %#v", got, want)
+	}
+}
+
+func TestNodeApplyableProviderExecute_sensitiveValidate(t *testing.T) {
+	config := &configs.Provider{
+		Name: "foo",
+		Config: configs.SynthBody("", map[string]cty.Value{
+			"test_string": cty.StringVal("hello").Mark("sensitive"),
+		}),
+	}
+	provider := mockProviderWithConfigSchema(simpleTestSchema())
+	providerAddr := addrs.AbsProviderConfig{
+		Module:   addrs.RootModule,
+		Provider: addrs.NewDefaultProvider("foo"),
+	}
+
+	n := &NodeApplyableProvider{&NodeAbstractProvider{
+		Addr:   providerAddr,
+		Config: config,
+	}}
+
+	ctx := &MockEvalContext{ProviderProvider: provider}
+	ctx.installSimpleEval()
+	if err := n.Execute(ctx, walkValidate); err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	if !provider.PrepareProviderConfigCalled {
+		t.Fatal("should be called")
+	}
+
+	gotObj := provider.PrepareProviderConfigRequest.Config
+	if !gotObj.Type().HasAttribute("test_string") {
+		t.Fatal("configuration object does not have \"test_string\" attribute")
+	}
+	if got, want := gotObj.GetAttr("test_string"), cty.StringVal("hello"); !got.RawEquals(want) {
+		t.Errorf("wrong configuration value\ngot:  %#v\nwant: %#v", got, want)
+	}
+}