terraform: module inputs are passed through to subgraphs

terraform/context.go

@@ -118,6 +118,9 @@ func (c *Context2) Plan(opts *PlanOpts) (*Plan, error) {
 
 	// Do the walk
 	walker, err := c.walk(operation)
+	if err != nil {
+		return nil, err
+	}
 	p.Diff = walker.Diff
 
 	// Update the diff so that our context is up-to-date

terraform/context_test.go

@@ -109,12 +109,11 @@ func TestContext2Plan_modules(t *testing.T) {
 	}
 }
 
-/*
-func TestContextPlan_moduleInput(t *testing.T) {
+func TestContext2Plan_moduleInput(t *testing.T) {
 	m := testModule(t, "plan-module-input")
 	p := testProvider("aws")
 	p.DiffFn = testDiffFn
-	ctx := testContext(t, &ContextOpts{
+	ctx := testContext2(t, &ContextOpts{
 		Module: m,
 		Providers: map[string]ResourceProviderFactory{
 			"aws": testProviderFuncFixed(p),
@@ -133,6 +132,7 @@ func TestContextPlan_moduleInput(t *testing.T) {
 	}
 }
 
+/*
 func TestContextPlan_moduleInputComputed(t *testing.T) {
 	m := testModule(t, "plan-module-input-computed")
 	p := testProvider("aws")

terraform/eval_context.go

@@ -49,6 +49,11 @@ type EvalContext interface {
 	// that is currently being acted upon.
 	Interpolate(*config.RawConfig, *Resource) (*ResourceConfig, error)
 
+	// SetVariables sets the variables for interpolation. These variables
+	// should not have a "var." prefix. For example: "var.foo" should be
+	// "foo" as the key.
+	SetVariables(map[string]string)
+
 	// Diff returns the global diff as well as the lock that should
 	// be used to modify that diff.
 	Diff() (*Diff, *sync.RWMutex)
@@ -100,6 +105,9 @@ type MockEvalContext struct {
 	PathCalled bool
 	PathPath   []string
 
+	SetVariablesCalled    bool
+	SetVariablesVariables map[string]string
+
 	DiffCalled bool
 	DiffDiff   *Diff
 	DiffLock   *sync.RWMutex
@@ -164,6 +172,11 @@ func (c *MockEvalContext) Path() []string {
 	return c.PathPath
 }
 
+func (c *MockEvalContext) SetVariables(vs map[string]string) {
+	c.SetVariablesCalled = true
+	c.SetVariablesVariables = vs
+}
+
 func (c *MockEvalContext) Diff() (*Diff, *sync.RWMutex) {
 	c.DiffCalled = true
 	return c.DiffDiff, c.DiffLock

terraform/eval_context_builtin.go

@@ -1,8 +1,6 @@
 package terraform
 
 import (
-	"crypto/md5"
-	"encoding/hex"
 	"fmt"
 	"sync"
 
@@ -72,7 +70,7 @@ func (ctx *BuiltinEvalContext) InitProvider(n string) (ResourceProvider, error)
 		return nil, err
 	}
 
-	ctx.ProviderCache[ctx.pathCacheKey(ctx.Path())] = p
+	ctx.ProviderCache[PathCacheKey(ctx.Path())] = p
 	return p, nil
 }
 
@@ -82,7 +80,7 @@ func (ctx *BuiltinEvalContext) Provider(n string) ResourceProvider {
 	ctx.ProviderLock.Lock()
 	defer ctx.ProviderLock.Unlock()
 
-	return ctx.ProviderCache[ctx.pathCacheKey(ctx.Path())]
+	return ctx.ProviderCache[PathCacheKey(ctx.Path())]
 }
 
 func (ctx *BuiltinEvalContext) ConfigureProvider(
@@ -94,7 +92,7 @@ func (ctx *BuiltinEvalContext) ConfigureProvider(
 
 	// Save the configuration
 	ctx.ProviderLock.Lock()
-	ctx.ProviderConfigCache[ctx.pathCacheKey(ctx.Path())] = cfg
+	ctx.ProviderConfigCache[PathCacheKey(ctx.Path())] = cfg
 	ctx.ProviderLock.Unlock()
 
 	return p.Configure(cfg)
@@ -106,7 +104,7 @@ func (ctx *BuiltinEvalContext) ParentProviderConfig(n string) *ResourceConfig {
 
 	path := ctx.Path()
 	for i := len(path) - 1; i >= 1; i-- {
-		k := ctx.pathCacheKey(path[:i])
+		k := PathCacheKey(path[:i])
 		if v, ok := ctx.ProviderConfigCache[k]; ok {
 			return v
 		}
@@ -139,7 +137,7 @@ func (ctx *BuiltinEvalContext) InitProvisioner(
 		return nil, err
 	}
 
