Use resource.Resource throughout

Before we had an interface representing resources, they were generally
passed around as a pair of (id string, definition []byte). We can cut
down on the number of representations of resources by just using
`resource.Resource`.

This includes returning synchronisation errors with the whole
resource, rather than simply by name. Doing so means we will be able
to better surface sync problems with individual resources.

cluster/kubernetes/kubernetes.go

@@ -23,6 +23,7 @@ import (
 	"github.com/weaveworks/flux/cluster"
 	"github.com/weaveworks/flux/image"
 	"github.com/weaveworks/flux/registry"
+	"github.com/weaveworks/flux/resource"
 	"github.com/weaveworks/flux/ssh"
 )
 
@@ -40,15 +41,23 @@ type extendedClient struct {
 	v1beta1batch.CronJobsGetter
 }
 
+// --- internal types for keeping track of syncing
+
 type apiObject struct {
-	bytes    []byte
+	resource.Resource
 	Kind     string `yaml:"kind"`
 	Metadata struct {
 		Name      string `yaml:"name"`
 		Namespace string `yaml:"namespace"`
 	} `yaml:"metadata"`
 }
 
+// A convenience for getting an minimal object from some bytes.
+func parseObj(def []byte) (*apiObject, error) {
+	obj := apiObject{}
+	return &obj, yaml.Unmarshal(def, &obj)
+}
+
 func (o *apiObject) hasNamespace() bool {
 	return o.Metadata.Namespace != ""
 }
@@ -85,32 +94,27 @@ func isAddon(obj namespacedLabeled) bool {
 // --- /add ons
 
 type changeSet struct {
-	nsObjs   map[string][]obj
-	noNsObjs map[string][]obj
+	nsObjs   map[string][]*apiObject
+	noNsObjs map[string][]*apiObject
 }
 
 func makeChangeSet() changeSet {
 	return changeSet{
-		nsObjs:   make(map[string][]obj),
-		noNsObjs: make(map[string][]obj),
+		nsObjs:   make(map[string][]*apiObject),
+		noNsObjs: make(map[string][]*apiObject),
 	}
 }
 
-func (c *changeSet) stage(cmd, id string, o *apiObject) {
+func (c *changeSet) stage(cmd string, o *apiObject) {
 	if o.hasNamespace() {
-		c.nsObjs[cmd] = append(c.nsObjs[cmd], obj{id, o})
+		c.nsObjs[cmd] = append(c.nsObjs[cmd], o)
 	} else {
-		c.noNsObjs[cmd] = append(c.noNsObjs[cmd], obj{id, o})
+		c.noNsObjs[cmd] = append(c.noNsObjs[cmd], o)
 	}
 }
 
-type obj struct {
-	id string
-	*apiObject
-}
-
 type Applier interface {
-	apply(log.Logger, changeSet, cluster.SyncError)
+	apply(log.Logger, changeSet) cluster.SyncErrors
 }
 
 // Cluster is a handle to a Kubernetes API server.
@@ -217,34 +221,38 @@ func (c *Cluster) Sync(spec cluster.SyncDef) error {
 	logger := log.With(c.logger, "method", "Sync")
 
 	cs := makeChangeSet()
-	errs := cluster.SyncError{}
+	var errs cluster.SyncErrors
 	for _, action := range spec.Actions {
 		stages := []struct {
-			b   []byte
+			res resource.Resource
 			cmd string
 		}{
 			{action.Delete, "delete"},
 			{action.Apply, "apply"},
 		}
 		for _, stage := range stages {
-			if len(stage.b) == 0 {
+			if stage.res == nil {
 				continue
 			}
-			obj, err := definitionObj(stage.b)
-			id := action.ResourceID
+			obj, err := parseObj(stage.res.Bytes())
 			if err == nil {
-				cs.stage(stage.cmd, id, obj)
+				obj.Resource = stage.res
+				cs.stage(stage.cmd, obj)
 			} else {
-				errs[id] = err
+				errs = append(errs, cluster.SyncError{Resource: stage.res, Error: err})
 				break
 			}
 		}
 	}
 
