Setting GOOGLE_APPLICATION_CREDENTIALS for an MVC site hosted on azure - asp.net-mvc

Question

Title says it all pretty much.
I tried uploading the json file to azure storage and referenced it's url when setting the GOOGLE_APPLICATION_CREDENTIALS environment variable under app settings, but when remotely debugging the site, apparently the url/directory was not in an acceptable format. I can’t store the json file locally either because the website doesn’t have any idea about my C drive directories.
Where should I store this file so that I can set the GOOGLE_APPLICATION_CREDENTIALS environment variable for my azure site to the directory of the json file?

Answer 1

The ToChannelCredentials() approach does not seem to work anymore, so I come up with an other solution that works on Azure. I create a text file in the /bin folder of my Azure server with the credentials and then I point the environment variable to this file. Google Cloud API will use this for the default credentials.
string json = #"{
'type': 'service_account',
'project_id': 'xxx',
'private_key_id': 'xx',
'private_key': 'xxx',
...
}"; // this is the content of the json-credentials file from Google
// Create text file in projects bin-folder
var binDirectory = Path.GetDirectoryName(Assembly.GetCallingAssembly().CodeBase);
string fullPath = Path.Combine(binDirectory, "credentials.json").Replace("file:\\","");
using (StreamWriter outputFile = new StreamWriter(fullPath, false)) {
outputFile.WriteLine(json);
}
// Set environment variabel to the full file path
Environment.SetEnvironmentVariable("GOOGLE_APPLICATION_CREDENTIALS", fullPath);
// Now you can call the service and it will pick up your credentials
TranslationServiceClient client = TranslationServiceClient.Create();

Answer 2

If anyone is wondering how to handle the Google's credentials smoothly in .Net applications instead of strange way of using the file on server, this is how I solved it for Translation Service. Other services must follow same principle:
store the content of the Google credentials json file as an environment variable in settings.json/azure configuration for your app (using ' ' instead of " " for inner text):
"GOOGLE_APPLICATION_CREDENTIALS": "{'type': 'service_account','project_id': ...}"
create and return the client:
var credential = GoogleCredential.FromJson(Environment.GetEnvironmentVariable("GOOGLE_APPLICATION_CREDENTIALS"));
var channelCredentials = credential.ToChannelCredentials();
var channel = new Channel(TranslationServiceClient.DefaultEndpoint.ToString(), channelCredentials);
return TranslationServiceClient.Create(channel);
Took a while for me to figure it our. Hope it helps.

Answer 3

I use the .json file in my local environment (because of environment variable length limit in Windows) and on Azure I use an "Application setting" to set an environment variable. This code handles both cases:
string? json;
var filename = Environment.GetEnvironmentVariable("GOOGLE_APPLICATION_CREDENTIALS");
if (filename != null)
{
json = System.IO.File.ReadAllText(filename);
}
else
{
json = Environment.GetEnvironmentVariable("GOOGLE_APPLICATION_CREDENTIALS_STRING");
if (json == null)
{
throw new Exception(
"GOOGLE_APPLICATION_CREDENTIALS_STRING environment variable with JSON is not set");
}
}
var credential = GoogleCredential.FromJson(json).ToChannelCredentials();
var grpcChannel = new Channel("firestore.googleapis.com", credential);
var grcpClient = new Firestore.FirestoreClient(grpcChannel);
var firestoreClient = new FirestoreClientImpl(grcpClient, FirestoreSettings.GetDefault());
return await FirestoreDb.CreateAsync(FirebaseProjectId, firestoreClient);

Answer 4

Was looking how to set the "GOOGLE_APPLICATION_CREDENTIALS" in Azure App Service. The answers here didn't help me. My solution is very simple without any code change.
In the configuration of the app service go to the Path Mappings
Add a New Azure Storage Mount. eg /mounts/config
Add the credentials.json file to the file share
In the application settings, add the GOOGLE_APPLICATION_CREDENTIALS and set the value to: /mounts/config/credentials.json
That is all.

Answer 5

In the azure app on the azure portal go to application settings and add the credentials under application settings tab
Then you can reference them in your code as they were in your web.config file.