terraform: OrphanResourceCountTransformer for orphaning extranneous

instances

terraform/node_resource_plan.go

@@ -29,6 +29,11 @@ func (n *NodePlannableResource) EvalTree() EvalNode {
 
 // GraphNodeDynamicExpandable
 func (n *NodePlannableResource) DynamicExpand(ctx EvalContext) (*Graph, error) {
+	// Grab the state which we read
+	state, lock := ctx.State()
+	lock.RLock()
+	defer lock.RUnlock()
+
 	// Expand the resource count which must be available by now from EvalTree
 	count, err := n.Config.Count()
 	if err != nil {
@@ -39,25 +44,45 @@ func (n *NodePlannableResource) DynamicExpand(ctx EvalContext) (*Graph, error) {
 	concreteResource := func(a *NodeAbstractResource) dag.Vertex {
 		// Add the config and state since we don't do that via transforms
 		a.Config = n.Config
-		a.ResourceState = n.ResourceState
 
 		return &NodePlannableResourceInstance{
 			NodeAbstractResource: a,
 		}
 	}
 
+	// The concrete resource factory we'll use for oprhans
+	concreteResourceOrphan := func(a *NodeAbstractResource) dag.Vertex {
+		return &NodePlannableResourceOrphan{
+			NodeAbstractResource: a,
+		}
+	}
+
 	// Start creating the steps
-	steps := make([]GraphTransformer, 0, 5)
+	steps := []GraphTransformer{
+		// Expand the count.
+		&ResourceCountTransformer{
+			Concrete: concreteResource,
+			Count:    count,
+			Addr:     n.ResourceAddr(),
+		},
 
-	// Expand counts.
-	steps = append(steps, &ResourceCountTransformer{
-		Concrete: concreteResource,
-		Count:    count,
-		Addr:     n.ResourceAddr(),
-	})
+		// Add the count orphans
+		&OrphanResourceCountTransformer{
+			Concrete: concreteResourceOrphan,
+			Count:    count,
+			Addr:     n.ResourceAddr(),
+			State:    state,
+		},
 
-	// Always end with the root being added
-	steps = append(steps, &RootTransformer{})
+		// TODO: deposed
+		// TODO: targeting
+
+		// Attach the state
+		&AttachStateTransformer{State: state},
+
+		// Make sure there is a single root
+		&RootTransformer{},
+	}
 
 	// Build the graph
 	b := &BasicGraphBuilder{Steps: steps, Validate: true}

terraform/transform_orphan_count.go

@@ -0,0 +1,99 @@
+package terraform
+
+import (
+	"log"
+
+	"github.com/hashicorp/terraform/dag"
+)
+
+// OrphanResourceCountTransformer is a GraphTransformer that adds orphans
+// for an expanded count to the graph. The determination of this depends
+// on the count argument given.
+//
+// Orphans are found by comparing the count to what is found in the state.
+// This tranform assumes that if an element in the state is within the count
+// bounds given, that it is not an orphan.
+type OrphanResourceCountTransformer struct {
+	Concrete ConcreteResourceNodeFunc
+
+	Count int              // Actual count of the resource
+	Addr  *ResourceAddress // Addr of the resource to look for orphans
+	State *State           // Full global state
+}
+
+func (t *OrphanResourceCountTransformer) Transform(g *Graph) error {
+	log.Printf("[TRACE] OrphanResourceCount: Starting...")
+
+	// Grab the module in the state just for this resource address
+	ms := t.State.ModuleByPath(normalizeModulePath(t.Addr.Path))
+	if ms == nil {
+		// If no state, there can't be orphans
+		return nil
+	}
+
+	// Go through the orphans and add them all to the state
+	for key, _ := range ms.Resources {
+		// Build the address
+		addr, err := parseResourceAddressInternal(key)
+		if err != nil {
+			return err
+		}
+		addr.Path = ms.Path[1:]
+
+		// Copy the address for comparison. If we aren't looking at
+		// the same resource, then just ignore it.
+		addrCopy := addr.Copy()
+		addrCopy.Index = -1
+		if !addrCopy.Equals(t.Addr) {
+			continue
+		}
+
+		log.Printf("[TRACE] OrphanResourceCount: Checking: %s", addr)
+
+		idx := addr.Index
+
+		// If we have zero and the index here is 0 or 1, then we
+		// change the index to a high number so that we treat it as
+		// an orphan.
+		if t.Count <= 0 && idx <= 0 {
+			idx = t.Count + 1
+		}
+
+		// If we have a count greater than 0 and we're at the zero index,
+		// we do a special case check to see if our state also has a
+		// -1 index value. If so, this is an orphan because our rules are
+		// that if both a -1 and 0 are in the state, the 0 is destroyed.
+		if t.Count > 0 && idx == -1 {
+			key := &ResourceStateKey{
+				Name:  addr.Name,
+				Type:  addr.Type,
+				Mode:  addr.Mode,
+				Index: 0,
+			}
+
+			if _, ok := ms.Resources[key.String()]; ok {
+				// We have a -1 index, too. Make an arbitrarily high
+				// index so that we always mark this as an orphan.
+				log.Printf("[WARN] OrphanResourceCount: %q both -1 and 0 index found, orphaning -1", addr)
+				idx = t.Count + 1
+			}
+		}
+
+		// If the index is within the count bounds, it is not an orphan
+		if idx < t.Count {
+			continue
+		}
+
+		// Build the abstract node and the concrete one
+		abstract := &NodeAbstractResource{Addr: addr}
+		var node dag.Vertex = abstract
+		if f := t.Concrete; f != nil {
+			node = f(abstract)
+		}
+
+		// Add it to the graph
+		g.Add(node)
+	}
+
+	return nil
+}

