From 3e84799644ced2b2e074de29fc7211c085b55a58 Mon Sep 17 00:00:00 2001
From: stefanprodan <stefan.prodan@gmail.com>
Date: Tue, 9 Jul 2019 08:52:31 +0300
Subject: [PATCH] Detect changes in pod template metadata Use the pod template
 spec hash to track changes (breaking)

---
 go.mod                 |  1 +
 pkg/canary/deployer.go | 21 ++++++---------------
 pkg/canary/status.go   | 15 +++++++--------
 3 files changed, 14 insertions(+), 23 deletions(-)

diff --git a/go.mod b/go.mod
index 4755ac4f..7100be67 100644
--- a/go.mod
+++ b/go.mod
@@ -30,6 +30,7 @@ require (
 	github.com/mattn/go-isatty v0.0.7 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/mitchellh/go-testing-interface v1.0.0 // indirect
+	github.com/mitchellh/hashstructure v1.0.0
 	github.com/prometheus/client_golang v0.9.3-0.20190127221311-3c4408c8b829
 	github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90 // indirect
 	github.com/prometheus/common v0.3.0 // indirect
diff --git a/pkg/canary/deployer.go b/pkg/canary/deployer.go
index 98485d2a..aa83eab3 100644
--- a/pkg/canary/deployer.go
+++ b/pkg/canary/deployer.go
@@ -2,20 +2,18 @@ package canary
 
 import (
 	"crypto/rand"
-	"encoding/base64"
-	"encoding/json"
 	"fmt"
+	"io"
+
 	"github.com/google/go-cmp/cmp"
-	"github.com/google/go-cmp/cmp/cmpopts"
+	"github.com/mitchellh/hashstructure"
 	flaggerv1 "github.com/weaveworks/flagger/pkg/apis/flagger/v1alpha3"
 	clientset "github.com/weaveworks/flagger/pkg/client/clientset/versioned"
 	"go.uber.org/zap"
-	"io"
 	appsv1 "k8s.io/api/apps/v1"
 	hpav1 "k8s.io/api/autoscaling/v2beta1"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/errors"
-	"k8s.io/apimachinery/pkg/api/resource"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	"k8s.io/client-go/kubernetes"
@@ -146,19 +144,12 @@ func (c *Deployer) HasDeploymentChanged(cd *flaggerv1.Canary) (bool, error) {
 		return true, nil
 	}
 
-	newSpec := &canary.Spec.Template.Spec
-	oldSpecJson, err := base64.StdEncoding.DecodeString(cd.Status.LastAppliedSpec)
+	newHash, err := hashstructure.Hash(canary.Spec.Template, nil)
 	if err != nil {
-		return false, fmt.Errorf("%s.%s decode error %v", cd.Name, cd.Namespace, err)
-	}
-	oldSpec := &corev1.PodSpec{}
-	err = json.Unmarshal(oldSpecJson, oldSpec)
-	if err != nil {
-		return false, fmt.Errorf("%s.%s unmarshal error %v", cd.Name, cd.Namespace, err)
+		return false, fmt.Errorf("hash error %v", err)
 	}
 
-	if diff := cmp.Diff(*newSpec, *oldSpec, cmpopts.IgnoreUnexported(resource.Quantity{})); diff != "" {
-		//fmt.Println(diff)
+	if cd.Status.LastAppliedSpec != fmt.Sprintf("%d", newHash) {
 		return true, nil
 	}
 
diff --git a/pkg/canary/status.go b/pkg/canary/status.go
index e613e570..7c2cb317 100644
--- a/pkg/canary/status.go
+++ b/pkg/canary/status.go
@@ -1,10 +1,9 @@
 package canary
 
 import (
-	"encoding/base64"
-	"encoding/json"
 	"fmt"
 
+	"github.com/mitchellh/hashstructure"
 	flaggerv1 "github.com/weaveworks/flagger/pkg/apis/flagger/v1alpha3"
 	"k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -20,22 +19,22 @@ func (c *Deployer) SyncStatus(cd *flaggerv1.Canary, status flaggerv1.CanaryStatu
 		return fmt.Errorf("deployment %s.%s query error %v", cd.Spec.TargetRef.Name, cd.Namespace, err)
 	}
 
-	specJson, err := json.Marshal(dep.Spec.Template.Spec)
-	if err != nil {
-		return fmt.Errorf("deployment %s.%s marshal error %v", cd.Spec.TargetRef.Name, cd.Namespace, err)
-	}
-
 	configs, err := c.ConfigTracker.GetConfigRefs(cd)
 	if err != nil {
 		return fmt.Errorf("configs query error %v", err)
 	}
 
+	hash, err := hashstructure.Hash(dep.Spec.Template, nil)
+	if err != nil {
+		return fmt.Errorf("hash error %v", err)
+	}
+
 	cdCopy := cd.DeepCopy()
 	cdCopy.Status.Phase = status.Phase
 	cdCopy.Status.CanaryWeight = status.CanaryWeight
 	cdCopy.Status.FailedChecks = status.FailedChecks
 	cdCopy.Status.Iterations = status.Iterations
-	cdCopy.Status.LastAppliedSpec = base64.StdEncoding.EncodeToString(specJson)
+	cdCopy.Status.LastAppliedSpec = fmt.Sprintf("%d", hash)
 	cdCopy.Status.LastTransitionTime = metav1.Now()
 	cdCopy.Status.TrackedConfigs = configs