azurepathfixjob: recreate job when detect changes to container env vars

the storage controller sometimes recreates the storage account after the
job has been created. to account for that, we compare the container envs
between created and desired values, and when they differ we recreate the
job.

Author: flavianmissi

pkg/resource/azurepathfixjob.go

@@ -4,12 +4,14 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"reflect"
 
 	batchv1 "k8s.io/api/batch/v1"
 	corev1 "k8s.io/api/core/v1"
 	kcorev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/api/errors"
 	"k8s.io/apimachinery/pkg/api/resource"
+	metaapi "k8s.io/apimachinery/pkg/apis/meta/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	batchset "k8s.io/client-go/kubernetes/typed/batch/v1"
@@ -269,11 +271,39 @@ func (gapfj *generatorAzurePathFixJob) Create() (runtime.Object, error) {
 }
 
 func (gapfj *generatorAzurePathFixJob) Update(o runtime.Object) (runtime.Object, bool, error) {
-	return commonUpdate(gapfj, o, func(obj runtime.Object) (runtime.Object, error) {
-		return gapfj.client.Jobs(gapfj.GetNamespace()).Update(
-			context.TODO(), obj.(*batchv1.Job), metav1.UpdateOptions{},
-		)
-	})
+	// updating jobs doesn't work like other objects - we get validation errors
+	// if we try. in our case, we only care about the job container's env vars,
+	// so we check if the existing job's container env vars match the expected,
+	// and if they don't we recreate the job.
+	exp, err := gapfj.expected()
+	if err != nil {
+		return nil, false, err
+	}
+	expectedJob := exp.(*batchv1.Job)
+	job := o.(*batchv1.Job)
+	expectedEnvs := expectedJob.Spec.Template.Spec.Containers[0].Env
+	actualEnvs := job.Spec.Template.Spec.Containers[0].Env
+
+	if reflect.DeepEqual(expectedEnvs, actualEnvs) {
+		return o, false, nil
+	}
+
+	// if we are here it means the expected container envs differed from
+	// the actual container envs, so we recreate the job.
+	gracePeriod := int64(0)
+	propagationPolicy := metaapi.DeletePropagationForeground
+	opts := metaapi.DeleteOptions{
+		GracePeriodSeconds: &gracePeriod,
+		PropagationPolicy:  &propagationPolicy,
+	}
+	if err := gapfj.Delete(opts); err != nil {
+		return nil, false, err
+	}
+	createdObj, err := gapfj.Create()
+	if err != nil {
+		return nil, false, err
+	}
+	return createdObj, true, nil
 }
 
 func (gapfj *generatorAzurePathFixJob) Delete(opts metav1.DeleteOptions) error {