terraform: Context introduction

config/config.go

@@ -5,6 +5,8 @@ package config
 import (
 	"fmt"
 	"strings"
+
+	"github.com/hashicorp/terraform/helper/multierror"
 )
 
 // Config is the configuration that comes from loading a collection
@@ -131,7 +133,7 @@ func (c *Config) Validate() error {
 	}
 
 	if len(errs) > 0 {
-		return &MultiError{Errors: errs}
+		return &multierror.Error{Errors: errs}
 	}
 
 	return nil

helper/multierror/error.go

@@ -1,18 +1,18 @@
-package config
+package multierror
 
 import (
 	"fmt"
 	"strings"
 )
 
-// MultiError is an error type to track multiple errors. This is used to
+// Error is an error type to track multiple errors. This is used to
 // accumulate errors in cases such as configuration parsing, and returning
 // them as a single error.
-type MultiError struct {
+type Error struct {
 	Errors []error
 }
 
-func (e *MultiError) Error() string {
+func (e *Error) Error() string {
 	points := make([]string, len(e.Errors))
 	for i, err := range e.Errors {
 		points[i] = fmt.Sprintf("* %s", err)
@@ -23,18 +23,18 @@ func (e *MultiError) Error() string {
 		len(e.Errors), strings.Join(points, "\n"))
 }
 
-// MultiErrorAppend is a helper function that will append more errors
+// ErrorAppend is a helper function that will append more errors
-// onto a MultiError in order to create a larger multi-error. If the
+// onto a Error in order to create a larger multi-error. If the
-// original error is not a MultiError, it will be turned into one.
+// original error is not a Error, it will be turned into one.
-func MultiErrorAppend(err error, errs ...error) *MultiError {
+func ErrorAppend(err error, errs ...error) *Error {
 	if err == nil {
-		err = new(MultiError)
+		err = new(Error)
 	}
 
 	switch err := err.(type) {
-	case *MultiError:
+	case *Error:
 		if err == nil {
-			err = new(MultiError)
+			err = new(Error)
 		}
 
 		err.Errors = append(err.Errors, errs...)
@@ -43,7 +43,7 @@ func MultiErrorAppend(err error, errs ...error) *MultiError {
 		newErrs := make([]error, len(errs)+1)
 		newErrs[0] = err
 		copy(newErrs[1:], errs)
-		return &MultiError{
+		return &Error{
 			Errors: newErrs,
 		}
 	}

helper/multierror/error_test.go

@@ -1,19 +1,19 @@
-package config
+package multierror
 
 import (
 	"errors"
 	"testing"
 )
 
-func TestMultiError_Impl(t *testing.T) {
+func TestError_Impl(t *testing.T) {
 	var raw interface{}
-	raw = &MultiError{}
+	raw = &Error{}
 	if _, ok := raw.(error); !ok {
-		t.Fatal("MultiError must implement error")
+		t.Fatal("Error must implement error")
 	}
 }
 
-func TestMultiErrorError(t *testing.T) {
+func TestErrorError(t *testing.T) {
 	expected := `2 error(s) occurred:
 
 * foo
@@ -24,32 +24,32 @@ func TestMultiErrorError(t *testing.T) {
 		errors.New("bar"),
 	}
 
-	multi := &MultiError{errors}
+	multi := &Error{errors}
 	if multi.Error() != expected {
 		t.Fatalf("bad: %s", multi.Error())
 	}
 }
 
-func TestMultiErrorAppend_MultiError(t *testing.T) {
+func TestErrorAppend_Error(t *testing.T) {
-	original := &MultiError{
+	original := &Error{
 		Errors: []error{errors.New("foo")},
 	}
 
-	result := MultiErrorAppend(original, errors.New("bar"))
+	result := ErrorAppend(original, errors.New("bar"))
 	if len(result.Errors) != 2 {
 		t.Fatalf("wrong len: %d", len(result.Errors))
 	}
 
-	original = &MultiError{}
+	original = &Error{}
-	result = MultiErrorAppend(original, errors.New("bar"))
+	result = ErrorAppend(original, errors.New("bar"))
 	if len(result.Errors) != 1 {
 		t.Fatalf("wrong len: %d", len(result.Errors))
 	}
 }
 
