ci(gcb): make 2 kaniko attempts (#13639)

ci/cloudbuild/cloudbuild.yaml

@@ -65,22 +65,47 @@ availableSecrets:
 logsBucket: 'gs://${_LOGS_BUCKET}/logs/google-cloud-cpp/${_TRIGGER_SOURCE}/${COMMIT_SHA}/${_DISTRO}-${_BUILD_NAME}-${_SHARD}'
 
 steps:
- # Builds the docker image that will be used by the main build step.
+ # Builds the docker image that will be used by the main build step. Makes 3
+ # attempts to workaround #6438.
 - name: 'gcr.io/kaniko-project/executor:v1.20.1'
+ id: 'kaniko-attempt-1'
  args: [
  '--log-format=text',
  '--context=dir:///workspace/ci',
  '--dockerfile=ci/cloudbuild/dockerfiles/${_DISTRO}.Dockerfile',
  '--cache=true',
  '--destination=gcr.io/${PROJECT_ID}/${_IMAGE}:${BUILD_ID}',
- '--push-retry=3',
  '--image-fs-extract-retry=3',
- '--image-download-retry=3'
-]
+ '--image-download-retry=3',
+ '--push-retry=3'
+ ]
+ allowFailure: true
+
+ # Pull the docker image. The step running 'ci/cloud/build.sh' would do this
+ # automatically, and also fill the log with about 2-3 pages of noise.
+- name: 'gcr.io/${PROJECT_ID}/${_IMAGE}:${BUILD_ID}'
+ id: 'download-runner-image-attempt-1'
+ entrypoint: '/bin/true'
+
+- name: 'gcr.io/kaniko-project/executor:v1.20.1'
+ id: 'kaniko-attempt-2'
+ waitFor: [ 'kaniko-attempt-1' ]
+ args: [
+ '--log-format=text',
+ '--context=dir:///workspace/ci',
+ '--dockerfile=ci/cloudbuild/dockerfiles/${_DISTRO}.Dockerfile',
+ '--cache=true',
+ '--destination=gcr.io/${PROJECT_ID}/${_IMAGE}:${BUILD_ID}',
+ '--image-fs-extract-retry=3',
+ '--image-download-retry=3',
+ '--push-retry=3'
+ ]
+ allowFailure: true
 
  # Pull the docker image. The step running 'ci/cloud/build.sh' would do this
  # automatically, and also fill the log with about 2-3 pages of noise.
 - name: 'gcr.io/${PROJECT_ID}/${_IMAGE}:${BUILD_ID}'
+ id: 'download-runner-image-attempt-2'
  entrypoint: '/bin/true'
 
  # Restores the homedir cache into /h in parallel with the previous step.