-	ctx.ProvisionerCache[ctx.pathCacheKey(ctx.Path())] = p
+	ctx.ProvisionerCache[PathCacheKey(ctx.Path())] = p
 	return p, nil
 }
 
@@ -149,7 +147,7 @@ func (ctx *BuiltinEvalContext) Provisioner(n string) ResourceProvisioner {
 	ctx.ProvisionerLock.Lock()
 	defer ctx.ProvisionerLock.Unlock()
 
-	return ctx.ProvisionerCache[ctx.pathCacheKey(ctx.Path())]
+	return ctx.ProvisionerCache[PathCacheKey(ctx.Path())]
 }
 
 func (ctx *BuiltinEvalContext) Interpolate(
@@ -179,6 +177,12 @@ func (ctx *BuiltinEvalContext) Path() []string {
 	return ctx.PathValue
 }
 
+func (ctx *BuiltinEvalContext) SetVariables(vs map[string]string) {
+	for k, v := range vs {
+		ctx.Interpolater.Variables[k] = v
+	}
+}
+
 func (ctx *BuiltinEvalContext) Diff() (*Diff, *sync.RWMutex) {
 	return ctx.DiffValue, ctx.DiffLock
 }
@@ -194,23 +198,3 @@ func (ctx *BuiltinEvalContext) init() {
 		ctx.Providers = make(map[string]ResourceProviderFactory)
 	}
 }
-
-// pathCacheKey returns a cache key for the current module path, unique to
-// the module path.
-//
-// This is used because there is a variety of information that needs to be
-// cached per-path, rather than per-context.
-func (ctx *BuiltinEvalContext) pathCacheKey(path []string) string {
-	// There is probably a better way to do this, but this is working for now.
-	// We just create an MD5 hash of all the MD5 hashes of all the path
-	// elements. This gets us the property that it is unique per ordering.
-	hash := md5.New()
-	for _, p := range path {
-		single := md5.Sum([]byte(p))
-		if _, err := hash.Write(single[:]); err != nil {
-			panic(err)
-		}
-	}
-
-	return hex.EncodeToString(hash.Sum(nil))
-}

terraform/eval_variable.go

@@ -0,0 +1,64 @@
+package terraform
+
+import (
+	"github.com/hashicorp/terraform/config"
+)
+
+// EvalSetVariables is an EvalNode implementation that sets the variables
+// explicitly for interpolation later.
+type EvalSetVariables struct {
+	Variables map[string]string
+}
+
+func (n *EvalSetVariables) Args() ([]EvalNode, []EvalType) {
+	return nil, nil
+}
+
+// TODO: test
+func (n *EvalSetVariables) Eval(
+	ctx EvalContext, args []interface{}) (interface{}, error) {
+	ctx.SetVariables(n.Variables)
+	return nil, nil
+}
+
+func (n *EvalSetVariables) Type() EvalType {
+	return EvalTypeNull
+}
+
+// EvalVariableBlock is an EvalNode implementation that evaluates the
+// given configuration, and uses the final values as a way to set the
+// mapping.
+type EvalVariableBlock struct {
+	Config    EvalNode
+	Variables map[string]string
+}
+
+func (n *EvalVariableBlock) Args() ([]EvalNode, []EvalType) {
+	return []EvalNode{n.Config}, []EvalType{EvalTypeConfig}
+}
+
+// TODO: test
+func (n *EvalVariableBlock) Eval(
+	ctx EvalContext, args []interface{}) (interface{}, error) {
+	// Clear out the existing mapping
+	for k, _ := range n.Variables {
+		delete(n.Variables, k)
+	}
+
+	// Get our configuration
+	rc := args[0].(*ResourceConfig)
+	for k, v := range rc.Config {
+		n.Variables[k] = v.(string)
+	}
+	for k, _ := range rc.Raw {
+		if _, ok := n.Variables[k]; !ok {
+			n.Variables[k] = config.UnknownVariableValue
+		}
+	}
+
+	return nil, nil
+}
+
+func (n *EvalVariableBlock) Type() EvalType {
+	return EvalTypeNull
+}