 	c.mu.Lock()
 	defer c.mu.Unlock()
-	c.applier.apply(logger, cs, errs)
-	if len(errs) != 0 {
+	if applyErrs := c.applier.apply(logger, cs); len(applyErrs) > 0 {
+		errs = append(errs, applyErrs...)
+	}
+
+	// If `nil`, errs is a cluster.SyncError(nil) rather than error(nil)
+	if errs != nil {
 		return errs
 	}
 	return nil
@@ -408,11 +416,3 @@ func (c *Cluster) ImagesToFetch() registry.ImageCreds {
 
 	return allImageCreds
 }
-
-// --- end cluster.Cluster
-
-// A convenience for getting an minimal object from some bytes.
-func definitionObj(bytes []byte) (*apiObject, error) {
-	obj := apiObject{bytes: bytes}
-	return &obj, yaml.Unmarshal(bytes, &obj)
-}

cluster/kubernetes/kubernetes_test.go

@@ -5,24 +5,41 @@ import (
 
 	"github.com/go-kit/kit/log"
 
+	"github.com/weaveworks/flux"
 	"github.com/weaveworks/flux/cluster"
+	"github.com/weaveworks/flux/policy"
 )
 
 type mockApplier struct {
 	commandRun bool
 }
 
-func (m *mockApplier) apply(_ log.Logger, c changeSet, _ cluster.SyncError) {
+func (m *mockApplier) apply(_ log.Logger, c changeSet) cluster.SyncErrors {
 	if len(c.nsObjs) != 0 || len(c.noNsObjs) != 0 {
 		m.commandRun = true
 	}
+	return nil
 }
 
-func deploymentDef(name string) []byte {
-	return []byte(`---
-kind: Deployment
-metadata:
-  name: ` + name)
+type rsc struct {
+	id    string
+	bytes []byte
+}
+
+func (r rsc) ResourceID() flux.ResourceID {
+	return flux.MustParseResourceID(r.id)
+}
+
+func (r rsc) Bytes() []byte {
+	return r.bytes
+}
+
+func (r rsc) Policy() policy.Set {
+	return nil
+}
+
+func (r rsc) Source() string {
+	return "test"
 }
 
 // ---
@@ -39,7 +56,7 @@ func setup(t *testing.T) (*Cluster, *mockApplier) {
 func TestSyncNop(t *testing.T) {
 	kube, mock := setup(t)
 	if err := kube.Sync(cluster.SyncDef{}); err != nil {
-		t.Error(err)
+		t.Errorf("%#v", err)
 	}
 	if mock.commandRun {
 		t.Error("expected no commands run")
@@ -51,8 +68,7 @@ func TestSyncMalformed(t *testing.T) {
 	err := kube.Sync(cluster.SyncDef{
 		Actions: []cluster.SyncAction{
 			cluster.SyncAction{
-				ResourceID: "foobar",
-				Apply:      []byte("garbage"),
+				Apply: rsc{"id", []byte("garbage")},
 			},
 		},
 	})

