public bool StartAssignment(HostAssignmentContext context)
{
if (!_webHostEnvironment.InStandbyMode)
{
// This is only true when specializing pinned containers.
if (!context.Environment.TryGetValue(EnvironmentSettingNames.ContainerStartContext, out string startContext))
{
_logger.LogError("Assign called while host is not in placeholder mode and start context is not present.");
return(false);
}
}
if (_environment.IsContainerReady())
{
_logger.LogError("Assign called while container is marked as specialized.");
return(false);
}
if (context.IsWarmupRequest)
{
// Based on profiling download code jit-ing holds up cold start.
// Pre-jit to avoid paying the cost later.
Task.Run(async() => await _packageDownloadHandler.Download(context.GetRunFromPkgContext()));
return(true);
}
else if (_assignmentContext == null)
{
lock (_assignmentLock)
{
if (_assignmentContext != null)
{
return(_assignmentContext.Equals(context));
}
_assignmentContext = context;
}
_logger.LogInformation($"Starting Assignment. Cloud Name: {_environment.GetCloudName()}");
// set a flag which will cause any incoming http requests to buffer
// until specialization is complete
// the host is guaranteed not to receive any requests until AFTER assign
// has been initiated, so setting this flag here is sufficient to ensure
// that any subsequent incoming requests while the assign is in progress
// will be delayed until complete
_webHostEnvironment.DelayRequests();
// start the specialization process in the background
Task.Run(async() => await Assign(context));
return(true);
}
else
{
// No lock needed here since _assignmentContext is not null when we are here
return(_assignmentContext.Equals(context));
}
}
public async Task <bool> ApplyBlobPackageContext(RunFromPackageContext pkgContext, string targetPath, bool azureFilesMounted, bool throwOnFailure = true)
{
try
{
// If Azure Files are mounted, /home will point to a shared remote dir
// So extracting to /home/site/wwwroot can interfere with other running instances
// Instead extract to localSitePackagesPath and bind to /home/site/wwwroot
// home will continue to point to azure file share
var localSitePackagesPath = azureFilesMounted
? _environment.GetEnvironmentVariableOrDefault(EnvironmentSettingNames.LocalSitePackages,
EnvironmentSettingNames.DefaultLocalSitePackagesPath)
: string.Empty;
// download zip and extract
var filePath = await _packageDownloadHandler.Download(pkgContext);
await UnpackPackage(filePath, targetPath, pkgContext, localSitePackagesPath);
string bundlePath = Path.Combine(targetPath, "worker-bundle");
if (Directory.Exists(bundlePath))
{
_logger.LogInformation("Python worker bundle detected");
}
return(true);
}
catch (Exception e)
{
_logger.LogDebug(e, nameof(ApplyBlobPackageContext));
if (throwOnFailure)
{
throw;
}
return(false);
}
}
