Implement suspend, resume, reconcile image-update

.. and refactor. These are all amenable to the adapter refactoring
that has served well so far.

Signed-off-by: Michael Bridgen <michael@weave.works>

cmd/flux/status.go

@@ -0,0 +1,67 @@
+/*
+Copyright 2020 The Flux authors
+
+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 main
+
+import (
+	"context"
+	"fmt"
+
+	apimeta "k8s.io/apimachinery/pkg/api/meta"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/types"
+	"k8s.io/apimachinery/pkg/util/wait"
+	"sigs.k8s.io/controller-runtime/pkg/client"
+
+	"github.com/fluxcd/pkg/apis/meta"
+)
+
+// statusable is used to see if a resource is considered ready in the usual way
+type statusable interface {
+	adapter
+	// this is implemented by ObjectMeta
+	GetGeneration() int64
+	getObservedGeneration() int64
+	// this is usually implemented by GOTK API objects because it's used by pkg/apis/meta
+	GetStatusConditions() *[]metav1.Condition
+	// successMessage gives a short summary of the successful reconciliation
+	successMessage() string
+}
+
+func isReady(ctx context.Context, kubeClient client.Client,
+	namespacedName types.NamespacedName, object statusable) wait.ConditionFunc {
+	return func() (bool, error) {
+		err := kubeClient.Get(ctx, namespacedName, object.asRuntimeObject())
+		if err != nil {
+			return false, err
+		}
+
+		// Confirm the state we are observing is for the current generation
+		if object.GetGeneration() != object.getObservedGeneration() {
+			return false, nil
+		}
+
+		if c := apimeta.FindStatusCondition(*object.GetStatusConditions(), meta.ReadyCondition); c != nil {
+			switch c.Status {
+			case metav1.ConditionTrue:
+				return true, nil
+			case metav1.ConditionFalse:
+				return false, fmt.Errorf(c.Message)
+			}
+		}
+		return false, nil
+	}
+}