cluster/kubernetes/release.go

@@ -52,8 +52,8 @@ func (c *Kubectl) connectArgs() []string {
 	return args
 }
 
-func (c *Kubectl) apply(logger log.Logger, cs changeSet, errs cluster.SyncError) {
-	f := func(m map[string][]obj, cmd string, args ...string) {
+func (c *Kubectl) apply(logger log.Logger, cs changeSet) (errs cluster.SyncErrors) {
+	f := func(m map[string][]*apiObject, cmd string, args ...string) {
 		objs := m[cmd]
 		if len(objs) == 0 {
 			return
@@ -62,9 +62,9 @@ func (c *Kubectl) apply(logger log.Logger, cs changeSet, errs cluster.SyncError)
 		args = append(args, cmd)
 		if err := c.doCommand(logger, makeMultidoc(objs), args...); err != nil {
 			for _, obj := range objs {
-				r := bytes.NewReader(obj.bytes)
+				r := bytes.NewReader(obj.Bytes())
 				if err := c.doCommand(logger, r, args...); err != nil {
-					errs[obj.id] = err
+					errs = append(errs, cluster.SyncError{obj.Resource, err})
 				}
 			}
 		}
@@ -79,7 +79,7 @@ func (c *Kubectl) apply(logger log.Logger, cs changeSet, errs cluster.SyncError)
 	// first, so we run the commands the other way round.
 	f(cs.noNsObjs, "apply", "--namespace", "default")
 	f(cs.nsObjs, "apply")
-
+	return errs
 }
 
 func (c *Kubectl) doCommand(logger log.Logger, r io.Reader, args ...string) error {
@@ -101,10 +101,11 @@ func (c *Kubectl) doCommand(logger log.Logger, r io.Reader, args ...string) erro
 	return err
 }
 
-func makeMultidoc(objs []obj) *bytes.Buffer {
+func makeMultidoc(objs []*apiObject) *bytes.Buffer {
 	buf := &bytes.Buffer{}
 	for _, obj := range objs {
-		buf.WriteString("\n---\n" + string(obj.bytes))
+		buf.WriteString("\n---\n")
+		buf.Write(obj.Bytes())
 	}
 	return buf
 }

cluster/kubernetes/update.go

@@ -20,7 +20,7 @@ import (
 // the source to learn about them.
 func updatePodController(def []byte, container string, newImageID image.Ref) ([]byte, error) {
 	// Sanity check
-	obj, err := definitionObj(def)
+	obj, err := parseObj(def)
 	if err != nil {
 		return nil, err
 	}

cluster/sync.go

@@ -2,37 +2,35 @@ package cluster
 
 import (
 	"strings"
+
+	"github.com/weaveworks/flux/resource"
 )
 
 // Definitions for use in synchronising a cluster with a git repo.
 
-// Yep, resources are defined by opaque bytes. It's up to the cluster
-// at the other end to do the right thing.
-type ResourceDef []byte
-
-// The action(s) to take on a particular resource.
-// This should just be done in order, i.e.,:
-//  1. delete if something in Delete
-//  2. apply if something in Apply
+// SyncAction represents either the deletion or application (create or
+// update) of a resource.
 type SyncAction struct {
-	// The ID is just a handle for labeling any error. No other
-	// meaning is attached to it.
-	ResourceID string
-	Delete     ResourceDef
-	Apply      ResourceDef
+	Delete     resource.Resource // ) one of these
+	Apply      resource.Resource // )
 }
 
 type SyncDef struct {
 	// The actions to undertake
 	Actions []SyncAction
 }
 
-type SyncError map[string]error
+type SyncError struct {
+	resource.Resource
+	Error error
+}
+
+type SyncErrors []SyncError
 
-func (err SyncError) Error() string {
+func (err SyncErrors) Error() string {
 	var errs []string
-	for id, e := range err {
-		errs = append(errs, id+": "+e.Error())
+	for _, e := range err {
+		errs = append(errs, e.ResourceID().String()+": "+e.Error.Error())
 	}
 	return strings.Join(errs, "; ")
 }

sync/sync.go

@@ -55,8 +55,7 @@ func prepareSyncDelete(logger log.Logger, repoResources map[string]resource.Reso
 	}
 	if _, ok := repoResources[id]; !ok {
 		sync.Actions = append(sync.Actions, cluster.SyncAction{
-			ResourceID: id,
-			Delete:     res.Bytes(),
+			Delete:     res,
 		})
 	}
 }
@@ -73,7 +72,6 @@ func prepareSyncApply(logger log.Logger, clusterResources map[string]resource.Re
 		}
 	}
 	sync.Actions = append(sync.Actions, cluster.SyncAction{
-		ResourceID: id,
-		Apply:      res.Bytes(),
+		Apply:      res,
 	})
 }