jsonconfig: Improve provider configuration output

When rendering configuration as JSON, we have a single map of provider
configurations at the top level, since these are globally applicable.
Each resource has an opaque key into this map which points at the
configuration data for the provider.

This commit fixes two bugs in this implementation:

- Resources in non-root modules had an invalid provider config key,
  which meant that there was never a valid reference to the provider
  config block. These keys were prefixed with the local module name
  instead of the path to the module. This is now corrected.

- Modules with passed provider configs would point to either an empty
  provider config block or one which is not present at all. This has
  been fixed so that these resources point to the provider config block
  from the calling module (or wherever up the module tree it was
  originally defined).

We also add a "full_name" key-value pair to the provider config block,
with the entire fully-qualified provider name including hostname and
namespace.

Author: alisdair

internal/command/jsonconfig/config.go

@@ -27,10 +27,12 @@ type config struct {
 // module boundaries.
 type providerConfig struct {
 	Name              string                 `json:"name,omitempty"`
+	FullName          string                 `json:"full_name,omitempty"`
 	Alias             string                 `json:"alias,omitempty"`
 	VersionConstraint string                 `json:"version_constraint,omitempty"`
 	ModuleAddress     string                 `json:"module_address,omitempty"`
 	Expressions       map[string]interface{} `json:"expressions,omitempty"`
+	parentKey         string
 }
 
 type module struct {
@@ -120,14 +122,22 @@ func Marshal(c *configs.Config, schemas *terraform.Schemas) ([]byte, error) {
 
 	pcs := make(map[string]providerConfig)
 	marshalProviderConfigs(c, schemas, pcs)
-	output.ProviderConfigs = pcs
 
 	rootModule, err := marshalModule(c, schemas, "")
 	if err != nil {
 		return nil, err
 	}
 	output.RootModule = rootModule
 
+	normalizeModuleProviderKeys(&rootModule, pcs)
+
+	for name, pc := range pcs {
+		if pc.parentKey != "" {
+			delete(pcs, name)
+		}
+	}
+	output.ProviderConfigs = pcs
+
 	ret, err := json.Marshal(output)
 	return ret, err
 }
@@ -154,6 +164,7 @@ func marshalProviderConfigs(
 
 		p := providerConfig{
 			Name:          pc.Name,
+			FullName:      providerFqn.String(),
 			Alias:         pc.Alias,
 			ModuleAddress: c.Path.String(),
 			Expressions:   marshalExpressions(pc.Config, schema),
@@ -176,6 +187,30 @@ func marshalProviderConfigs(
 	// Ensure that any required providers with no associated configuration
 	// block are included in the set.
 	for k, pr := range c.Module.ProviderRequirements.RequiredProviders {
+		// If a provider has aliases defined, process those first.
+		for _, alias := range pr.Aliases {
+			// If there exists a value for this provider, we have nothing to add
+			// to it, so skip.
+			key := opaqueProviderKey(alias.StringCompact(), c.Path.String())
+			if _, exists := m[key]; exists {
+				continue
+			}
+			// Given no provider configuration block exists, the only fields we can
+			// fill here are the local name, FQN, module address, and version
+			// constraints.
+			p := providerConfig{
+				Name:          pr.Name,
+				FullName:      pr.Type.String(),
+				ModuleAddress: c.Path.String(),
+			}
+
+			if vc, ok := reqs[pr.Type]; ok {
+				p.VersionConstraint = getproviders.VersionConstraintsString(vc)
+			}
+
+			m[key] = p
+		}
+
 		// If there exists a value for this provider, we have nothing to add
 		// to it, so skip.
 		key := opaqueProviderKey(k, c.Path.String())
@@ -188,6 +223,7 @@ func marshalProviderConfigs(
 		// constraints.
 		p := providerConfig{
 			Name:          pr.Name,
+			FullName:      pr.Type.String(),
 			ModuleAddress: c.Path.String(),
 		}
 
