terraform: more eval stuff

terraform/eval.go

@@ -1,24 +1,5 @@
 package terraform
 
-import (
-	"github.com/hashicorp/terraform/config"
-)
-
-// EvalContext is the interface that is given to eval nodes to execute.
-type EvalContext interface {
-	// InitProvider initializes the provider with the given name and
-	// returns the implementation of the resource provider or an error.
-	InitProvider(string) (ResourceProvider, error)
-
-	// Provider gets the provider instance with the given name (already
-	// initialized) or returns nil if the provider isn't initialized.
-	Provider(string) ResourceProvider
-
-	// Interpolate takes the given raw configuration and completes
-	// the interpolations, returning the processed ResourceConfig.
-	Interpolate(*config.RawConfig) (*ResourceConfig, error)
-}
-
 // EvalNode is the interface that must be implemented by graph nodes to
 // evaluate/execute.
 type EvalNode interface {
@@ -41,40 +22,3 @@ type EvalNode interface {
 type GraphNodeEvalable interface {
 	EvalTree() EvalNode
 }
-
-// MockEvalContext is a mock version of EvalContext that can be used
-// for tests.
-type MockEvalContext struct {
-	InitProviderCalled   bool
-	InitProviderName     string
-	InitProviderProvider ResourceProvider
-	InitProviderError    error
-
-	ProviderCalled   bool
-	ProviderName     string
-	ProviderProvider ResourceProvider
-
-	InterpolateCalled       bool
-	InterpolateConfig       *config.RawConfig
-	InterpolateConfigResult *ResourceConfig
-	InterpolateError        error
-}
-
-func (c *MockEvalContext) InitProvider(n string) (ResourceProvider, error) {
-	c.InitProviderCalled = true
-	c.InitProviderName = n
-	return c.InitProviderProvider, c.InitProviderError
-}
-
-func (c *MockEvalContext) Provider(n string) ResourceProvider {
-	c.ProviderCalled = true
-	c.ProviderName = n
-	return c.ProviderProvider
-}
-
-func (c *MockEvalContext) Interpolate(
-	config *config.RawConfig) (*ResourceConfig, error) {
-	c.InterpolateCalled = true
-	c.InterpolateConfig = config
-	return c.InterpolateConfigResult, c.InterpolateError
-}

terraform/eval_context.go

@@ -0,0 +1,59 @@
+package terraform
+
+import (
+	"github.com/hashicorp/terraform/config"
+)
+
+// EvalContext is the interface that is given to eval nodes to execute.
+type EvalContext interface {
+	// InitProvider initializes the provider with the given name and
+	// returns the implementation of the resource provider or an error.
+	//
+	// It is an error to initialize the same provider more than once.
+	InitProvider(string) (ResourceProvider, error)
+
+	// Provider gets the provider instance with the given name (already
+	// initialized) or returns nil if the provider isn't initialized.
+	Provider(string) ResourceProvider
+
+	// Interpolate takes the given raw configuration and completes
+	// the interpolations, returning the processed ResourceConfig.
+	Interpolate(*config.RawConfig) (*ResourceConfig, error)
+}
+
+// MockEvalContext is a mock version of EvalContext that can be used
+// for tests.
+type MockEvalContext struct {
+	InitProviderCalled   bool
+	InitProviderName     string
+	InitProviderProvider ResourceProvider
+	InitProviderError    error
+
+	ProviderCalled   bool
+	ProviderName     string
+	ProviderProvider ResourceProvider
+
+	InterpolateCalled       bool
+	InterpolateConfig       *config.RawConfig
+	InterpolateConfigResult *ResourceConfig
+	InterpolateError        error
+}
+
+func (c *MockEvalContext) InitProvider(n string) (ResourceProvider, error) {
+	c.InitProviderCalled = true
+	c.InitProviderName = n
+	return c.InitProviderProvider, c.InitProviderError
+}
+
+func (c *MockEvalContext) Provider(n string) ResourceProvider {
+	c.ProviderCalled = true
+	c.ProviderName = n
+	return c.ProviderProvider
+}
+
+func (c *MockEvalContext) Interpolate(
+	config *config.RawConfig) (*ResourceConfig, error) {
+	c.InterpolateCalled = true
+	c.InterpolateConfig = config
+	return c.InterpolateConfigResult, c.InterpolateError
+}

