Add --force flag when deploying with kubectl

The --force flag will delete and redeploy a deployment if 'kubectl
apply' doesn't work because a field is immutable. Updated the skaffold
deploy Dockerfile to reflect this change, added a note in the docs that
kubectl > 1.12.0 is recommended, and added a check in the kubectl
deployer for the version.

Author: Priya Wadhwa

deploy/skaffold/Dockerfile

@@ -18,7 +18,7 @@ RUN apt-get update && \
     apt-get install --no-install-recommends --no-install-suggests -y \
         python-dev
 
-ENV KUBECTL_VERSION v1.10.0
+ENV KUBECTL_VERSION v1.12.0
 RUN curl -Lo /usr/local/bin/kubectl https://storage.googleapis.com/kubernetes-release/release/${KUBECTL_VERSION}/bin/linux/amd64/kubectl  && \
     chmod +x /usr/local/bin/kubectl
 

docs/concepts.adoc

@@ -28,6 +28,8 @@ tools for deployment, for example `kubectl` or `helm`.
 Each deployment type has parameters that allow you to
 define how you want your app to be installed and updated.
 
+_Note: kubectl version 1.12.0 or greater is recommended for use with skaffold._
+
 === Artifact
 Artifacts are the outputs of the build phase.
 Artifacts are created by running a set of steps on some

examples/test-dev-job/Dockerfile renamed to integration/examples/test-dev-job/Dockerfile

@@ -1,4 +1,4 @@
-apiVersion: skaffold/v1alpha2
+apiVersion: skaffold/v1alpha4
 kind: Config
 build:
   artifacts:

examples/test-dev-job/k8s-job.yaml renamed to integration/examples/test-dev-job/k8s-job.yaml

@@ -221,17 +221,17 @@ func TestDev(t *testing.T) {
 	testCases := []testDevCase{
 		{
 			description: "delete and redeploy job",
-			dir:         "../examples/test-dev-job",
+			dir:         "examples/test-dev-job",
 			args:        []string{"dev"},
 			setup: func(t *testing.T) func(t *testing.T) {
 				// create foo
-				cmd := exec.Command("touch", "../examples/test-dev-job/foo")
+				cmd := exec.Command("touch", "examples/test-dev-job/foo")
 				if output, err := util.RunCmdOut(cmd); err != nil {
 					t.Fatalf("creating foo: %s %v", output, err)
 				}
 				return func(t *testing.T) {
 					// delete foo
-					cmd := exec.Command("rm", "../examples/test-dev-job/foo")
+					cmd := exec.Command("rm", "examples/test-dev-job/foo")
 					if output, err := util.RunCmdOut(cmd); err != nil {
 						t.Fatalf("creating foo: %s %v", output, err)
 					}
@@ -243,7 +243,7 @@ func TestDev(t *testing.T) {
 			jobValidation: func(t *testing.T, ns *v1.Namespace, j *batchv1.Job) {
 				originalUID := j.GetUID()
 				// Make a change to foo so that dev is forced to delete the job and redeploy
-				cmd := exec.Command("sh", "-c", "echo bar > ../examples/test-dev-job/foo")
+				cmd := exec.Command("sh", "-c", "echo bar > examples/test-dev-job/foo")
 				if output, err := util.RunCmdOut(cmd); err != nil {
 					t.Fatalf("creating bar: %s %v", output, err)
 				}
@@ -256,7 +256,7 @@ func TestDev(t *testing.T) {
 					return originalUID != newJob.GetUID(), nil
 				})
 				if err != nil {
-					t.Fatalf("original UID and new UID are the same, redeploy failed")
+					t.Fatalf("redeploy failed: %v", err)
 				}
 			},
 		},

examples/test-dev-job/skaffold.yaml renamed to integration/examples/test-dev-job/skaffold.yaml

@@ -187,7 +187,3 @@ func (k *KubectlDeployer) readRemoteManifest(ctx context.Context, name string) (
 
 	return manifest.Bytes(), nil
 }
-
-func checkKubectlVersion() error {
-
-}