public async Task Invoke(HttpContext context)
{
var excMessage = "";
try
{
using (var requestReader = new StreamReader(context.Request.Body))
{
//mapping headers and query string from request
var requestHeaders = context.Request.Headers.Select(p => new KeyValuePair <string, string>(p.Key, p.Value));
var requestParameters = context.Request.Query.Select(p => new KeyValuePair <string, string>(p.Key, p.Value));
//mapping request payload
var requestPayload = new ASPNetLambdaProxyRequestDTO()
{
Headers = new Dictionary <string, string>(requestHeaders),
Resource = "/{proxy+}",
HttpMethod = context.Request.Method,
Path = context.Request.Path.Value,
Body = await requestReader.ReadToEndAsync().ConfigureAwait(false),
QueryStringParameters = new Dictionary <string, string>(requestParameters)
};
requestHeaders = null;
requestParameters = null;
//invoking lambda
var invokeRequest = new InvokeRequest()
{
FunctionName = _config.AWS.Lambda.FunctionName,
InvocationType = InvocationType.RequestResponse,
Payload = JsonConvert.SerializeObject(requestPayload)
};
var integrationWatch = new Stopwatch();
integrationWatch.Start();
var invokeResponse = await _lambdaClient
.ExecuteWithNoExceptionsAsync(c => c.InvokeAsync(invokeRequest))
.ConfigureAwait(false);
integrationWatch.Stop();
//executing pipeline
invokeRequest = null;
await _next.Invoke(context).ConfigureAwait(false);
//mapping lambda response
var responsePayload = (ASPNetLambdaProxyResponseDTO)null;
using (var responseReader = new StreamReader(invokeResponse.Payload))
{
responsePayload = JsonConvert.DeserializeObject <ASPNetLambdaProxyResponseDTO>(responseReader.ReadToEnd());
}
responsePayload.Headers.Add("X-Proxy-Time", integrationWatch.ElapsedMilliseconds.ToString());
integrationWatch = null;
//loading response content
foreach (var pair in responsePayload.Headers)
{
if (context.Response.Headers.ContainsKey(pair.Key))
{
context.Response.Headers[pair.Key] = pair.Value;
}
else
{
context.Response.Headers.Add(pair.Key, pair.Value);
}
}
using (var responseWriter = new StreamWriter(context.Response.Body))
{
context.Response.StatusCode = (int)invokeResponse.HttpStatusCode;
await responseWriter.WriteAsync(responsePayload.Body).ConfigureAwait(false);
}
invokeResponse = null;
responsePayload = null;
}
}
catch (Exception e)
{
context.Response.StatusCode = 500;
excMessage = e.Message;
}
finally
{
if (string.IsNullOrWhiteSpace(excMessage) == false)
{
await context.Response.WriteAsync(excMessage).ConfigureAwait(false);
}
}
}
