Disable Azure Function on a particular condition - azure

Question

We have a azure function where we are calling few API's. its an eventhub trigger function. we have a scenario where the api which we are calling goes into schedule maintenance very often. we want to build a re try mechanism where we are re trying for x number of times and on failure we want to disable the function on runtime. is there a way we can do that in the function app itself?

Answer 1

Thank you Melissa and Ian Kemp. Posting your suggestions as answer to help other community members.
Use the below code to disable the Azure Function
public class FunctionsHelper
{
private readonly ClientSecretCredential _tokenCredential;
private readonly HttpClient _httpClient;
public FunctionsHelper(string tenantId, string clientId, string clientSecret, string subscriptionId, string resourceGroup, string functionAppName)
{
var baseUrl =
$"https://management.azure.com/subscriptions/{subscriptionId}/resourceGroups/{resourceGroup}/providers/Microsoft.Web/sites/{functionAppName}/";
var httpClient = new HttpClient
{
BaseAddress = new Uri(baseUrl)
};
_httpClient = httpClient;
_tokenCredential = new ClientSecretCredential(tenantId, clientId, clientSecret);
}
private async Task SetAuthHeader()
{
var accessToken = await GetAccessToken();
_httpClient.DefaultRequestHeaders.Authorization = AuthenticationHeaderValue.Parse($"Bearer {accessToken}");
}
private async Task<string> GetAccessToken()
{
return (await _tokenCredential.GetTokenAsync(
new TokenRequestContext(new[] {"https://management.azure.com/.default"}))).Token;
}
public async Task StopFunction(string functionName)
{
await SetFunctionState(functionName, isDisabled: true);
}
public async Task StartFunction(string functionName)
{
await SetFunctionState(functionName, isDisabled: false);
}
private async Task SetFunctionState(string functionName, bool isDisabled)
{
await SetAuthHeader();
var appSettings = await GetAppSettings();
appSettings.properties[$"AzureWebJobs.{functionName}.Disabled"] = isDisabled ? "1" : "0";
var payloadJson = JsonConvert.SerializeObject(new
{
kind = "<class 'str'>", appSettings.properties
});
var stringContent = new StringContent(payloadJson, Encoding.UTF8, "application/json");
await _httpClient.PutAsync("config/appsettings?api-version=2019-08-01", stringContent);
}
private async Task<AppSettings> GetAppSettings()
{
var res = await _httpClient.PostAsync("config/appsettings/list?api-version=2019-08-01", null);
var content = await res.Content.ReadAsStringAsync();
return JsonConvert.DeserializeObject<AppSettings>(content);
}
}
internal class AppSettings
{
public Dictionary<string, string> properties { get; set; }
}
Check the SO for further information.