terraform/graph_config_node.go

@@ -48,8 +48,26 @@ func (n *GraphNodeConfigModule) Name() string {
 }
 
 // GraphNodeExpandable
-func (n *GraphNodeConfigModule) Expand(b GraphBuilder) (*Graph, error) {
-	return b.Build(n.Path)
+func (n *GraphNodeConfigModule) Expand(b GraphBuilder) (GraphNodeSubgraph, error) {
+	// Build the graph first
+	graph, err := b.Build(n.Path)
+	if err != nil {
+		return nil, err
+	}
+
+	// Add the parameters node to the module
+	t := &ModuleInputTransformer{Variables: make(map[string]string)}
+	if err := t.Transform(graph); err != nil {
+		return nil, err
+	}
+
+	// Build the actual subgraph node
+	return &graphNodeModuleExpanded{
+		Original:    n,
+		Graph:       graph,
+		InputConfig: n.Module.RawConfig,
+		Variables:   t.Variables,
+	}, nil
 }
 
 // GraphNodeExpandable
@@ -181,3 +199,34 @@ func (n *GraphNodeConfigResource) ProvisionedBy() []string {
 
 	return result
 }
+
+// graphNodeModuleExpanded represents a module where the graph has
+// been expanded. It stores the graph of the module as well as a reference
+// to the map of variables.
+type graphNodeModuleExpanded struct {
+	Original    dag.Vertex
+	Graph       *Graph
+	InputConfig *config.RawConfig
+
+	// Variables is a map of the input variables. This reference should
+	// be shared with ModuleInputTransformer in order to create a connection
+	// where the variables are set properly.
+	Variables map[string]string
+}
+
+func (n *graphNodeModuleExpanded) Name() string {
+	return fmt.Sprintf("%s (expanded)", dag.VertexName(n.Original))
+}
+
+// GraphNodeEvalable impl.
+func (n *graphNodeModuleExpanded) EvalTree() EvalNode {
+	return &EvalVariableBlock{
+		Config:    &EvalInterpolate{Config: n.InputConfig},
+		Variables: n.Variables,
+	}
+}
+
+// GraphNodeSubgraph impl.
+func (n *graphNodeModuleExpanded) Subgraph() *Graph {
+	return n.Graph
+}

terraform/graph_config_node_test.go

@@ -34,7 +34,7 @@ func TestGraphNodeConfigModuleExpand(t *testing.T) {
 		t.Fatalf("err: %s", err)
 	}
 
-	actual := strings.TrimSpace(g.String())
+	actual := strings.TrimSpace(g.Subgraph().String())
 	expected := strings.TrimSpace(testGraphNodeModuleExpandStr)
 	if actual != expected {
 		t.Fatalf("bad:\n\n%s", actual)

terraform/graph_walk_context.go

@@ -26,6 +26,8 @@ type ContextGraphWalker struct {
 	errorLock           sync.Mutex
 	once                sync.Once
 	diffLock            sync.RWMutex
+	contexts            map[string]*BuiltinEvalContext
+	contextLock         sync.Mutex
 	providerCache       map[string]ResourceProvider
 	providerConfigCache map[string]*ResourceConfig
 	providerLock        sync.Mutex
@@ -36,7 +38,25 @@ type ContextGraphWalker struct {
 func (w *ContextGraphWalker) EnterGraph(g *Graph) EvalContext {
 	w.once.Do(w.init)
 
-	return &BuiltinEvalContext{
+	w.contextLock.Lock()
+	defer w.contextLock.Unlock()
+
+	// If we already have a context for this path cached, use that
+	key := PathCacheKey(g.Path)
+	if ctx, ok := w.contexts[key]; ok {
+		return ctx
+	}
+
+	// Variables should be our context variables, but these only apply
+	// to the root module. As we enter subgraphs, we don't want to set
+	// variables, which is set by the SetVariables EvalContext function.
+	variables := w.Context.variables
+	if len(g.Path) > 1 {
+		// We're in a submodule, the variables should be empty
+		variables = make(map[string]string)
+	}
+
+	ctx := &BuiltinEvalContext{
 		PathValue:           g.Path,
 		Hooks:               w.Context.hooks,
 		Providers:           w.Context.providers,
@@ -55,9 +75,12 @@ func (w *ContextGraphWalker) EnterGraph(g *Graph) EvalContext {
 			Module:    w.Context.module,
 			State:     w.Context.state,
 			StateLock: &w.Context.stateLock,
-			Variables: w.Context.variables,
+			Variables: variables,
 		},
 	}
+
+	w.contexts[key] = ctx
+	return ctx
 }
 
 func (w *ContextGraphWalker) EnterEvalTree(v dag.Vertex, n EvalNode) EvalNode {
@@ -94,6 +117,7 @@ func (w *ContextGraphWalker) init() {
 	w.Diff = new(Diff)
 	w.Diff.init()
 
