Merge pull request #36 from coreos/gc

api/database: Add the ability to delete layers

api/logic/layers.go

@@ -51,6 +51,18 @@ func POSTLayers(w http.ResponseWriter, r *http.Request, _ httprouter.Params) {
 	jsonhttp.Render(w, http.StatusCreated, struct{ Version string }{Version: strconv.Itoa(worker.Version)})
 }
 
+// DeleteLayer deletes the specified layer and any child layers that are
+// dependent on the specified layer.
+func DELETELayers(w http.ResponseWriter, r *http.Request, p httprouter.Params) {
+	err := database.DeleteLayer(p.ByName("id"))
+	if err != nil {
+		jsonhttp.RenderError(w, 0, err)
+		return
+	}
+
+	jsonhttp.Render(w, http.StatusNoContent, nil)
+}
+
 // GETLayersOS returns the operating system of a layer if it exists.
 // It uses not only the specified layer but also its parent layers if necessary.
 // An empty OS string is returned if no OS has been detected.

api/router.go

@@ -68,6 +68,7 @@ func NewRouterV1(to time.Duration) *httprouter.Router {
 
 	// Layers
 	router.POST("/layers", wrap(logic.POSTLayers))
+	router.DELETE("/layers/:id", wrap(logic.DELETELayers))
 	router.GET("/layers/:id/os", wrap(logic.GETLayersOS))
 	router.GET("/layers/:id/parent", wrap(logic.GETLayersParent))
 	router.GET("/layers/:id/packages", wrap(logic.GETLayersPackages))

database/layer.go

@@ -131,6 +131,60 @@ func InsertLayer(layer *Layer) error {
 	return nil
 }
 
+// DeleteLayer deletes the specified layer and any child layers that are
+// dependent on the specified layer.
+func DeleteLayer(ID string) error {
+	layer, err := FindOneLayerByID(ID, []string{})
+	if err != nil {
+		return err
+	}
+	return deleteLayerTreeFrom(layer.Node, nil)
+}
+
+func deleteLayerTreeFrom(node string, t *graph.Transaction) error {
+	// Determine if that function call is the root call of the recursivity
+	// And create transaction if its the case.
+	root := (t == nil)
+	if root {
+		t = cayley.NewTransaction()
+	}
+
+	// Find layer.
+	layer, err := FindOneLayerByNode(node, FieldLayerAll)
+	if err != nil {
+		// Ignore missing layer.
+		return nil
+	}
+
+	// Remove all successor layers.
+	for _, succNode := range layer.SuccessorsNodes {
+		deleteLayerTreeFrom(succNode, t)
+	}
+
+	// Remove layer.
+	t.RemoveQuad(cayley.Quad(layer.Node, FieldIs, FieldLayerIsValue, ""))
+	t.RemoveQuad(cayley.Quad(layer.Node, FieldLayerID, layer.ID, ""))
+	t.RemoveQuad(cayley.Quad(layer.Node, FieldLayerParent, layer.ParentNode, ""))
+	t.RemoveQuad(cayley.Quad(layer.Node, FieldLayerOS, layer.OS, ""))
+	t.RemoveQuad(cayley.Quad(layer.Node, FieldLayerEngineVersion, strconv.Itoa(layer.EngineVersion), ""))
+	for _, pkg := range layer.InstalledPackagesNodes {
+		t.RemoveQuad(cayley.Quad(layer.Node, FieldLayerInstalledPackages, pkg, ""))
+	}
+	for _, pkg := range layer.RemovedPackagesNodes {
+		t.RemoveQuad(cayley.Quad(layer.Node, FieldLayerRemovedPackages, pkg, ""))
+	}
+
+	// Apply transaction if root call.
+	if root {
+		if err = store.ApplyTransaction(t); err != nil {
+			log.Errorf("failed transaction (deleteLayerTreeFrom): %s", err)
+			return ErrTransaction
+		}
+	}
+
+	return nil
+}
+
 // FindOneLayerByID finds and returns a single layer having the given ID,
 // selecting the specified fields and hardcoding its ID
 func FindOneLayerByID(ID string, selectedFields []string) (*Layer, error) {

database/layer_test.go

@@ -18,6 +18,7 @@ import (
 	"testing"
 
 	"github.com/coreos/clair/utils"
+	cerrors "github.com/coreos/clair/utils/errors"
 	"github.com/stretchr/testify/assert"
 )
 
@@ -38,7 +39,7 @@ func TestLayerSimple(t *testing.T) {
 	// Insert a layer and find it back
 	l1 := &Layer{ID: "l1", OS: "os1", InstalledPackagesNodes: []string{"p1", "p2"}, EngineVersion: 1}
 	if assert.Nil(t, InsertLayer(l1)) {
-		fl1, err := FindOneLayerByID("l1", FieldLayerAll)
+		fl1, err := FindOneLayerByID(l1.ID, FieldLayerAll)
 		if assert.Nil(t, err) && assert.NotNil(t, fl1) {
 			// Saved = found
 			assert.True(t, layerEqual(l1, fl1), "layers are not equal, expected %v, have %s", l1, fl1)
@@ -66,6 +67,12 @@ func TestLayerSimple(t *testing.T) {
 		if assert.Nil(t, err) && assert.Len(t, al1, 1) {
 			assert.Equal(t, al1[0].Node, l1.Node)
 		}
+
+		// Delete
+		if assert.Nil(t, DeleteLayer(l1.ID)) {
+			_, err := FindOneLayerByID(l1.ID, FieldLayerAll)
+			assert.Equal(t, cerrors.ErrNotFound, err)
+		}
 	}
 }
 
@@ -119,6 +126,14 @@ func TestLayerTree(t *testing.T) {
 		fl4bpkg, err := flayers[4].AllPackages()
 		assert.Nil(t, err)
 		assert.Len(t, fl4bpkg, 0)
+
+		// Delete a layer in the middle of the tree.
+		if assert.Nil(t, DeleteLayer(flayers[1].ID)) {
+			for _, l := range layers[1:] {
+				_, err := FindOneLayerByID(l.ID, FieldLayerAll)
+				assert.Equal(t, cerrors.ErrNotFound, err)
+			}
+		}
 	}
 }
 

docs/API.md

@@ -150,6 +150,41 @@ HTTP/1.1 400 Bad Request
 
 It could also return a `415 Unsupported Media Type` response with a `Message` if the request content is not valid JSON.
 
+## Delete a Layer
+
+It deletes a layer from the database and any child layers that are dependent on the specified layer.
+
+	DELETE /v1/layers/{ID}
+
+### Parameters
+
+|Name|Type|Description|
+|------|-----|-------------|
+|ID|String|Unique ID of the Layer|
+
+### Example
+
+```
+curl -s -X DELETE 127.0.0.1:6060/v1/layers/39bb80489af75406073b5364c9c326134015140e1f7976a370a8bd446889e6f8
+```
+
+### Success Response
+
+```
+HTTP/1.1 204 No Content
+```
+
+### Error Response
+
+```
+HTTP/1.1 404 Not Found
+{
+    "Message": "the resource cannot be found"
+}
+```
+
+//////////
+
 ## Get a Layer's operating system
 
 It returns the operating system a given Layer.
@@ -210,6 +245,7 @@ HTTP/1.1 200 OK
 ```
 
 ### Error Response
+
 ```
 HTTP/1.1 404 Not Found
 {