@@ -199,7 +235,53 @@ func marshalProviderConfigs(
 	}
 
 	// Must also visit our child modules, recursively.
-	for _, cc := range c.Children {
+	for name, mc := range c.Module.ModuleCalls {
+		// Keys in c.Children are guaranteed to match those in c.Module.ModuleCalls
+		cc := c.Children[name]
+
+		// Add provider config map entries for passed provider configs,
+		// pointing at the passed configuration
+		for _, ppc := range mc.Providers {
+			// These provider names include aliases, if set
+			moduleProviderName := ppc.InChild.String()
+			parentProviderName := ppc.InParent.String()
+
+			// Look up the provider FQN from the module context, using the non-aliased local name
+			providerFqn := cc.ProviderForConfigAddr(addrs.LocalProviderConfig{LocalName: ppc.InChild.Name})
+
+			// The presence of passed provider configs means that we cannot have
+			// any configuration expressions or version constraints here
+			p := providerConfig{
+				Name:          moduleProviderName,
+				FullName:      providerFqn.String(),
+				ModuleAddress: cc.Path.String(),
+			}
+
+			key := opaqueProviderKey(moduleProviderName, cc.Path.String())
+			parentKey := opaqueProviderKey(parentProviderName, cc.Parent.Path.String())
+
+			// Traverse up the module call tree until we find the provider
+			// configuration which has no linked parent config. This is then
+			// the source of the configuration used in this module call, so
+			// we link to it directly
+			for {
+				parent, exists := m[parentKey]
+				if !exists {
+					break
+				}
+				p.parentKey = parentKey
+				parentKey = parent.parentKey
+				if parentKey == "" {
+					break
+				}
+			}
+
+			m[key] = p
+		}
+
+		// Finally, marshal any other provider configs within the called module.
+		// It is safe to do this last because it is invalid to configure a
+		// provider which has passed provider configs in the module call.
 		marshalProviderConfigs(cc, schemas, m)
 	}
 }
@@ -319,7 +401,9 @@ func marshalModuleCall(c *configs.Config, mc *configs.ModuleCall, schemas *terra
 	}
 
 	ret.Expressions = marshalExpressions(mc.Config, schema)
-	module, _ := marshalModule(c, schemas, mc.Name)
+
+	module, _ := marshalModule(c, schemas, c.Path.String())
+
 	ret.Module = module
 
 	if len(mc.DependsOn) > 0 {
@@ -342,11 +426,12 @@ func marshalModuleCall(c *configs.Config, mc *configs.ModuleCall, schemas *terra
 func marshalResources(resources map[string]*configs.Resource, schemas *terraform.Schemas, moduleAddr string) ([]resource, error) {
 	var rs []resource
 	for _, v := range resources {
+		providerConfigKey := opaqueProviderKey(v.ProviderConfigAddr().StringCompact(), moduleAddr)
 		r := resource{
 			Address:           v.Addr().String(),
 			Type:              v.Type,
 			Name:              v.Name,
-			ProviderConfigKey: opaqueProviderKey(v.ProviderConfigAddr().StringCompact(), moduleAddr),
+			ProviderConfigKey: providerConfigKey,
 		}
 
 		switch v.Mode {
@@ -416,6 +501,23 @@ func marshalResources(resources map[string]*configs.Resource, schemas *terraform
 	return rs, nil
 }
 
+// Flatten all resource provider keys in a module and its descendents, such
+// that any resources from providers using a configuration passed through the
+// module call have a direct refernce to that provider configuration.
+func normalizeModuleProviderKeys(m *module, pcs map[string]providerConfig) {
+	for i, r := range m.Resources {
+		if pc, exists := pcs[r.ProviderConfigKey]; exists {
+			if _, hasParent := pcs[pc.parentKey]; hasParent {
+				m.Resources[i].ProviderConfigKey = pc.parentKey
+			}
+		}
+	}
+
+	for _, mc := range m.ModuleCalls {
+		normalizeModuleProviderKeys(&mc.Module, pcs)
+	}
+}
+
 // opaqueProviderKey generates a unique absProviderConfig-like string from the module
 // address and provider
 func opaqueProviderKey(provider string, addr string) (key string) {