+	w.contexts = make(map[string]*BuiltinEvalContext, 5)
 	w.providerCache = make(map[string]ResourceProvider, 5)
 	w.providerConfigCache = make(map[string]*ResourceConfig, 5)
 	w.provisionerCache = make(map[string]ResourceProvisioner, 5)

terraform/path.go

@@ -0,0 +1,24 @@
+package terraform
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+)
+
+// PathCacheKey returns a cache key for a module path.
+//
+// TODO: test
+func PathCacheKey(path []string) string {
+	// There is probably a better way to do this, but this is working for now.
+	// We just create an MD5 hash of all the MD5 hashes of all the path
+	// elements. This gets us the property that it is unique per ordering.
+	hash := md5.New()
+	for _, p := range path {
+		single := md5.Sum([]byte(p))
+		if _, err := hash.Write(single[:]); err != nil {
+			panic(err)
+		}
+	}
+
+	return hex.EncodeToString(hash.Sum(nil))
+}

terraform/transform_expand.go

@@ -1,8 +1,6 @@
 package terraform
 
 import (
-	"fmt"
-
 	"github.com/hashicorp/terraform/dag"
 )
 
@@ -10,7 +8,7 @@ import (
 // signal that they can be expanded. Expanded nodes turn into
 // GraphNodeSubgraph nodes within the graph.
 type GraphNodeExpandable interface {
-	Expand(GraphBuilder) (*Graph, error)
+	Expand(GraphBuilder) (GraphNodeSubgraph, error)
 }
 
 // GraphNodeDynamicExpandable is an interface that nodes can implement
@@ -43,27 +41,5 @@ func (t *ExpandTransform) Transform(v dag.Vertex) (dag.Vertex, error) {
 	}
 
 	// Expand the subgraph!
-	g, err := ev.Expand(t.Builder)
-	if err != nil {
-		return nil, err
-	}
-
-	// Replace with our special node
-	return &graphNodeExpanded{
-		Graph:        g,
-		OriginalName: dag.VertexName(v),
-	}, nil
-}
-
-type graphNodeExpanded struct {
-	Graph        *Graph
-	OriginalName string
-}
-
-func (n *graphNodeExpanded) Name() string {
-	return fmt.Sprintf("%s (expanded)", n.OriginalName)
-}
-
-func (n *graphNodeExpanded) Subgraph() *Graph {
-	return n.Graph
+	return ev.Expand(t.Builder)
 }

terraform/transform_module.go

@@ -0,0 +1,47 @@
+package terraform
+
+import (
+	"github.com/hashicorp/terraform/dag"
+)
+
+// ModuleInputTransformer is a GraphTransformer that adds a node to the
+// graph for setting the module input variables for the remainder of the
+// graph.
+type ModuleInputTransformer struct {
+	Variables map[string]string
+}
+
+func (t *ModuleInputTransformer) Transform(g *Graph) error {
+	// Create the node
+	n := &graphNodeModuleInput{Variables: t.Variables}
+
+	// Add it to the graph
+	g.Add(n)
+
+	// Connect the inputs to the bottom of the graph so that it happens
+	// first.
+	for _, v := range g.Vertices() {
+		if v == n {
+			continue
+		}
+
+		if g.DownEdges(v).Len() == 0 {
+			g.Connect(dag.BasicEdge(v, n))
+		}
+	}
+
+	return nil
+}
+
+type graphNodeModuleInput struct {
+	Variables map[string]string
+}
+
+func (n *graphNodeModuleInput) Name() string {
+	return "module inputs"
+}
+
+// GraphNodeEvalable impl.
+func (n *graphNodeModuleInput) EvalTree() EvalNode {
+	return &EvalSetVariables{Variables: n.Variables}
+}

terraform/transform_module_test.go

@@ -0,0 +1,41 @@
+package terraform
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/hashicorp/terraform/dag"
+)
+
+func TestModuleInputTransformer(t *testing.T) {
+	var g Graph
+	g.Add(1)
+	g.Add(2)
+	g.Add(3)
+	g.Connect(dag.BasicEdge(1, 2))
+	g.Connect(dag.BasicEdge(1, 3))
+
+	{
+		tf := &ModuleInputTransformer{}
+		if err := tf.Transform(&g); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(testModuleInputTransformStr)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
+const testModuleInputTransformStr = `
+1
+  2
+  3
+2
+  module inputs
+3
+  module inputs
+module inputs
+`