chore: add kokoro templates (#160)

* build(python): enable flakybot on library unit and system tests

Source-Author: Bu Sun Kim <8822365+busunkim96@users.noreply.github.com>
Source-Date: Wed Feb 17 14:10:46 2021 -0700
Source-Repo: googleapis/synthtool
Source-Sha: d17674372e27fb8f23013935e794aa37502071aa
Source-Link: https://github.com/googleapis/synthtool/commit/d17674372e27fb8f23013935e794aa37502071aa

* chore: add pre-commit-config to renovate ignore paths

Disable renovate PRs on the .pre-commit-config.yaml which is templated from synthtool. https://docs.renovatebot.com/configuration-options/#ignorepaths

Source-Author: Bu Sun Kim <8822365+busunkim96@users.noreply.github.com>
Source-Date: Mon Mar 15 09:05:39 2021 -0600
Source-Repo: googleapis/synthtool
Source-Sha: 2c54c473779ea731128cea61a3a6c975a08a5378
Source-Link: https://github.com/googleapis/synthtool/commit/2c54c473779ea731128cea61a3a6c975a08a5378

* chore(python): add kokoro configs for periodic builds against head

This change should be non-destructive.

Note for library repo maintainers:
After applying this change, you can easily add (or change) periodic
builds against head by adding config files in google3.

See python-pubsub repo for example.

Source-Author: Takashi Matsuo <tmatsuo@google.com>
Source-Date: Fri Mar 19 11:17:59 2021 -0700
Source-Repo: googleapis/synthtool
Source-Sha: 79c8dd7ee768292f933012d3a69a5b4676404cda
Source-Link: https://github.com/googleapis/synthtool/commit/79c8dd7ee768292f933012d3a69a5b4676404cda

* chore(deps): update precommit hook pycqa/flake8 to v3.9.0

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This PR contains the following updates:

| Package | Type | Update | Change |
|---|---|---|---|
| [pycqa/flake8](https://gitlab.com/pycqa/flake8) | repository | minor | `3.8.4` -> `3.9.0` |

---

### Release Notes

<details>
<summary>pycqa/flake8</summary>

### [`v3.9.0`](https://gitlab.com/pycqa/flake8/compare/3.8.4...3.9.0)

[Compare Source](https://gitlab.com/pycqa/flake8/compare/3.8.4...3.9.0)

</details>

---

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:recycle: **Rebasing**: Whenever PR becomes conflicted, or you tick the rebase/retry checkbox.

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This PR has been generated by [WhiteSource Renovate](https://renovate.whitesourcesoftware.com). View repository job log [here](https://app.renovatebot.com/dashboard#github/googleapis/synthtool).

Source-Author: WhiteSource Renovate <bot@renovateapp.com>
Source-Date: Tue Mar 23 17:38:03 2021 +0100
Source-Repo: googleapis/synthtool
Source-Sha: f5c5904fb0c6aa3b3730eadf4e5a4485afc65726
Source-Link: https://github.com/googleapis/synthtool/commit/f5c5904fb0c6aa3b3730eadf4e5a4485afc65726

7 files changed, 189 insertions, 80 deletions

diff --git a/.kokoro/build.sh b/.kokoro/build.sh
index 41a88d5..8b9fd8a 100755
--- a/.kokoro/build.sh
+++ b/.kokoro/build.sh
@@ -40,6 +40,16 @@ python3 -m pip uninstall --yes --quiet nox-automation
 python3 -m pip install --upgrade --quiet nox
 python3 -m nox --version
 
