show server version in ark version output using ServerStatusRequest CRD

Signed-off-by: Steve Kriss <steve@heptio.com>

pkg/serverstatusrequest/process.go

@@ -0,0 +1,90 @@
+/*
+Copyright 2018 the Heptio Ark contributors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package serverstatusrequest
+
+import (
+	"encoding/json"
+	"time"
+
+	jsonpatch "github.com/evanphx/json-patch"
+	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/clock"
+
+	arkv1api "github.com/heptio/ark/pkg/apis/ark/v1"
+	"github.com/heptio/ark/pkg/buildinfo"
+	arkv1client "github.com/heptio/ark/pkg/generated/clientset/versioned/typed/ark/v1"
+)
+
+const ttl = time.Minute
+
+// Process fills out new ServerStatusRequest objects and deletes processed ones
+// that have expired.
+func Process(req *arkv1api.ServerStatusRequest, client arkv1client.ServerStatusRequestsGetter, clock clock.Clock, log logrus.FieldLogger) error {
+	switch req.Status.Phase {
+	case "", arkv1api.ServerStatusRequestPhaseNew:
+		log.Info("Processing new ServerStatusRequest")
+		return errors.WithStack(patch(client, req, func(req *arkv1api.ServerStatusRequest) {
+			req.Status.ServerVersion = buildinfo.Version
+			req.Status.ProcessedTimestamp.Time = clock.Now()
+			req.Status.Phase = arkv1api.ServerStatusRequestPhaseProcessed
+		}))
+	case arkv1api.ServerStatusRequestPhaseProcessed:
+		log.Debug("Checking whether ServerStatusRequest has expired")
+		expiration := req.Status.ProcessedTimestamp.Add(ttl)
+		if expiration.After(clock.Now()) {
+			log.Debug("ServerStatusRequest has not expired")
+			return nil
+		}
+
+		log.Debug("ServerStatusRequest has expired, deleting it")
+		if err := client.ServerStatusRequests(req.Namespace).Delete(req.Name, nil); err != nil {
+			return errors.WithStack(err)
+		}
+
+		return nil
+	default:
+		return errors.Errorf("unexpected ServerStatusRequest phase %q", req.Status.Phase)
+	}
+}
+
+func patch(client arkv1client.ServerStatusRequestsGetter, req *arkv1api.ServerStatusRequest, updateFunc func(*arkv1api.ServerStatusRequest)) error {
+	originalJSON, err := json.Marshal(req)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	updateFunc(req)
+
+	updatedJSON, err := json.Marshal(req)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	patchBytes, err := jsonpatch.CreateMergePatch(originalJSON, updatedJSON)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	_, err = client.ServerStatusRequests(req.Namespace).Patch(req.Name, types.MergePatchType, patchBytes)
+	if err != nil {
+		return errors.WithStack(err)
+	}
+
+	return nil
+}