refactor: use a pointer for field skipAnalysis in CanarySpec

This refactor tries to fulfil a special use case fluxcd#1660: when a custom
controller uses the Flagger API to render the Canary object to
json/yaml, it makes sure the skipAnalysis field is rendered when the
value is "false", so that the field is always communicated to the k8s
API server.

Comparison is as follows:

before, when skipAnalysis is "false" the canary object is rendered as such:

```
apiVersion: flagger.app/v1beta1
kind: Canary
...
spec:
  analysis:
...
```

After, it is as such:
```
apiVersion: flagger.app/v1beta1
kind: Canary
...
spec:
  skipAnalysis: false # this is the field we expected
  analysis:
...
```

Author: bruce-personio

pkg/apis/flagger/v1beta1/canary.go

@@ -105,7 +105,7 @@ type CanarySpec struct {
 
 	// SkipAnalysis promotes the canary without analysing it
 	// +optional
-	SkipAnalysis bool `json:"skipAnalysis,omitempty"`
+	SkipAnalysis *bool `json:"skipAnalysis,omitempty"`
 
 	// revert canary mutation on deletion of canary resource
 	// +optional
@@ -615,8 +615,13 @@ func (c *Canary) GetMetricInterval() string {
 // SkipAnalysis returns true if the analysis is nil
 // or if spec.SkipAnalysis is true
 func (c *Canary) SkipAnalysis() bool {
+	if c.Spec.SkipAnalysis == nil {
+		return false
+	}
+
 	if c.Spec.Analysis == nil && c.Spec.CanaryAnalysis == nil {
 		return true
 	}
-	return c.Spec.SkipAnalysis
+
+	return *c.Spec.SkipAnalysis
 }

pkg/controller/scheduler_daemonset_test.go

@@ -110,7 +110,8 @@ func TestScheduler_DaemonSetSkipAnalysis(t *testing.T) {
 	cd, err := mocks.flaggerClient.FlaggerV1beta1().Canaries("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
 	require.NoError(t, err)
 
-	cd.Spec.SkipAnalysis = true
+	skipAnalysis := true
+	cd.Spec.SkipAnalysis = &skipAnalysis
 	_, err = mocks.flaggerClient.FlaggerV1beta1().Canaries("default").Update(context.TODO(), cd, metav1.UpdateOptions{})
 	require.NoError(t, err)
 
@@ -126,7 +127,7 @@ func TestScheduler_DaemonSetSkipAnalysis(t *testing.T) {
 
 	c, err := mocks.flaggerClient.FlaggerV1beta1().Canaries("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
 	require.NoError(t, err)
-	assert.True(t, c.Spec.SkipAnalysis)
+	assert.True(t, c.SkipAnalysis())
 	assert.Equal(t, flaggerv1.CanaryPhaseSucceeded, c.Status.Phase)
 }
 

pkg/controller/scheduler_deployment_test.go

@@ -130,7 +130,8 @@ func TestScheduler_DeploymentSkipAnalysis(t *testing.T) {
 	// enable skip
 	cd, err := mocks.flaggerClient.FlaggerV1beta1().Canaries("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
 	require.NoError(t, err)
-	cd.Spec.SkipAnalysis = true
+	skipAnalysis := true
+	cd.Spec.SkipAnalysis = &skipAnalysis
 	_, err = mocks.flaggerClient.FlaggerV1beta1().Canaries("default").Update(context.TODO(), cd, metav1.UpdateOptions{})
 	require.NoError(t, err)
 
@@ -148,7 +149,7 @@ func TestScheduler_DeploymentSkipAnalysis(t *testing.T) {
 
 	c, err := mocks.flaggerClient.FlaggerV1beta1().Canaries("default").Get(context.TODO(), "podinfo", metav1.GetOptions{})
 	require.NoError(t, err)
-	assert.True(t, c.Spec.SkipAnalysis)
+	assert.True(t, c.SkipAnalysis())
 	assert.Equal(t, flaggerv1.CanaryPhaseSucceeded, c.Status.Phase)
 }