public virtual bool ShouldScaleHttpFunction(HostingInfo hostingInfo)
{
// only main site
if (hostingInfo.HostNameType != HostNameType.Standard)
{
return(false);
}
// TODO, suwatch: support client certificate
if (hostingInfo.ClientCertEnabled)
{
return(false);
}
// white list or scm site
if (hostingInfo.NeedsPlatformAuth)
{
return(false);
}
// consumption plan
if (hostingInfo.ComputeMode != ComputeMode.Dynamic)
{
return(false);
}
// http trigger exists
return(hostingInfo.HasHttpTrigger.GetValueOrDefault());
}
public virtual bool TryValidateWorkerToken(HostingInfo hostingInfo, string workerToken, out WorkerAuthorizationToken token)
{
try
{
WorkerAuthorizationToken result;
if (_validatedTokenCaches.TryGetValue(workerToken, out result))
{
token = result;
return(true);
}
result = new WorkerAuthorizationToken(workerToken);
string failureDetails;
if (SecurityManager.Default.TryValidateToken(result, out failureDetails) && string.Equals(result.SiteName, hostingInfo.SiteName))
{
_validatedTokenCaches.Add(workerToken, result);
token = result;
return(true);
}
throw new InvalidOperationException(string.Format("Token validation failed. {0}", failureDetails));
}
catch (Exception)
{
// TODO, suwatch: tracing
}
token = null;
return(false);
}
public virtual bool TryGetWorkers(HostingInfo hostingInfo, out string[] workers)
{
workers = null;
if (string.IsNullOrEmpty(hostingInfo.ServerListOrError))
{
return(false);
}
// make sure ServerListOrError is ipAddress
if (hostingInfo.ServerListOrError[0] < '1' || hostingInfo.ServerListOrError[0] > '9')
{
return(false);
}
workers = hostingInfo.ServerListOrError.Split(',');
return(true);
}
void IProxyPeer.SubscribeHosting(HostingInfo info)
{
Channel.SubscribeHosting(info);
}
public async Task <HttpScaleInfo> OnBeginRequest(HostingInfo hostingInfo, string workerToken)
{
if (hostingInfo == null)
{
return(null);
}
if (_environment.DynamicComputeHttpScaleMaxFrontEndsPerSite <= 0)
{
return(null);
}
if (!ShouldScaleHttpFunction(hostingInfo))
{
return(null);
}
string[] workers;
if (!TryGetWorkers(hostingInfo, out workers))
{
return(null);
}
WorkerAuthorizationToken token = null;
if (!string.IsNullOrEmpty(workerToken) && !TryValidateWorkerToken(hostingInfo, workerToken, out token))
{
return(null);
}
if (token == null)
{
var forwardFrontEnd = GetForwardFrontEnd(hostingInfo.SiteName, _environment);
// do not forward, if forward FE is current
if (forwardFrontEnd == _environment.CurrentFrontEnd)
{
// worker selection
var requestId = NextHttpScaleRequestId(hostingInfo.SiteName);
var selected = await _manager.DispatchRequestAsync(requestId, hostingInfo.SiteName, hostingInfo.DefaultHostName, workers);
var info = new HttpScaleInfo();
info.RequestId = string.Format("{0}/{1}", requestId, selected);
info.HostingInfo = new HostingInfo(hostingInfo);
info.HostingInfo.ServerListOrError = selected;
// for newly added worker, create WorkerAuthorizationToken
if (!workers.Any(w => w == selected))
{
info.HostingInfo.Token = CreateWorkerToken(selected, hostingInfo.SiteName);
}
return(info);
}
else
{
var info = new HttpScaleInfo();
// TODO, suwatch: sampling tracking FE organic health
// info.RequestId = forwardFrontEnd;
info.ForwardFrontEnd = forwardFrontEnd;
info.HostingInfo = new HostingInfo(hostingInfo);
info.HostingInfo.ServerListOrError = forwardFrontEnd;
return(info);
}
}
else
{
// this is forwarded requests
var requestId = NextHttpScaleRequestId(hostingInfo.SiteName);
var selected = await _manager.DispatchRequestAsync(requestId, hostingInfo.SiteName, hostingInfo.DefaultHostName, workers.Length >= token.Workers.Length?workers : token.Workers);
var info = new HttpScaleInfo();
info.RequestId = string.Format("{0}/{1}", requestId, selected);
info.HostingInfo = new HostingInfo(hostingInfo);
info.HostingInfo.ServerListOrError = selected;
// for newly added worker, create WorkerAuthorizationToken
if (!workers.Any(w => w == selected))
{
if (token.Workers.Any(w => w == selected))
{
info.HostingInfo.Token = workerToken;
}
else
{
info.HostingInfo.Token = CreateWorkerToken(selected, hostingInfo.SiteName);
}
}
return(info);
}
}