+# If this is a continuous build, send the test log to the FlakyBot.
+# See https://github.com/googleapis/repo-automation-bots/tree/master/packages/flakybot.
+if [[ $KOKORO_BUILD_ARTIFACTS_SUBDIR = *"continuous"* ]]; then
+  cleanup() {
+    chmod +x $KOKORO_GFILE_DIR/linux_amd64/flakybot
+    $KOKORO_GFILE_DIR/linux_amd64/flakybot
+  }
+  trap cleanup EXIT HUP
+fi
+
 # If NOX_SESSION is set, it only runs the specified session,
 # otherwise run all the sessions.
 if [[ -n "${NOX_SESSION:-}" ]]; then
diff --git a/.kokoro/samples/python3.6/periodic-head.cfg b/.kokoro/samples/python3.6/periodic-head.cfg
new file mode 100644
index 0000000..f9cfcd3
--- /dev/null
+++ b/.kokoro/samples/python3.6/periodic-head.cfg
@@ -0,0 +1,11 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+env_vars: {
+    key: "INSTALL_LIBRARY_FROM_SOURCE"
+    value: "True"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_BUILD_FILE"
+    value: "github/python-pubsub/.kokoro/test-samples-against-head.sh"
+}
diff --git a/.kokoro/samples/python3.7/periodic-head.cfg b/.kokoro/samples/python3.7/periodic-head.cfg
new file mode 100644
index 0000000..f9cfcd3
--- /dev/null
+++ b/.kokoro/samples/python3.7/periodic-head.cfg
@@ -0,0 +1,11 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+env_vars: {
+    key: "INSTALL_LIBRARY_FROM_SOURCE"
+    value: "True"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_BUILD_FILE"
+    value: "github/python-pubsub/.kokoro/test-samples-against-head.sh"
+}
diff --git a/.kokoro/samples/python3.8/periodic-head.cfg b/.kokoro/samples/python3.8/periodic-head.cfg
new file mode 100644
index 0000000..f9cfcd3
--- /dev/null
+++ b/.kokoro/samples/python3.8/periodic-head.cfg
@@ -0,0 +1,11 @@
+# Format: //devtools/kokoro/config/proto/build.proto
+
+env_vars: {
+    key: "INSTALL_LIBRARY_FROM_SOURCE"
+    value: "True"
+}
+
+env_vars: {
+    key: "TRAMPOLINE_BUILD_FILE"
+    value: "github/python-pubsub/.kokoro/test-samples-against-head.sh"
+}
diff --git a/.kokoro/test-samples-against-head.sh b/.kokoro/test-samples-against-head.sh
new file mode 100755
index 0000000..a7858e4
--- /dev/null
+++ b/.kokoro/test-samples-against-head.sh
@@ -0,0 +1,28 @@
+#!/bin/bash
+# Copyright 2020 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# A customized test runner for samples.
+#
+# For periodic builds, you can specify this file for testing against head.
+
+# `-e` enables the script to automatically fail when a command fails
+# `-o pipefail` sets the exit code to the rightmost comment to exit with a non-zero
+set -eo pipefail
+# Enables `**` to include files nested inside sub-folders
+shopt -s globstar
+
+cd github/python-api-core
+
+exec .kokoro/test-samples-impl.sh
diff --git a/.kokoro/test-samples-impl.sh b/.kokoro/test-samples-impl.sh
new file mode 100755
index 0000000..cf5de74
--- /dev/null
+++ b/.kokoro/test-samples-impl.sh
@@ -0,0 +1,102 @@
+#!/bin/bash
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+# `-e` enables the script to automatically fail when a command fails
+# `-o pipefail` sets the exit code to the rightmost comment to exit with a non-zero
+set -eo pipefail
+# Enables `**` to include files nested inside sub-folders
+shopt -s globstar
+
+# Exit early if samples directory doesn't exist
+if [ ! -d "./samples" ]; then
+  echo "No tests run. `./samples` not found"
+  exit 0
+fi
+
+# Disable buffering, so that the logs stream through.
+export PYTHONUNBUFFERED=1
+
+# Debug: show build environment
+env | grep KOKORO
+
+# Install nox
+python3.6 -m pip install --upgrade --quiet nox
+
+# Use secrets acessor service account to get secrets
+if [[ -f "${KOKORO_GFILE_DIR}/secrets_viewer_service_account.json" ]]; then
+    gcloud auth activate-service-account \
+	   --key-file="${KOKORO_GFILE_DIR}/secrets_viewer_service_account.json" \
+	   --project="cloud-devrel-kokoro-resources"
+fi
+
+# This script will create 3 files:
+# - testing/test-env.sh
+# - testing/service-account.json
+# - testing/client-secrets.json
+./scripts/decrypt-secrets.sh
+
+source ./testing/test-env.sh
+export GOOGLE_APPLICATION_CREDENTIALS=$(pwd)/testing/service-account.json
+
+# For cloud-run session, we activate the service account for gcloud sdk.
+gcloud auth activate-service-account \
+       --key-file "${GOOGLE_APPLICATION_CREDENTIALS}"
+
+export GOOGLE_CLIENT_SECRETS=$(pwd)/testing/client-secrets.json
+
+echo -e "\n******************** TESTING PROJECTS ********************"
+
+# Switch to 'fail at end' to allow all tests to complete before exiting.
+set +e
+# Use RTN to return a non-zero value if the test fails.
+RTN=0
+ROOT=$(pwd)
+# Find all requirements.txt in the samples directory (may break on whitespace).
+for file in samples/**/requirements.txt; do
+    cd "$ROOT"
+    # Navigate to the project folder.
+    file=$(dirname "$file")
+    cd "$file"
+
+    echo "------------------------------------------------------------"
+    echo "- testing $file"
+    echo "------------------------------------------------------------"
+
+    # Use nox to execute the tests for the project.
+    python3.6 -m nox -s "$RUN_TESTS_SESSION"
+    EXIT=$?
+
+    # If this is a periodic build, send the test log to the FlakyBot.
+    # See https://github.com/googleapis/repo-automation-bots/tree/master/packages/flakybot.
+    if [[ $KOKORO_BUILD_ARTIFACTS_SUBDIR = *"periodic"* ]]; then
+      chmod +x $KOKORO_GFILE_DIR/linux_amd64/flakybot
+      $KOKORO_GFILE_DIR/linux_amd64/flakybot
+    fi
+
+    if [[ $EXIT -ne 0 ]]; then
+      RTN=1
+      echo -e "\n Testing failed: Nox returned a non-zero exit code. \n"
+    else
+      echo -e "\n Testing completed.\n"
+    fi
+
+done
+cd "$ROOT"
+
+# Workaround for Kokoro permissions issue: delete secrets
+rm testing/{test-env.sh,client-secrets.json,service-account.json}
+
+exit "$RTN"
diff --git a/.kokoro/test-samples.sh b/.kokoro/test-samples.sh
index c0b4bdc..ee3146b 100755
--- a/.kokoro/test-samples.sh
+++ b/.kokoro/test-samples.sh
@@ -13,6 +13,10 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
+# The default test runner for samples.
+#
+# For periodic builds, we rewinds the repo to the latest release, and
+# run test-samples-impl.sh.
 
