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prefanatickevmoo
prefanatic
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kevmoo
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feat(gcp): current region methods
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-57
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5 files changed

+199
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‎gcp/lib/gcp.dart

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@@ -29,5 +29,6 @@ export 'src/logging.dart'
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cloudLoggingMiddleware,
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createLoggingMiddleware,
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currentLogger;
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export 'src/metadata.dart' show MetadataValue;
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export 'src/serve.dart' show listenPort, serveHandler;
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export 'src/terminate.dart' show waitForTerminate;

‎gcp/lib/src/gcp_project.dart

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@@ -12,26 +12,16 @@
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// See the License for the specific language governing permissions and
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// limitations under the License.
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import 'dart:io';
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import 'package:http/http.dart' as http;
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import 'bad_configuration_exception.dart';
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import 'metadata.dart';
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/// A convenience wrapper that first tries [projectIdFromEnvironment]
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/// then (if the value is `null`) tries [projectIdFromMetadataServer]
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///
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/// Like [projectIdFromMetadataServer], if no value is found, a
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/// [BadConfigurationException] is thrown.
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Future<String> computeProjectId() async {
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final localValue = projectIdFromEnvironment();
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if (localValue != null) {
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return localValue;
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}
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final result = await projectIdFromMetadataServer();
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return result;
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}
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Future<String> computeProjectId() =>
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MetadataValue.project.fromEnvironmentOrMetadata();
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/// Returns the
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/// [Project ID](https://cloud.google.com/resource-manager/docs/creating-managing-projects#identifying_projects)
@@ -41,14 +31,7 @@ Future<String> computeProjectId() async {
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/// The list is checked in order. This is useful for local development.
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///
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/// If no matching variable is found, `null` is returned.
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String? projectIdFromEnvironment() {
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for (var envKey in gcpProjectIdEnvironmentVariables) {
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final value = Platform.environment[envKey];
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if (value != null) return value;
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}
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return null;
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}
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String? projectIdFromEnvironment() => MetadataValue.project.fromEnvironment();
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/// Returns a [Future] that completes with the
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/// [Project ID](https://cloud.google.com/resource-manager/docs/creating-managing-projects#identifying_projects)
@@ -57,36 +40,8 @@ String? projectIdFromEnvironment() {
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///
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/// If the metadata server cannot be contacted, a [BadConfigurationException] is
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/// thrown.
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Future<String> projectIdFromMetadataServer() async {
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const host = 'http://metadata.google.internal/';
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final url = Uri.parse('$host/computeMetadata/v1/project/project-id');
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try {
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final response = await http.get(
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url,
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headers: {'Metadata-Flavor': 'Google'},
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);
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if (response.statusCode != 200) {
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throw HttpException(
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'${response.body} (${response.statusCode})',
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uri: url,
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);
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}
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return response.body;
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} on SocketException catch (e) {
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throw BadConfigurationException(
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'''
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Could not connect to $host.
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If not running on Google Cloud, one of these environment variables must be set
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to the target Google Project ID:
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${gcpProjectIdEnvironmentVariables.join('\n')}
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''',
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details: e.toString(),
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);
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}
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}
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Future<String> projectIdFromMetadataServer() =>
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MetadataValue.project.fromMetadataServer();
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/// A set of typical environment variables that are likely to represent the
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/// current Google Cloud project ID.
@@ -98,9 +53,5 @@ ${gcpProjectIdEnvironmentVariables.join('\n')}
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///
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/// Note: these are ordered starting from the most current/canonical to least.
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/// (At least as could be determined at the time of writing.)
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const gcpProjectIdEnvironmentVariables = {
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'GCP_PROJECT',
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'GCLOUD_PROJECT',
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'CLOUDSDK_CORE_PROJECT',
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'GOOGLE_CLOUD_PROJECT',
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};
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Set<String> get gcpProjectIdEnvironmentVariables =>
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MetadataValue.project.environmentValues;

