feat(kubernetes): sort objects (#244)

* Sort kubernetes objects before applying.

Instead of just applying namespces before everything else, let's sort
all the objects. There's more inter-dependences between various kinds,
e.g. CRDs need to be applied before the actual custom resources,
StorageClasses before the PVCs, ... .

Signed-off-by: Milan Plzik <milan.plzik@grafana.com>

* Move object sorting to the Reconcile phase.

As suggested in
#244 (comment) ,
`Reconcile()` might be a better place for sorting, since we're already
doing sort-of (pun intended) similar thing there.

Signed-off-by: Milan Plzik <milan.plzik@grafana.com>

* Fix review comments.

Signed-off-by: Milan Plzik <milan.plzik@grafana.com>

pkg/kubernetes/client/apply.go

@@ -4,25 +4,11 @@ import (
 	"os"
 	"strings"
 
-	funk "github.com/thoas/go-funk"
-
 	"github.com/grafana/tanka/pkg/kubernetes/manifest"
 )
 
 // Apply applies the given yaml to the cluster
 func (k Kubectl) Apply(data manifest.List, opts ApplyOpts) error {
-	// create namespaces first to succeed first try
-	ns := filterNamespace(data)
-	if len(ns) > 0 {
-		if err := k.apply(ns, opts); err != nil {
-			return err
-		}
-	}
-
-	return k.apply(data, opts)
-}
-
-func (k Kubectl) apply(data manifest.List, opts ApplyOpts) error {
 	argv := []string{"-f", "-"}
 	if opts.Force {
 		argv = append(argv, "--force")
@@ -40,9 +26,3 @@ func (k Kubectl) apply(data manifest.List, opts ApplyOpts) error {
 
 	return cmd.Run()
 }
-
-func filterNamespace(in manifest.List) manifest.List {
-	return manifest.List(funk.Filter(in, func(i manifest.Manifest) bool {
-		return strings.ToLower(i.Kind()) == "namespace"
-	}).([]manifest.Manifest))
-}

pkg/kubernetes/reconcile.go

@@ -14,6 +14,44 @@ import (
 	"github.com/grafana/tanka/pkg/spec/v1alpha1"
 )
 
+// Order in which install different kinds of Kubernetes objects.
+// Inspired by https://github.com/helm/helm/blob/8c84a0bc0376650bc3d7334eef0c46356c22fa36/pkg/releaseutil/kind_sorter.go
+var kindOrder = []string{
+	"Namespace",
+	"NetworkPolicy",
+	"ResourceQuota",
+	"LimitRange",
+	"PodSecurityPolicy",
+	"PodDisruptionBudget",
+	"ServiceAccount",
+	"Secret",
+	"ConfigMap",
+	"StorageClass",
+	"PersistentVolume",
+	"PersistentVolumeClaim",
+	"CustomResourceDefinition",
+	"ClusterRole",
+	"ClusterRoleList",
+	"ClusterRoleBinding",
+	"ClusterRoleBindingList",
+	"Role",
+	"RoleList",
+	"RoleBinding",
+	"RoleBindingList",
+	"Service",
+	"DaemonSet",
+	"Pod",
+	"ReplicationController",
+	"ReplicaSet",
+	"Deployment",
+	"HorizontalPodAutoscaler",
+	"StatefulSet",
+	"Job",
+	"CronJob",
+	"Ingress",
+	"APIService",
+}
+
 // Reconcile extracts kubernetes Manifests from raw evaluated jsonnet <kind>/<name>,
 // provided the manifests match the given regular expressions. It finds each manifest by
 // recursively walking the jsonnet structure.
@@ -49,9 +87,33 @@ func Reconcile(raw map[string]interface{}, spec v1alpha1.Spec, targets []*regexp
 
 	// Stable output order
 	sort.SliceStable(out, func(i int, j int) bool {
+		var io, jo int
+
+		// anything that is not in kindOrder will get to the end of the install list.
+		for io = 0; io < len(kindOrder); io++ {
+			if out[i].Kind() == kindOrder[io] {
+				break
+			}
+		}
+
+		for jo = 0; jo < len(kindOrder); jo++ {
+			if out[j].Kind() == kindOrder[jo] {
+				break
+			}
+		}
+
+		// If Kind of both objects are at different indexes of kindOrder, sort by them
+		if io != jo {
+			return io < jo
+		}
+
+		// If the Kinds themselves are different (e.g. both of the Kinds are not in
+		// the kindOrder), order alphabetically.
 		if out[i].Kind() != out[j].Kind() {
 			return out[i].Kind() < out[j].Kind()
 		}
+
+		// Otherwise, order the objects by name.
 		return out[i].Metadata().Name() < out[j].Metadata().Name()
 	})