public async Task Run([TimerTrigger("0 */5 * * * *")] TimerInfo myTimer, ILogger log)
{
log.LogInformation($"C# Timer trigger function executed at: {DateTime.Now}");
if (myTimer.IsPastDue)
{
log.LogInformation("Skipping past due invocation, waiting for next scheduled run");
return;
}
var subscriptions = await _msalAccountActivityStore.GetSubscriptionActivities();
foreach (var subscription in subscriptions)
{
// Get the most recently updated msal account information for this subscription
var account = await _msalAccountActivityStore.GetMsalAccountActivityForSubscription(subscription.SubscriptionId);
if (account != null)
{
// Configure the confidential client to get an access token for the needed resource
var app = ConfidentialClientApplicationBuilder.Create(_config.GetValue <string>("AzureAd:ClientId"))
.WithClientSecret(_config.GetValue <string>("AzureAd:ClientSecret"))
.WithAuthority($"{_config.GetValue<string>("AzureAd:Instance")}{_config.GetValue<string>("AzureAd:TenantId")}")
.Build();
// Initialize the MSAL cache for the specific account
var msalCache = new BackgroundWorkerTokenCacheAdapter(account.AccountCacheKey,
_serviceProvider.GetService <IDistributedCache>(),
_serviceProvider.GetService <ILogger <MsalDistributedTokenCacheAdapter> >(),
_serviceProvider.GetService <IOptions <MsalDistributedTokenCacheAdapterOptions> >());
await msalCache.InitializeAsync(app.UserTokenCache);
// Prepare an MsalAccount instance representing the user we want to get a token for
var hydratedAccount = new MsalAccount
{
HomeAccountId = new AccountId(
account.AccountIdentifier,
account.AccountObjectId,
account.AccountTenantId)
};
try
{
// Use the confidential MSAL client to get a token for the user we need to impersonate
var result = await app.AcquireTokenSilent(Constants.BasePermissionScopes, hydratedAccount)
.ExecuteAsync()
.ConfigureAwait(false);
// Configure the Graph SDK to use an auth provider that takes the token we've just requested
var authenticationProvider = new DelegateAuthenticationProvider(
(requestMessage) =>
{
requestMessage.Headers.Authorization = new AuthenticationHeaderValue(CoreConstants.Headers.Bearer, result.AccessToken);
return(Task.FromResult(0));
});
var graphClient = new GraphServiceClient(authenticationProvider);
// Add/renew the subscriptions
await SubscriptionManagement.ManageSubscription(subscription, account.AccountObjectId, account.AccountTenantId, account.UserPrincipalName,
_config, _msalAccountActivityStore, graphClient, _msalTokenCacheProvider);
}
catch (MsalUiRequiredException ex)
{
/*
* If MsalUiRequiredException is thrown for an account, it means that a user interaction is required
* thus the background worker wont be able to acquire a token silently for it.
* The user of that account will have to access the web app to perform this interaction.
* Examples that could cause this: MFA requirement, token expired or revoked, token cache deleted, etc
*/
await _msalAccountActivityStore.HandleIntegratedTokenAcquisitionFailure(account);
log.LogError($"Could not acquire token for account {account.UserPrincipalName}.");
log.LogError($"Error: {ex.Message}");
}
catch (Exception ex)
{
throw ex;
}
}
}
}
public async Task Run([QueueTrigger(Constants.OneDriveFileNotificationsQueue)] string myQueueItem, ILogger log)
{
log.LogInformation($"C# Queue trigger function processed: {myQueueItem}");
var notification = JsonSerializer.Deserialize <ChangeNotification>(myQueueItem);
// Get the most recently updated msal account information for this subscription
var account = await _msalAccountActivityStore.GetMsalAccountActivityForSubscription(notification.SubscriptionId);
if (account != null)
{
// Configure the confidential client to get an access token for the needed resource
var app = ConfidentialClientApplicationBuilder.Create(_config.GetValue <string>("AzureAd:ClientId"))
.WithClientSecret(_config.GetValue <string>("AzureAd:ClientSecret"))
.WithAuthority($"{_config.GetValue<string>("AzureAd:Instance")}{_config.GetValue<string>("AzureAd:TenantId")}")
.Build();
// Initialize the MSAL cache for the specific account
var msalCache = new BackgroundWorkerTokenCacheAdapter(account.AccountCacheKey,
_serviceProvider.GetService <IDistributedCache>(),
_serviceProvider.GetService <ILogger <MsalDistributedTokenCacheAdapter> >(),
_serviceProvider.GetService <IOptions <MsalDistributedTokenCacheAdapterOptions> >());
await msalCache.InitializeAsync(app.UserTokenCache);
// Prepare an MsalAccount instance representing the user we want to get a token for
var hydratedAccount = new MsalAccount
{
HomeAccountId = new AccountId(
account.AccountIdentifier,
account.AccountObjectId,
account.AccountTenantId)
};
try
{
// Use the confidential MSAL client to get a token for the user we need to impersonate
var result = await app.AcquireTokenSilent(Constants.BasePermissionScopes, hydratedAccount)
.ExecuteAsync()
.ConfigureAwait(false);
//log.LogInformation($"Token acquired: {result.AccessToken}");
// Configure the Graph SDK to use an auth provider that takes the token we've just requested
var authenticationProvider = new DelegateAuthenticationProvider(
(requestMessage) =>
{
requestMessage.Headers.Authorization = new AuthenticationHeaderValue(CoreConstants.Headers.Bearer, result.AccessToken);
return(Task.FromResult(0));
});
var graphClient = new GraphServiceClient(authenticationProvider);
// Retrieve the last used subscription activity information for this user+subscription
var subscriptionActivity = await _msalAccountActivityStore.GetSubscriptionActivityForUserSubscription(account.AccountObjectId, account.AccountTenantId, account.UserPrincipalName, notification.SubscriptionId);
// Make graph call on behalf of the user: do the delta query providing the last used change token so only new changes are returned
IDriveItemDeltaCollectionPage deltaCollection = await graphClient.Me.Drive.Root.Delta(subscriptionActivity.LastChangeToken).Request().GetAsync();
bool morePagesAvailable = false;
do
{
// If there is a NextPageRequest, there are more pages
morePagesAvailable = deltaCollection.NextPageRequest != null;
foreach (var driveItem in deltaCollection.CurrentPage)
{
await ProcessDriveItemChanges(driveItem, log);
}
if (morePagesAvailable)
{
// Get the next page of results
deltaCollection = await deltaCollection.NextPageRequest.GetAsync();
}
}while (morePagesAvailable);
// Get the last used change token
var deltaLink = deltaCollection.AdditionalData["@odata.deltaLink"];
if (!string.IsNullOrEmpty(deltaLink.ToString()))
{
var token = GetChangeTokenFromUrl(deltaLink.ToString());
subscriptionActivity.LastChangeToken = token;
}
// Persist back the last used change token
await _msalAccountActivityStore.UpsertSubscriptionActivity(subscriptionActivity);
}
catch (MsalUiRequiredException ex)
{
/*
* If MsalUiRequiredException is thrown for an account, it means that a user interaction is required
* thus the background worker wont be able to acquire a token silently for it.
* The user of that account will have to access the web app to perform this interaction.
* Examples that could cause this: MFA requirement, token expired or revoked, token cache deleted, etc
*/
await _msalAccountActivityStore.HandleIntegratedTokenAcquisitionFailure(account);
log.LogError($"Could not acquire token for account {account.UserPrincipalName}.");
log.LogError($"Error: {ex.Message}");
}
catch (Exception ex)
{
throw ex;
}
}
}