‎gcp/lib/src/metadata.dart

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Original file line numberDiff line numberDiff line change
@@ -0,0 +1,138 @@
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// Copyright 2022 Google LLC
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
10+
// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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15+
import 'dart:io';
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import 'package:http/http.dart' as http;
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import 'bad_configuration_exception.dart';
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enum MetadataValue {
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/// A set of typical environment variables that are likely to represent the
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/// current Google Cloud instance region.
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///
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/// For context, see:
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/// * https://cloud.google.com/functions/docs/env-var
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/// * https://cloud.google.com/compute/docs/gcloud-compute#default_project
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/// * https://github.com/GoogleContainerTools/gcp-auth-webhook/blob/08136ca171fe5713cc70ef822c911fbd3a1707f5/server.go#L38-L44
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///
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/// Note: these are ordered starting from the most current/canonical to least.
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/// (At least as could be determined at the time of writing.)
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project(
33+
path: 'project/project-id',
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environmentValues: {
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'GCP_PROJECT',
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'GCLOUD_PROJECT',
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'CLOUDSDK_CORE_PROJECT',
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'GOOGLE_CLOUD_PROJECT',
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},
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),
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42+
/// A set of typical environment variables that are likely to represent the
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/// current Google Cloud instance region.
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///
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/// For context, see:
46+
/// * https://cloud.google.com/functions/docs/env-var
47+
/// * https://cloud.google.com/compute/docs/gcloud-compute#default_project
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/// * https://github.com/GoogleContainerTools/gcp-auth-webhook/blob/08136ca171fe5713cc70ef822c911fbd3a1707f5/server.go#L38-L44
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///
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/// Note: these are ordered starting from the most current/canonical to least.
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/// (At least as could be determined at the time of writing.)
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region(
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path: 'instance/region',
54+
environmentValues: {
55+
'FUNCTION_REGION',
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'CLOUDSDK_COMPUTE_REGION',
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},
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);
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const MetadataValue({
61+
required this.path,
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required this.environmentValues,
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});
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final String path;
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final Set<String> environmentValues;
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/// A convenience wrapper that first tries [fromEnvironment]
70+
/// then (if the value is `null`) tries [fromMetadataServer]
71+
///
72+
/// Like [fromMetadataServer], if no value is found, a
73+
/// [BadConfigurationException] is thrown.
74+
Future<String> fromEnvironmentOrMetadata() async {
75+
final localValue = fromEnvironment();
76+
if (localValue != null) {
77+
return localValue;
78+
}
79+
final result = await fromMetadataServer();
80+
81+
return result;
82+
}
83+
84+
/// Returns the
85+
/// [Region](https://cloud.google.com/compute/docs/regions-zones#identifying_a_region_or_zone)
86+
/// for the current instance by checking the environment variables in
87+
/// [environmentValues].
88+
///
89+
/// The list is checked in order. This is useful for local development.
90+
///
91+
/// If no matching variable is found, `null` is returned.
92+
String? fromEnvironment() {
93+
for (var envKey in environmentValues) {
94+
final value = Platform.environment[envKey];
95+
if (value != null) return value;
96+
}
97+
98+
return null;
99+
}
100+
101+
/// Returns a [Future] that completes with the
102+
/// [Region](https://cloud.google.com/compute/docs/regions-zones#identifying_a_region_or_zone)
103+
/// for the current instance by checking
104+
/// [instance metadata](https://cloud.google.com/compute/docs/metadata/default-metadata-values#vm_instance_metadata).
105+
///
106+
/// If the metadata server cannot be contacted, a [BadConfigurationException]
107+
/// is thrown.
108+
Future<String> fromMetadataServer() async {
109+
const host = 'http://metadata.google.internal/';
110+
final url = Uri.parse('$host/computeMetadata/v1/$path');
111+
112+
try {
113+
final response = await http.get(
114+
url,
115+
headers: {'Metadata-Flavor': 'Google'},
116+
);
117+
118+
if (response.statusCode != 200) {
119+
throw HttpException(
120+
'${response.body} (${response.statusCode})',
121+
uri: url,
122+
);
123+
}
124+
125+
return response.body;
126+
} on SocketException catch (e) {
127+
throw BadConfigurationException(
128+
'''
129+
Could not connect to $host.
130+
If not running on Google Cloud, one of these environment variables must be set
131+
to the target region:
132+
${environmentValues.join('\n')}
133+
''',
134+
details: e.toString(),
135+
);
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}
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}
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}

‎gcp/test/gcp_test.dart

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@@ -131,6 +131,40 @@ void main() {
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});
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},
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);
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135+
group('currentRegion', () {
136+
const regionPrint = 'test/src/region_print.dart';
137+
138+
test('not environment', () async {
139+
final proc = await _run(regionPrint);
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141+
final errorOut = await proc.stderrStream().toList();
142+
143+
await expectLater(
144+
errorOut,
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containsAll(MetadataValue.region.environmentValues),
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);
147+
await expectLater(proc.stdout, emitsDone);
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149+
await proc.shouldExit(255);
150+
});
151+
152+
test('environment set', () async {
153+
final proc = await _run(
154+
regionPrint,
155+
environment: {
156+
MetadataValue.region.environmentValues.first: 'us-central1',
157+
},
158+
);
159+
160+
await expectLater(proc.stdout, emits('us-central1'));
161+
await expectLater(proc.stderr, emitsDone);
162+
163+
await proc.shouldExit(0);
164+
});
165+
166+
// TODO: worth emulating the metadata server?
167+
});
134168
}
135169

136170
Future<TestProcess> _run(

‎gcp/test/src/region_print.dart

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1+
// Copyright 2022 Google LLC
2+
//
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// Licensed under the Apache License, Version 2.0 (the "License");
4+
// you may not use this file except in compliance with the License.
5+
// You may obtain a copy of the License at
6+
//
7+
// http://www.apache.org/licenses/LICENSE-2.0
8+
//
9+
// Unless required by applicable law or agreed to in writing, software
10+
// distributed under the License is distributed on an "AS IS" BASIS,
11+
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12+
// See the License for the specific language governing permissions and
13+
// limitations under the License.
14+
import 'package:gcp/gcp.dart';
15+
16+
Future<void> main() async {
17+
print(await MetadataValue.region.fromEnvironmentOrMetadata());
18+
}

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