diff --git a/.kokoro/build.sh b/.kokoro/build.sh
index 3ce87f3..3a63e98 100755
--- a/.kokoro/build.sh
+++ b/.kokoro/build.sh
@@ -36,4 +36,10 @@
 python3.6 -m pip install --upgrade --quiet nox
 python3.6 -m nox --version
 
-python3.6 -m nox
+# If NOX_SESSION is set, it only runs the specified session,
+# otherwise run all the sessions.
+if [[ -n "${NOX_SESSION:-}" ]]; then
+    python3.6 -m nox -s "${NOX_SESSION:-}"
+else
+    python3.6 -m nox
+fi
diff --git a/.kokoro/docs/common.cfg b/.kokoro/docs/common.cfg
index d6b4967..24c8c89 100644
--- a/.kokoro/docs/common.cfg
+++ b/.kokoro/docs/common.cfg
@@ -30,7 +30,7 @@
 
 env_vars: {
     key: "V2_STAGING_BUCKET"
-    value: "docs-staging-v2-staging"
+    value: "docs-staging-v2"
 }
 
 # It will upload the docker image after successful builds.
diff --git a/.kokoro/populate-secrets.sh b/.kokoro/populate-secrets.sh
new file mode 100755
index 0000000..f525142
--- /dev/null
+++ b/.kokoro/populate-secrets.sh
@@ -0,0 +1,43 @@
+#!/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
+#
+#      http://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.
+
+set -eo pipefail
+
+function now { date +"%Y-%m-%d %H:%M:%S" | tr -d '\n' ;}
+function msg { println "$*" >&2 ;}
+function println { printf '%s\n' "$(now) $*" ;}
+
+
+# Populates requested secrets set in SECRET_MANAGER_KEYS from service account:
+# kokoro-trampoline@cloud-devrel-kokoro-resources.iam.gserviceaccount.com
+SECRET_LOCATION="${KOKORO_GFILE_DIR}/secret_manager"
+msg "Creating folder on disk for secrets: ${SECRET_LOCATION}"
+mkdir -p ${SECRET_LOCATION}
+for key in $(echo ${SECRET_MANAGER_KEYS} | sed "s/,/ /g")
+do
+  msg "Retrieving secret ${key}"
+  docker run --entrypoint=gcloud \
+    --volume=${KOKORO_GFILE_DIR}:${KOKORO_GFILE_DIR} \
+    gcr.io/google.com/cloudsdktool/cloud-sdk \
+    secrets versions access latest \
+    --project cloud-devrel-kokoro-resources \
+    --secret ${key} > \
+    "${SECRET_LOCATION}/${key}"
+  if [[ $? == 0 ]]; then
+    msg "Secret written to ${SECRET_LOCATION}/${key}"
+  else
+    msg "Error retrieving secret ${key}"
+  fi
+done
diff --git a/.kokoro/release/common.cfg b/.kokoro/release/common.cfg
index b2088d0..b56ca90 100644
--- a/.kokoro/release/common.cfg
+++ b/.kokoro/release/common.cfg
@@ -23,42 +23,18 @@
     value: "github/google-auth-library-python/.kokoro/release.sh"
 }
 
-# Fetch the token needed for reporting release status to GitHub
-before_action {
-  fetch_keystore {
-    keystore_resource {
-      keystore_config_id: 73713
-      keyname: "yoshi-automation-github-key"
-    }
-  }
+# Fetch PyPI password	
+before_action {	
+  fetch_keystore {	
+    keystore_resource {	
+      keystore_config_id: 73713	
+      keyname: "google_cloud_pypi_password"	
+    }	
+  }	
 }
 
-# Fetch PyPI password
-before_action {
-  fetch_keystore {
-    keystore_resource {
-      keystore_config_id: 73713
-      keyname: "google_cloud_pypi_password"
-    }
-  }
-}
-
-# Fetch magictoken to use with Magic Github Proxy 
-before_action {
-  fetch_keystore {
-    keystore_resource {
-      keystore_config_id: 73713
-      keyname: "releasetool-magictoken"
-    }
-  }
-}
-
-# Fetch api key to use with Magic Github Proxy 
-before_action {
-  fetch_keystore {
-    keystore_resource {
-      keystore_config_id: 73713
-      keyname: "magic-github-proxy-api-key"
-    }
-  }
-}
+# Tokens needed to report release status back to GitHub
+env_vars: {
+  key: "SECRET_MANAGER_KEYS"
+  value: "releasetool-publish-reporter-app,releasetool-publish-reporter-googleapis-installation,releasetool-publish-reporter-pem"
+}
\ No newline at end of file
diff --git a/.kokoro/samples/python3.6/common.cfg b/.kokoro/samples/python3.6/common.cfg
index 792bc4b..4895c2b 100644
--- a/.kokoro/samples/python3.6/common.cfg
+++ b/.kokoro/samples/python3.6/common.cfg
@@ -13,6 +13,12 @@
     value: "py-3.6"
 }
 
+# Declare build specific Cloud project.
+env_vars: {
+    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
+    value: "python-docs-samples-tests-py36"
+}
+
 env_vars: {
     key: "TRAMPOLINE_BUILD_FILE"
     value: "github/google-auth-library-python/.kokoro/test-samples.sh"
diff --git a/.kokoro/samples/python3.7/common.cfg b/.kokoro/samples/python3.7/common.cfg
index 209f6ce..90aaef1 100644
--- a/.kokoro/samples/python3.7/common.cfg
+++ b/.kokoro/samples/python3.7/common.cfg
@@ -13,6 +13,12 @@
     value: "py-3.7"
 }
 
