| # |
| # Licensed to the Apache Software Foundation (ASF) under one or more |
| # contributor license agreements. See the NOTICE file distributed with |
| # this work for additional information regarding copyright ownership. |
| # The ASF licenses this file to You 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. |
| # |
| |
| """Fetches GCE metadata if the calling process is running on a GCE VM.""" |
| |
| # pytype: skip-file |
| |
| import requests |
| |
| BASE_METADATA_URL = "http://metadata/computeMetadata/v1/" |
| |
| |
| def _fetch_metadata(key): |
| try: |
| headers = {"Metadata-Flavor": "Google"} |
| uri = BASE_METADATA_URL + key |
| resp = requests.get(uri, headers=headers, timeout=5) # 5 seconds. |
| if resp.status_code == 200: |
| return resp.text |
| except requests.exceptions.RequestException: |
| # Silently fail, may mean its running on a non DataflowRunner, |
| # in which case it's prefectly normal. |
| pass |
| return "" |
| |
| |
| def _fetch_custom_gce_metadata(customMetadataKey): |
| return _fetch_metadata("instance/attributes/" + customMetadataKey) |
| |
| |
| def fetch_dataflow_job_id(): |
| return _fetch_custom_gce_metadata("job_id") |