 # `-e` enables the script to automatically fail when a command fails
 # `-o pipefail` sets the exit code to the rightmost comment to exit with a non-zero
@@ -24,87 +28,19 @@ cd github/python-api-core
 
 # Run periodic samples tests at latest release
 if [[ $KOKORO_BUILD_ARTIFACTS_SUBDIR = *"periodic"* ]]; then
+    # preserving the test runner implementation.
+    cp .kokoro/test-samples-impl.sh "${TMPDIR}/test-samples-impl.sh"
+    echo "--- IMPORTANT IMPORTANT IMPORTANT ---"
+    echo "Now we rewind the repo back to the latest release..."
     LATEST_RELEASE=$(git describe --abbrev=0 --tags)
     git checkout $LATEST_RELEASE
-fi
-
-# Exit early if samples directory doesn't exist
-if [ ! -d "./samples" ]; then
-  echo "No tests run. `./samples` not found"
-  exit 0
-fi
-
-# Disable buffering, so that the logs stream through.
-export PYTHONUNBUFFERED=1
-
-# Debug: show build environment
-env | grep KOKORO
-
-# Install nox
-python3.6 -m pip install --upgrade --quiet nox
-
-# Use secrets acessor service account to get secrets
-if [[ -f "${KOKORO_GFILE_DIR}/secrets_viewer_service_account.json" ]]; then
-    gcloud auth activate-service-account \
-	   --key-file="${KOKORO_GFILE_DIR}/secrets_viewer_service_account.json" \
-	   --project="cloud-devrel-kokoro-resources"
-fi
-
-# This script will create 3 files:
-# - testing/test-env.sh
-# - testing/service-account.json
-# - testing/client-secrets.json
-./scripts/decrypt-secrets.sh
-
-source ./testing/test-env.sh
-export GOOGLE_APPLICATION_CREDENTIALS=$(pwd)/testing/service-account.json
-
-# For cloud-run session, we activate the service account for gcloud sdk.
-gcloud auth activate-service-account \
-       --key-file "${GOOGLE_APPLICATION_CREDENTIALS}"
-
-export GOOGLE_CLIENT_SECRETS=$(pwd)/testing/client-secrets.json
-
-echo -e "\n******************** TESTING PROJECTS ********************"
-
-# Switch to 'fail at end' to allow all tests to complete before exiting.
-set +e
-# Use RTN to return a non-zero value if the test fails.
-RTN=0
-ROOT=$(pwd)
-# Find all requirements.txt in the samples directory (may break on whitespace).
-for file in samples/**/requirements.txt; do
-    cd "$ROOT"
-    # Navigate to the project folder.
-    file=$(dirname "$file")
-    cd "$file"
-
-    echo "------------------------------------------------------------"
-    echo "- testing $file"
-    echo "------------------------------------------------------------"
-
-    # Use nox to execute the tests for the project.
-    python3.6 -m nox -s "$RUN_TESTS_SESSION"
-    EXIT=$?
-
-    # If this is a periodic build, send the test log to the FlakyBot.
-    # See https://github.com/googleapis/repo-automation-bots/tree/master/packages/flakybot.
-    if [[ $KOKORO_BUILD_ARTIFACTS_SUBDIR = *"periodic"* ]]; then
-      chmod +x $KOKORO_GFILE_DIR/linux_amd64/flakybot
-      $KOKORO_GFILE_DIR/linux_amd64/flakybot
+    echo "The current head is: "
+    echo $(git rev-parse --verify HEAD)
+    echo "--- IMPORTANT IMPORTANT IMPORTANT ---"
+    # move back the test runner implementation if there's no file.
+    if [ ! -f .kokoro/test-samples-impl.sh ]; then
+	cp "${TMPDIR}/test-samples-impl.sh" .kokoro/test-samples-impl.sh
     fi
+fi
 
-    if [[ $EXIT -ne 0 ]]; then
-      RTN=1
-      echo -e "\n Testing failed: Nox returned a non-zero exit code. \n"
-    else
-      echo -e "\n Testing completed.\n"
-    fi
-
-done
-cd "$ROOT"
-
-# Workaround for Kokoro permissions issue: delete secrets
-rm testing/{test-env.sh,client-secrets.json,service-account.json}
-
-exit "$RTN"
+exec .kokoro/test-samples-impl.sh