Fill in the script to grab example snippets from GCS buckets. (#5242)

scripts/grab_examples.sh

@@ -14,6 +14,33 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# PLACEHOLDER
+# This script copies test snippets from documentation tests in the istio/istio repo.
+# These snippets are put into the examples directory and referenced from markdown files
+# throughout the site.
 
-gsutil -m rsync -r gs://istio-prow/pr-logs/pull/istio_istio/18015/integ-istioio-k8s-tests_istio/427/artifacts/security-690d44c99a924fefb88bca/TestAuthorizationForHTTPServices snips
+SNIPPET_REPO=https://github.com/istio/istio
+SNIPPET_BRANCH=master
+
+rm -fr examples/*.snippets.txt
+
+echo Cloning ${SNIPPET_REPO}@${SNIPPET_BRANCH}
+
+WORK_DIR="$(mktemp -d)"
+mkdir -p "${WORK_DIR}"
+git clone -q -b "${SNIPPET_BRANCH}" "${SNIPPET_REPO}" "${WORK_DIR}"
+COMMITS=$(git --git-dir="${WORK_DIR}/.git" log --oneline --no-abbrev-commit | cut -d " " -f 1)
+rm -fr "${WORK_DIR}"
+
+echo "Querying for snippets"
+
+# iterate through all the commits for the repo until we find one that has the needed artifacts
+# in gcs
+for COMMIT in $COMMITS; do
+    if gsutil -m cp "gs://istio-snippets/${COMMIT}/*.txt" examples; then
+        echo "Example snippets updated"
+        exit 0
+    fi
+done
+
+echo "Unable to download example snippets"
+exit 1