terraform/transform_orphan_count_test.go

@@ -0,0 +1,312 @@
+package terraform
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestOrphanResourceCountTransformer(t *testing.T) {
+	addr, err := parseResourceAddressInternal("aws_instance.foo")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: RootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.web": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.foo": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.foo.2": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	g := Graph{Path: RootModulePath}
+
+	{
+		tf := &OrphanResourceCountTransformer{
+			Concrete: testOrphanResourceConcreteFunc,
+			Count:    1,
+			Addr:     addr,
+			State:    state,
+		}
+		if err := tf.Transform(&g); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(testTransformOrphanResourceCountBasicStr)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
+func TestOrphanResourceCountTransformer_zero(t *testing.T) {
+	addr, err := parseResourceAddressInternal("aws_instance.foo")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: RootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.web": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.foo": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.foo.2": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	g := Graph{Path: RootModulePath}
+
+	{
+		tf := &OrphanResourceCountTransformer{
+			Concrete: testOrphanResourceConcreteFunc,
+			Count:    0,
+			Addr:     addr,
+			State:    state,
+		}
+		if err := tf.Transform(&g); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(testTransformOrphanResourceCountZeroStr)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
+func TestOrphanResourceCountTransformer_oneNoIndex(t *testing.T) {
+	addr, err := parseResourceAddressInternal("aws_instance.foo")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: RootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.web": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.foo": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.foo.2": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	g := Graph{Path: RootModulePath}
+
+	{
+		tf := &OrphanResourceCountTransformer{
+			Concrete: testOrphanResourceConcreteFunc,
+			Count:    1,
+			Addr:     addr,
+			State:    state,
+		}
+		if err := tf.Transform(&g); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(testTransformOrphanResourceCountOneNoIndexStr)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
+func TestOrphanResourceCountTransformer_oneIndex(t *testing.T) {
+	addr, err := parseResourceAddressInternal("aws_instance.foo")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: RootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.web": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.foo.0": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.foo.1": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	g := Graph{Path: RootModulePath}
+
+	{
+		tf := &OrphanResourceCountTransformer{
+			Concrete: testOrphanResourceConcreteFunc,
+			Count:    1,
+			Addr:     addr,
+			State:    state,
+		}
+		if err := tf.Transform(&g); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(testTransformOrphanResourceCountOneIndexStr)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
+func TestOrphanResourceCountTransformer_zeroAndNone(t *testing.T) {
+	addr, err := parseResourceAddressInternal("aws_instance.foo")
+	if err != nil {
+		t.Fatalf("err: %s", err)
+	}
+
+	state := &State{
+		Modules: []*ModuleState{
+			&ModuleState{
+				Path: RootModulePath,
+				Resources: map[string]*ResourceState{
+					"aws_instance.web": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.foo": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+
+					"aws_instance.foo.0": &ResourceState{
+						Type: "aws_instance",
+						Primary: &InstanceState{
+							ID: "foo",
+						},
+					},
+				},
+			},
+		},
+	}
+
+	g := Graph{Path: RootModulePath}
+
+	{
+		tf := &OrphanResourceCountTransformer{
+			Concrete: testOrphanResourceConcreteFunc,
+			Count:    1,
+			Addr:     addr,
+			State:    state,
+		}
+		if err := tf.Transform(&g); err != nil {
+			t.Fatalf("err: %s", err)
+		}
+	}
+
+	actual := strings.TrimSpace(g.String())
+	expected := strings.TrimSpace(testTransformOrphanResourceCountZeroAndNoneStr)
+	if actual != expected {
+		t.Fatalf("bad:\n\n%s", actual)
+	}
+}
+
+const testTransformOrphanResourceCountBasicStr = `
+aws_instance.foo[2] (orphan)
+`
+
+const testTransformOrphanResourceCountZeroStr = `
+aws_instance.foo (orphan)
+aws_instance.foo[2] (orphan)
+`
+
+const testTransformOrphanResourceCountOneNoIndexStr = `
+aws_instance.foo[2] (orphan)
+`
+
+const testTransformOrphanResourceCountOneIndexStr = `
+aws_instance.foo[1] (orphan)
+`
+
+const testTransformOrphanResourceCountZeroAndNoneStr = `
+aws_instance.foo (orphan)
+`