-func TestMultiErrorAppend_NonMultiError(t *testing.T) {
+func TestErrorAppend_NonError(t *testing.T) {
 	original := errors.New("foo")
-	result := MultiErrorAppend(original, errors.New("bar"))
+	result := ErrorAppend(original, errors.New("bar"))
 	if len(result.Errors) != 2 {
 		t.Fatalf("wrong len: %d", len(result.Errors))
 	}

terraform/context.go

@@ -0,0 +1,69 @@
+package terraform
+
+import (
+	"github.com/hashicorp/terraform/config"
+	"github.com/hashicorp/terraform/helper/multierror"
+)
+
+// Context represents all the context that Terraform needs in order to
+// perform operations on infrastructure. This structure is built using
+// ContextOpts and NewContext. See the documentation for those.
+//
+// Additionally, a context can be created from a Plan using Plan.Context.
+type Context struct {
+	config    *config.Config
+	diff      *Diff
+	hooks     []Hook
+	state     *State
+	providers map[string]ResourceProviderFactory
+	variables map[string]string
+}
+
+// ContextOpts are the user-creatable configuration structure to create
+// a context with NewContext.
+type ContextOpts struct {
+	Config    *config.Config
+	Diff      *Diff
+	Hooks     []Hook
+	State     *State
+	Providers map[string]ResourceProviderFactory
+	Variables map[string]string
+}
+
+// NewContext creates a new context.
+//
+// Once a context is created, the pointer values within ContextOpts should
+// not be mutated in any way, since the pointers are copied, not the values
+// themselves.
+func NewContext(opts *ContextOpts) *Context {
+	return &Context{
+		config:    opts.Config,
+		diff:      opts.Diff,
+		hooks:     opts.Hooks,
+		state:     opts.State,
+		providers: opts.Providers,
+		variables: opts.Variables,
+	}
+}
+
+// Validate validates the configuration and returns any warnings or errors.
+func (c *Context) Validate() ([]string, []error) {
+	var rerr *multierror.Error
+
+	// Validate the configuration itself
+	if err := c.config.Validate(); err != nil {
+		rerr = multierror.ErrorAppend(rerr, err)
+	}
+
+	// Validate the user variables
+	if errs := smcUserVariables(c.config, c.variables); len(errs) > 0 {
+		rerr = multierror.ErrorAppend(rerr, errs...)
+	}
+
+	var errs []error
+	if rerr != nil && len(rerr.Errors) > 0 {
+		errs = rerr.Errors
+	}
+
+	return nil, errs
+}

terraform/context_test.go

@@ -0,0 +1,54 @@
+package terraform
+
+import (
+	"testing"
+)
+
+func TestContextValidate(t *testing.T) {
+	config := testConfig(t, "validate-good")
+	c := testContext(t, &ContextOpts{
+		Config: config,
+	})
+
+	w, e := c.Validate()
+	if len(w) > 0 {
+		t.Fatalf("bad: %#v", w)
+	}
+	if len(e) > 0 {
+		t.Fatalf("bad: %#v", e)
+	}
+}
+
+func TestContextValidate_badVar(t *testing.T) {
+	config := testConfig(t, "validate-bad-var")
+	c := testContext(t, &ContextOpts{
+		Config: config,
+	})
+
+	w, e := c.Validate()
+	if len(w) > 0 {
+		t.Fatalf("bad: %#v", w)
+	}
+	if len(e) == 0 {
+		t.Fatalf("bad: %#v", e)
+	}
+}
+
+func TestContextValidate_requiredVar(t *testing.T) {
+	config := testConfig(t, "validate-required-var")
+	c := testContext(t, &ContextOpts{
+		Config: config,
+	})
+
+	w, e := c.Validate()
+	if len(w) > 0 {
+		t.Fatalf("bad: %#v", w)
+	}
+	if len(e) == 0 {
+		t.Fatalf("bad: %#v", e)
+	}
+}
+
+func testContext(t *testing.T, opts *ContextOpts) *Context {
+	return NewContext(opts)
+}

terraform/graph.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/depgraph"
+	"github.com/hashicorp/terraform/helper/multierror"
 )
 
 // GraphOpts are options used to create the resource graph that Terraform
@@ -325,7 +326,7 @@ func graphAddMissingResourceProviders(
 	}
 
 	if len(errs) > 0 {
-		return &MultiError{Errors: errs}
+		return &multierror.Error{Errors: errs}
 	}
 
 	return nil
@@ -518,7 +519,7 @@ func graphInitResourceProviders(
 	}
 
 	if len(errs) > 0 {
-		return &MultiError{Errors: errs}
+		return &multierror.Error{Errors: errs}
 	}
 
 	return nil
@@ -583,7 +584,7 @@ func graphMapResourceProviders(g *depgraph.Graph) error {
 	}
 