terraform/eval_context_builtin.go

@@ -0,0 +1,55 @@
+package terraform
+
+import (
+	"fmt"
+	"sync"
+
+	"github.com/hashicorp/terraform/config"
+)
+
+// BuiltinEvalContext is an EvalContext implementation that is used by
+// Terraform by default.
+type BuiltinEvalContext struct {
+	Providers map[string]ResourceProviderFactory
+
+	providers map[string]ResourceProvider
+	once      sync.Once
+}
+
+func (ctx *BuiltinEvalContext) InitProvider(n string) (ResourceProvider, error) {
+	ctx.once.Do(ctx.init)
+
+	if p := ctx.Provider(n); p != nil {
+		return nil, fmt.Errorf("Provider '%s' already initialized", n)
+	}
+
+	f, ok := ctx.Providers[n]
+	if !ok {
+		return nil, fmt.Errorf("Provider '%s' not found", n)
+	}
+
+	return f()
+}
+
+func (ctx *BuiltinEvalContext) Provider(n string) ResourceProvider {
+	ctx.once.Do(ctx.init)
+	return ctx.providers[n]
+}
+
+func (ctx *BuiltinEvalContext) Interpolate(
+	config *config.RawConfig) (*ResourceConfig, error) {
+	// TODO: Actual interpolation, for now we just return it as-is
+	return NewResourceConfig(config), nil
+}
+
+func (ctx *BuiltinEvalContext) init() {
+	// We nil-check the things below because they're meant to be configured,
+	// and we just default them to non-nil.
+	if ctx.Providers == nil {
+		ctx.Providers = make(map[string]ResourceProviderFactory)
+	}
+
+	// We always reset the things below since we only call this once and
+	// they can't be initialized externally.
+	ctx.providers = make(map[string]ResourceProvider)
+}

terraform/eval_filter.go

@@ -0,0 +1,25 @@
+package terraform
+
+// EvalNodeFilterFunc is the callback used to replace a node with
+// another to node. To not do the replacement, just return the input node.
+type EvalNodeFilterFunc func(EvalNode) EvalNode
+
+// EvalNodeFilterable is an interface that can be implemented by
+// EvalNodes to allow filtering of sub-elements. Note that this isn't
+// a common thing to implement and you probably don't need it.
+type EvalNodeFilterable interface {
+	EvalNode
+	Filter(EvalNodeFilterFunc)
+}
+
+// EvalFilter runs the filter on the given node and returns the
+// final filtered value. This should be called rather than checking
+// the EvalNode directly since this will properly handle EvalNodeFilterables.
+func EvalFilter(node EvalNode, fn EvalNodeFilterFunc) EvalNode {
+	if f, ok := node.(EvalNodeFilterable); ok {
+		f.Filter(fn)
+		return node
+	}
+
+	return fn(node)
+}

terraform/eval_type.go

@@ -13,7 +13,7 @@ type EvalType uint32
 
 const (
 	EvalTypeInvalid          EvalType = 0
-	EvalTypeNull    EvalType = 1 << iota
+	EvalTypeNull             EvalType = 1 << iota // nil
-	EvalTypeConfig
+	EvalTypeConfig                                // *ResourceConfig
-	EvalTypeResourceProvider
+	EvalTypeResourceProvider                      // ResourceProvider
 )

terraform/transform_orphan.go

@@ -118,6 +118,22 @@ func (n *graphNodeOrphanResource) ProvidedBy() string {
 	return resourceProvider(n.ResourceName)
 }
 
+// GraphNodeEvalable impl.
+func (n *graphNodeOrphanResource) EvalTree() EvalNode {
+	return nil
+	/*
+		TODO
+			return &EvalSequence{
+				Nodes: []EvalNode{
+					&EvalRefresh{},
+					&EvalDiff{},
+					&EvalApply{},
+					&EvalCommitState{},
+				},
+			}
+	*/
+}
+
 func (n *graphNodeOrphanResource) dependableName() string {
 	return n.ResourceName
 }