Fix periodic runs of tekton workflows. (kubeflow#697)

* Fix periodic runs of tekton workflows.

* Periodic runs aren't associated with a repository/commit; so we shouldn't
  try to substitute into the pipelineruns.

* Add exception handling so we keep going if a workflow has an exception.

* Fix: kubeflow#696

* Fix some whitespace in apps-cd/README.md

apps-cd/README.md

@@ -169,7 +169,6 @@ This is a Kubeflow cluster (v0.6.2) and we rely on that to configure certain thi
 
    ```
    kustomize build pipelines/overlays/prod | kubectl --context=kf-releasing apply -f -
-
    ```
 ## Developer Guide
 

py/kubeflow/testing/run_e2e_workflow.py

@@ -68,6 +68,7 @@
 import uuid
 import subprocess
 import sys
+import traceback
 import yaml
 
 # The name of the command line argument for workflows for the var
@@ -372,14 +373,20 @@ def run(args, file_handler): # pylint: disable=too-many-statements,too-many-bran
       else:
         pull_revision = "master"
       logging.info("Adding Tekton pipeline %s", w.name)
-      pipeline_runner = tekton_client.PipelineRunner(
-          w.tekton_params,
-          w.kwargs.get(TEST_TARGET_ARG_NAME, w.name),
-          w.tekton_run,
-          args.bucket,
-          repo_owner,
-          repo_name,
-          pull_revision)
+      try:
+        pipeline_runner = tekton_client.PipelineRunner(
+            w.tekton_params,
+            w.kwargs.get(TEST_TARGET_ARG_NAME, w.name),
+            w.tekton_run,
+            args.bucket,
+            repo_owner,
+            repo_name,
+            pull_revision)
+      except (FileNotFoundError, ValueError) as e:
+        logging.error("Error when starting Tekton workflow:%s\n Exception %s;\n"
+                      "stacktrace:\n%s",
+                      w.tekton_run, e, traceback.format_exc())
+        continue
       if w.tekton_teardown:
         logging.info("Appending teardown process for Tekton pipeline %s",
                      w.name)

py/kubeflow/testing/tekton_client.py

@@ -126,7 +126,7 @@ def get_namespaced_custom_object_with_retries(namespace, name):
 # and GCS path when running multiple workflows from the same prow test.
 # Can this be done in the Pipeline and Task resources by appending
 # unique subdirectories to the paths?
-def load_tekton_run(params, test_target_name, tekton_run,
+def load_tekton_run(params, test_target_name, tekton_run, # pylint: disable=too-many-branches
                     bucket, repo_owner, repo_under_test, pull_revision):
   """Load Tekton configs and override information from Prow.
   Args:
@@ -179,22 +179,29 @@ def load_tekton_run(params, test_target_name, tekton_run,
       {"name": "url", "value": repo_url},
       {"name": "revision", "value": pull_revision},
   ]
-  foundRepo = False
-  for resource in config["spec"].get("resources", []):
-    if resource.get("resourceSpec", {}).get("type", "") != "git":
-      pass
-    for param in resource.get("resourceSpec", {}).get("params", []):
-      if param.get("name", "") != "url":
-        continue
-      if param.get("value", "") == repo_url:
-        foundRepo = True
-        resource["resourceSpec"]["params"] = replacing_param
-        break
-  if not foundRepo:
-    raise ValueError(("The TektonPipelineRun is missing a pipeline git "
-                      "resource that matches the repo being tested by "
-                      "prow. The pipeline parameters must include "
-                      "a git resource whose URL is {0}".format(repo_url)))
+
+  job_type = os.getenv("JOB_TYPE", "").lower()
+
+  if job_type in ["presubmit", "postsubmit"]:
+    logging.info("Job is type %s; looking for url %s", job_type, repo_url)
+    foundRepo = False
+    for resource in config["spec"].get("resources", []):
+      if resource.get("resourceSpec", {}).get("type", "") != "git":
+        pass
+      for param in resource.get("resourceSpec", {}).get("params", []):
+        if param.get("name", "") != "url":
+          continue
+        if param.get("value", "") == repo_url:
+          foundRepo = True
+          resource["resourceSpec"]["params"] = replacing_param
+          break
+    if not foundRepo:
+      raise ValueError(("The TektonPipelineRun is missing a pipeline git "
+                        "resource that matches the repo being tested by "
+                        "prow. The pipeline parameters must include "
+                        "a git resource whose URL is {0}".format(repo_url)))
+  else:
+    logging.info("Job is type %s; not looking for repo", job_type)
 
   return config