cloudbuild.yaml: build using make

Use make for building our container image (through a new push-image.sh
script) instead of building directly with docker. This way we avoid the
container image tag naming hassle where we build and push the image on
"image-pushing" prow job and need to be able to reliably re-create the
same tag on the "testing" side for end-to-end tests. This also has the
advantage that the same mechanism (make) is used everywhere, i.e. in
image-pushing, testing and locally.

cloudbuild.yaml

@@ -1,20 +1,10 @@
 steps:
-  - name: gcr.io/cloud-builders/docker
-    args:
-    - 'build'
-    - '--build-arg=VERSION=$_GIT_TAG'
-    - '--build-arg=HOSTMOUNT_PREFIX=/host-'
-    - '--tag=gcr.io/$PROJECT_ID/node-feature-discovery:$_GIT_TAG'
-    - '--tag=gcr.io/$PROJECT_ID/node-feature-discovery:$_PULL_BASE_REF'
-    - '--tag=gcr.io/$PROJECT_ID/node-feature-discovery:$_PULL_BASE_REF-g$COMMIT_SHA'
-    - '.'
+  - name: gcr.io/k8s-testimages/gcb-docker-gcloud:v20200824-5d057db
+    entrypoint: scripts/test-infra/push-image.sh
+    env:
+    - IMAGE_EXTRA_TAG_NAMES=$_PULL_BASE_REF
 substitutions:
   _GIT_TAG: '0.0.0'
   _PULL_BASE_REF: 'master'
 options:
   substitution_option: ALLOW_LOOSE
-# Pust images
-images:
-  - 'gcr.io/$PROJECT_ID/node-feature-discovery:$_GIT_TAG'
-  - 'gcr.io/$PROJECT_ID/node-feature-discovery:$_PULL_BASE_REF'
-  - 'gcr.io/$PROJECT_ID/node-feature-discovery:$_PULL_BASE_REF-g$COMMIT_SHA'

scripts/test-infra/push-image.sh

@@ -0,0 +1,4 @@
+#!/bin/bash -e
+
+make image -e
+make push -e