+# Declare build specific Cloud project.
+env_vars: {
+    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
+    value: "python-docs-samples-tests-py37"
+}
+
 env_vars: {
     key: "TRAMPOLINE_BUILD_FILE"
     value: "github/google-auth-library-python/.kokoro/test-samples.sh"
diff --git a/.kokoro/samples/python3.8/common.cfg b/.kokoro/samples/python3.8/common.cfg
index b0095da..78fd8c7 100644
--- a/.kokoro/samples/python3.8/common.cfg
+++ b/.kokoro/samples/python3.8/common.cfg
@@ -13,6 +13,12 @@
     value: "py-3.8"
 }
 
+# Declare build specific Cloud project.
+env_vars: {
+    key: "BUILD_SPECIFIC_GCLOUD_PROJECT"
+    value: "python-docs-samples-tests-py38"
+}
+
 env_vars: {
     key: "TRAMPOLINE_BUILD_FILE"
     value: "github/google-auth-library-python/.kokoro/test-samples.sh"
diff --git a/.kokoro/test-samples.sh b/.kokoro/test-samples.sh
index f4426f6..9a9de20 100755
--- a/.kokoro/test-samples.sh
+++ b/.kokoro/test-samples.sh
@@ -28,6 +28,12 @@
     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
 
@@ -101,4 +107,4 @@
 # Workaround for Kokoro permissions issue: delete secrets
 rm testing/{test-env.sh,client-secrets.json,service-account.json}
 
-exit "$RTN"
\ No newline at end of file
+exit "$RTN"
diff --git a/.kokoro/trampoline.sh b/.kokoro/trampoline.sh
index e8c4251..f39236e 100755
--- a/.kokoro/trampoline.sh
+++ b/.kokoro/trampoline.sh
@@ -15,9 +15,14 @@
 
 set -eo pipefail
 
-python3 "${KOKORO_GFILE_DIR}/trampoline_v1.py"  || ret_code=$?
+# Always run the cleanup script, regardless of the success of bouncing into
+# the container.
+function cleanup() {
+    chmod +x ${KOKORO_GFILE_DIR}/trampoline_cleanup.sh
+    ${KOKORO_GFILE_DIR}/trampoline_cleanup.sh
+    echo "cleanup";
+}
+trap cleanup EXIT
 
-chmod +x ${KOKORO_GFILE_DIR}/trampoline_cleanup.sh
-${KOKORO_GFILE_DIR}/trampoline_cleanup.sh || true
-
-exit ${ret_code}
+$(dirname $0)/populate-secrets.sh # Secret Manager secrets.
+python3 "${KOKORO_GFILE_DIR}/trampoline_v1.py"
\ No newline at end of file
diff --git a/synth.metadata b/synth.metadata
index 2563871..5e1ef9a 100644
--- a/synth.metadata
+++ b/synth.metadata
@@ -4,15 +4,51 @@
       "git": {
         "name": ".",
         "remote": "https://github.com/googleapis/google-auth-library-python.git",
-        "sha": "20f82e22b7e8c6c7fdd29e08eaf7b4cf2abdcf37"
+        "sha": "9c4200dff31986b7ff300126e9aa35d14aa84dba"
       }
     },
     {
       "git": {
         "name": "synthtool",
         "remote": "https://github.com/googleapis/synthtool.git",
-        "sha": "39b527a39f5cd56d4882b3874fc08eed4756cebe"
+        "sha": "da5c6050d13b4950c82666a81d8acd25157664ae"
       }
     }
+  ],
+  "generatedFiles": [
+    ".kokoro/build.sh",
+    ".kokoro/continuous/common.cfg",
+    ".kokoro/continuous/continuous.cfg",
+    ".kokoro/docker/docs/Dockerfile",
+    ".kokoro/docker/docs/fetch_gpg_keys.sh",
+    ".kokoro/docs/common.cfg",
+    ".kokoro/docs/docs-presubmit.cfg",
+    ".kokoro/docs/docs.cfg",
+    ".kokoro/populate-secrets.sh",
+    ".kokoro/presubmit/common.cfg",
+    ".kokoro/presubmit/presubmit.cfg",
+    ".kokoro/publish-docs.sh",
+    ".kokoro/release.sh",
+    ".kokoro/release/common.cfg",
+    ".kokoro/release/release.cfg",
+    ".kokoro/samples/lint/common.cfg",
+    ".kokoro/samples/lint/continuous.cfg",
+    ".kokoro/samples/lint/periodic.cfg",
+    ".kokoro/samples/lint/presubmit.cfg",
+    ".kokoro/samples/python3.6/common.cfg",
+    ".kokoro/samples/python3.6/continuous.cfg",
+    ".kokoro/samples/python3.6/periodic.cfg",
+    ".kokoro/samples/python3.6/presubmit.cfg",
+    ".kokoro/samples/python3.7/common.cfg",
+    ".kokoro/samples/python3.7/continuous.cfg",
+    ".kokoro/samples/python3.7/periodic.cfg",
+    ".kokoro/samples/python3.7/presubmit.cfg",
+    ".kokoro/samples/python3.8/common.cfg",
+    ".kokoro/samples/python3.8/continuous.cfg",
+    ".kokoro/samples/python3.8/periodic.cfg",
+    ".kokoro/samples/python3.8/presubmit.cfg",
+    ".kokoro/test-samples.sh",
+    ".kokoro/trampoline.sh",
+    ".kokoro/trampoline_v2.sh"
   ]
 }
\ No newline at end of file