config: support for provider configs

config/config.go

@@ -12,8 +12,18 @@ import (
 // Config is the configuration that comes from loading a collection
 // of Terraform templates.
 type Config struct {
-	Variables map[string]Variable
+	ProviderConfigs map[string]*ProviderConfig
-	Resources []*Resource
+	Resources       []*Resource
+	Variables       map[string]Variable
+}
+
+// ProviderConfig is the configuration for a resource provider.
+//
+// For example, Terraform needs to set the AWS access keys for the AWS
+// resource provider.
+type ProviderConfig struct {
+	Config    map[string]interface{}
+	Variables map[string]InterpolatedVariable
 }
 
 // A resource represents a single Terraform resource in the configuration.

config/config_tree.go

@@ -66,6 +66,16 @@ func mergeConfig(c1, c2 *Config) (*Config, error) {
 		c.Variables[k] = v2
 	}
 
+	// Merge provider configs: If they collide, we just take the latest one
+	// for now. In the future, we might provide smarter merge functionality.
+	c.ProviderConfigs = make(map[string]*ProviderConfig)
+	for k, v := range c1.ProviderConfigs {
+		c.ProviderConfigs[k] = v
+	}
+	for k, v := range c2.ProviderConfigs {
+		c.ProviderConfigs[k] = v
+	}
+
 	// Merge resources: If they collide, we just take the latest one
 	// for now. In the future, we might provide smarter merge functionality.
 	resources := make(map[string]*Resource)

config/loader_libucl.go

@@ -36,6 +36,17 @@ func (t *libuclConfigurable) Config() (*Config, error) {
 	config := new(Config)
 	config.Variables = rawConfig.Variable
 
+	// Build the provider configs
+	providers := t.Object.Get("provider")
+	if providers != nil {
+		var err error
+		config.ProviderConfigs, err = loadProvidersLibucl(providers)
+		providers.Close()
+		if err != nil {
+			return nil, err
+		}
+	}
+
 	// Build the resources
 	resources := t.Object.Get("resource")
 	if resources != nil {
@@ -114,6 +125,52 @@ func loadFileLibucl(root string) (configurable, []string, error) {
 	return result, importPaths, nil
 }
 
+// LoadProvidersLibucl recurses into the given libucl object and turns
+// it into a mapping of provider configs.
+func loadProvidersLibucl(o *libucl.Object) (map[string]*ProviderConfig, error) {
+	objects := make(map[string]*libucl.Object)
+
+	// Iterate over all the "provider" blocks and get the keys along with
+	// their raw configuration objects. We'll parse those later.
+	iter := o.Iterate(false)
+	for o1 := iter.Next(); o1 != nil; o1 = iter.Next() {
+		iter2 := o1.Iterate(true)
+		for o2 := iter2.Next(); o2 != nil; o2 = iter2.Next() {
+			objects[o2.Key()] = o2
+			defer o2.Close()
+		}
+
+		o1.Close()
+		iter2.Close()
+	}
+	iter.Close()
+
+	// Go through each object and turn it into an actual result.
+	result := make(map[string]*ProviderConfig)
+	for n, o := range objects {
+		var config map[string]interface{}
+
+		if err := o.Decode(&config); err != nil {
+			return nil, err
+		}
+
+		walker := new(variableDetectWalker)
+		if err := reflectwalk.Walk(config, walker); err != nil {
+			return nil, fmt.Errorf(
+				"Error reading config for provider config %s: %s",
+				n,
+				err)
+		}
+
+		result[n] = &ProviderConfig{
+			Config:    config,
+			Variables: walker.Variables,
+		}
+	}
+
+	return result, nil
+}
+
 // Given a handle to a libucl object, this recurses into the structure
 // and pulls out a list of resources.
 //

config/loader_test.go

@@ -29,6 +29,11 @@ func TestLoadBasic(t *testing.T) {
 		t.Fatalf("bad:\n%s", actual)
 	}
 
+	actual = providerConfigsStr(c.ProviderConfigs)
+	if actual != strings.TrimSpace(basicProvidersStr) {
+		t.Fatalf("bad:\n%s", actual)
+	}
+
 	actual = resourcesStr(c.Resources)
 	if actual != strings.TrimSpace(basicResourcesStr) {
 		t.Fatalf("bad:\n%s", actual)
@@ -50,12 +55,49 @@ func TestLoadBasic_import(t *testing.T) {
 		t.Fatalf("bad:\n%s", actual)
 	}
 
+	actual = providerConfigsStr(c.ProviderConfigs)
+	if actual != strings.TrimSpace(importProvidersStr) {
+		t.Fatalf("bad:\n%s", actual)
+	}
+
 	actual = resourcesStr(c.Resources)
 	if actual != strings.TrimSpace(importResourcesStr) {
 		t.Fatalf("bad:\n%s", actual)
 	}
 }
 
+// This helper turns a provider configs field into a deterministic
+// string value for comparison in tests.
+func providerConfigsStr(pcs map[string]*ProviderConfig) string {
+	result := ""
+	for n, pc := range pcs {
+		result += fmt.Sprintf("%s\n", n)
+
+		for k, _ := range pc.Config {
+			result += fmt.Sprintf("  %s\n", k)
+		}
+
+		if len(pc.Variables) > 0 {
+			result += fmt.Sprintf("  vars\n")
+			for _, rawV := range pc.Variables {
+				kind := "unknown"
+				str := rawV.FullKey()
+
+				switch rawV.(type) {
+				case *ResourceVariable:
+					kind = "resource"
+				case *UserVariable:
+					kind = "user"
+				}
+
+				result += fmt.Sprintf("    %s: %s\n", kind, str)
+			}
+		}
+	}
+
+	return strings.TrimSpace(result)
+}
+
 // This helper turns a resources field into a deterministic
 // string value for comparison in tests.
 func resourcesStr(rs []*Resource) string {
@@ -113,6 +155,16 @@ func variablesStr(vs map[string]Variable) string {
 	return strings.TrimSpace(result)
 }
 
+const basicProvidersStr = `
+aws
+  access_key
+  secret_key
+do
+  api_key
+  vars
+    user: var.foo
+`
+
 const basicResourcesStr = `
 aws_security_group[firewall]
 aws_instance[web]
@@ -129,6 +181,11 @@ foo
   bar
 `
 
+const importProvidersStr = `
+aws
+  foo
+`
+
 const importResourcesStr = `
 aws_security_group[db]
 aws_security_group[web]

config/test-fixtures/basic.tf

@@ -3,6 +3,15 @@ variable "foo" {
     description = "bar";
 }
 
+provider "aws" {
+  access_key = "foo";
+  secret_key = "bar";
+}
+
+provider "do" {
+  api_key = "${var.foo}";
+}
+
 resource "aws_security_group" "firewall" {
 }
 

config/test-fixtures/import.tf

@@ -5,4 +5,8 @@ variable "foo" {
     description = "bar";
 }
 
+provider "aws" {
+    foo = "bar";
+}
+
 resource "aws_security_group" "web" {}

config/test-fixtures/import/one.tf

@@ -1,3 +1,7 @@
 variable "bar" {}
 
+provider "aws" {
+    bar = "baz";
+}
+
 resource "aws_security_group" "db" {}