internal/command/testdata/show-json-sensitive/output.json

@@ -164,6 +164,7 @@
         "provider_config": {
             "test": {
                 "name": "test",
+                "full_name": "registry.terraform.io/hashicorp/test",
                 "expressions": {
                     "region": {
                         "constant_value": "somewhere"

internal/command/testdata/show-json/basic-create/output.json

@@ -152,6 +152,7 @@
         "provider_config": {
             "test": {
                 "name": "test",
+                "full_name": "registry.terraform.io/hashicorp/test",
                 "expressions": {
                     "region": {
                         "constant_value": "somewhere"

internal/command/testdata/show-json/modules/output.json

@@ -224,7 +224,7 @@
                                 "mode": "managed",
                                 "type": "test_instance",
                                 "name": "test",
-                                "provider_config_key": "module_test_bar:test",
+                                "provider_config_key": "module.module_test_bar:test",
                                 "expressions": {
                                     "ami": {
                                         "references": [
@@ -265,7 +265,7 @@
                                 "mode": "managed",
                                 "type": "test_instance",
                                 "name": "test",
-                                "provider_config_key": "module_test_foo:test",
+                                "provider_config_key": "module.module_test_foo:test",
                                 "expressions": {
                                     "ami": {
                                         "references": [
@@ -291,7 +291,8 @@
         "provider_config": {
             "module.module_test_foo:test": {
                 "module_address": "module.module_test_foo",
-                "name": "test"
+                "name": "test",
+                "full_name": "registry.terraform.io/hashicorp/test"
             }
         }
     }

internal/command/testdata/show-json/nested-modules/output.json

@@ -68,7 +68,7 @@
                       "mode": "managed",
                       "type": "test_instance",
                       "name": "test",
-                      "provider_config_key": "more:test",
+                      "provider_config_key": "module.my_module.module.more:test",
                       "expressions": {
                         "ami": {
                           "references": [

internal/command/testdata/show-json/provider-aliasing/child/main.tf

@@ -0,0 +1,26 @@
+terraform {
+  required_providers {
+    test = {
+      source                = "hashicorp/test"
+      configuration_aliases = [test, test.second]
+    }
+  }
+}
+
+resource "test_instance" "test_primary" {
+  ami      = "primary"
+  provider = test
+}
+
+resource "test_instance" "test_secondary" {
+  ami      = "secondary"
+  provider = test.second
+}
+
+module "grandchild" {
+  source = "./nested"
+  providers = {
+    test     = test
+    test.alt = test.second
+  }
+}

internal/command/testdata/show-json/provider-aliasing/child/nested/main.tf

@@ -0,0 +1,18 @@
+terraform {
+  required_providers {
+    test = {
+      source                = "hashicorp/test"
+      configuration_aliases = [test, test.alt]
+    }
+  }
+}
+
+resource "test_instance" "test_main" {
+  ami      = "main"
+  provider = test
+}
+
+resource "test_instance" "test_alternate" {
+  ami      = "secondary"
+  provider = test.alt
+}

internal/command/testdata/show-json/provider-aliasing/main.tf

@@ -0,0 +1,34 @@
+provider "test" {
+  region = "somewhere"
+}
+
+provider "test" {
+  alias  = "backup"
+  region = "elsewhere"
+}
+
+resource "test_instance" "test" {
+  ami      = "foo"
+  provider = test
+}
+
+resource "test_instance" "test_backup" {
+  ami      = "foo-backup"
+  provider = test.backup
+}
+
+module "child" {
+  source = "./child"
+  providers = {
+    test        = test
+    test.second = test.backup
+  }
+}
+
+module "sibling" {
+  source = "./child"
+  providers = {
+    test        = test
+    test.second = test
+  }
+}