 	if len(errs) > 0 {
-		return &MultiError{Errors: errs}
+		return &multierror.Error{Errors: errs}
 	}
 
 	return nil

terraform/multi_error.go

@@ -1,50 +0,0 @@
-package terraform
-
-import (
-	"fmt"
-	"strings"
-)
-
-// MultiError is an error type to track multiple errors. This is used to
-// accumulate errors in cases such as configuration parsing, and returning
-// them as a single error.
-type MultiError struct {
-	Errors []error
-}
-
-func (e *MultiError) Error() string {
-	points := make([]string, len(e.Errors))
-	for i, err := range e.Errors {
-		points[i] = fmt.Sprintf("* %s", err)
-	}
-
-	return fmt.Sprintf(
-		"%d error(s) occurred:\n\n%s",
-		len(e.Errors), strings.Join(points, "\n"))
-}
-
-// MultiErrorAppend is a helper function that will append more errors
-// onto a MultiError in order to create a larger multi-error. If the
-// original error is not a MultiError, it will be turned into one.
-func MultiErrorAppend(err error, errs ...error) *MultiError {
-	if err == nil {
-		err = new(MultiError)
-	}
-
-	switch err := err.(type) {
-	case *MultiError:
-		if err == nil {
-			err = new(MultiError)
-		}
-
-		err.Errors = append(err.Errors, errs...)
-		return err
-	default:
-		newErrs := make([]error, len(errs)+1)
-		newErrs[0] = err
-		copy(newErrs[1:], errs)
-		return &MultiError{
-			Errors: newErrs,
-		}
-	}
-}

terraform/multi_error_test.go

@@ -1,56 +0,0 @@
-package terraform
-
-import (
-	"errors"
-	"testing"
-)
-
-func TestMultiError_Impl(t *testing.T) {
-	var raw interface{}
-	raw = &MultiError{}
-	if _, ok := raw.(error); !ok {
-		t.Fatal("MultiError must implement error")
-	}
-}
-
-func TestMultiErrorError(t *testing.T) {
-	expected := `2 error(s) occurred:
-
-* foo
-* bar`
-
-	errors := []error{
-		errors.New("foo"),
-		errors.New("bar"),
-	}
-
-	multi := &MultiError{errors}
-	if multi.Error() != expected {
-		t.Fatalf("bad: %s", multi.Error())
-	}
-}
-
-func TestMultiErrorAppend_MultiError(t *testing.T) {
-	original := &MultiError{
-		Errors: []error{errors.New("foo")},
-	}
-
-	result := MultiErrorAppend(original, errors.New("bar"))
-	if len(result.Errors) != 2 {
-		t.Fatalf("wrong len: %d", len(result.Errors))
-	}
-
-	original = &MultiError{}
-	result = MultiErrorAppend(original, errors.New("bar"))
-	if len(result.Errors) != 1 {
-		t.Fatalf("wrong len: %d", len(result.Errors))
-	}
-}
-
-func TestMultiErrorAppend_NonMultiError(t *testing.T) {
-	original := errors.New("foo")
-	result := MultiErrorAppend(original, errors.New("bar"))
-	if len(result.Errors) != 2 {
-		t.Fatalf("wrong len: %d", len(result.Errors))
-	}
-}

terraform/terraform.go

@@ -8,6 +8,7 @@ import (
 
 	"github.com/hashicorp/terraform/config"
 	"github.com/hashicorp/terraform/depgraph"
+	"github.com/hashicorp/terraform/helper/multierror"
 )
 
 // Terraform is the primary structure that is used to interact with
@@ -282,7 +283,7 @@ func (t *Terraform) applyWalkFn(
 		// Determine the new state and update variables
 		err = nil
 		if len(errs) > 0 {
-			err = &MultiError{Errors: errs}
+			err = &multierror.Error{Errors: errs}
 		}
 
 		return r.Vars(), err

terraform/test-fixtures/validate-bad-var/main.tf

@@ -0,0 +1,7 @@
+resource "aws_instance" "foo" {
+    num = "2"
+}
+
+resource "aws_instance" "bar" {
+    foo = "${var.foo}"
+}

terraform/test-fixtures/validate-good/main.tf

@@ -0,0 +1,7 @@
+resource "aws_instance" "foo" {
+    num = "2"
+}
+
+resource "aws_instance" "bar" {
+    foo = "bar"
+}

terraform/test-fixtures/validate-required-var/main.tf

@@ -0,0 +1,5 @@
+variable "foo" {}
+
+resource "aws_instance" "web" {
+  ami = "${var.foo}"
+}