Line data    Source code

       1             : #include "source/common/router/shadow_writer_impl.h"
       2             : 
       3             : #include <chrono>
       4             : #include <string>
       5             : 
       6             : #include "source/common/common/assert.h"
       7             : #include "source/common/http/headers.h"
       8             : 
       9             : #include "absl/strings/str_join.h"
      10             : 
      11             : namespace Envoy {
      12             : namespace Router {
      13             : 
      14             : namespace {
      15             : 
      16           0 : std::string shadowAppendedHost(absl::string_view host) {
      17           0 :   ASSERT(!host.empty());
      18             :   // Switch authority to add a shadow postfix. This allows upstream logging to
      19             :   // make more sense.
      20           0 :   auto parts = StringUtil::splitToken(host, ":");
      21           0 :   ASSERT(!parts.empty() && parts.size() <= 2);
      22           0 :   return parts.size() == 2 ? absl::StrJoin(parts, "-shadow:") : absl::StrCat(host, "-shadow");
      23           0 : }
      24             : 
      25             : } // namespace
      26             : 
      27             : void ShadowWriterImpl::shadow(const std::string& cluster, Http::RequestMessagePtr&& request,
      28           0 :                               const Http::AsyncClient::RequestOptions& options) {
      29           0 :   const auto thread_local_cluster =
      30           0 :       getClusterAndPreprocessHeadersAndOptions(cluster, request->headers(), options);
      31           0 :   if (thread_local_cluster == nullptr) {
      32           0 :     return;
      33           0 :   }
      34             :   // This is basically fire and forget. We don't handle cancelling.
      35           0 :   thread_local_cluster->httpAsyncClient().send(std::move(request), *this, options);
      36           0 : }
      37             : 
      38             : Http::AsyncClient::OngoingRequest*
      39             : ShadowWriterImpl::streamingShadow(const std::string& cluster, Http::RequestHeaderMapPtr&& headers,
      40           0 :                                   const Http::AsyncClient::RequestOptions& options) {
      41           0 :   const auto thread_local_cluster =
      42           0 :       getClusterAndPreprocessHeadersAndOptions(cluster, *headers, options);
      43           0 :   if (thread_local_cluster == nullptr) {
      44           0 :     return nullptr;
      45           0 :   }
      46           0 :   return thread_local_cluster->httpAsyncClient().startRequest(std::move(headers), *this, options);
      47           0 : }
      48             : 
      49             : Upstream::ThreadLocalCluster* ShadowWriterImpl::getClusterAndPreprocessHeadersAndOptions(
      50             :     absl::string_view cluster, Http::RequestHeaderMap& headers,
      51           0 :     const Http::AsyncClient::RequestOptions& options) {
      52             :   // It's possible that the cluster specified in the route configuration no longer exists due
      53             :   // to a CDS removal. Check that it still exists before shadowing.
      54             :   // TODO(mattklein123): Optimally we would have a stat but for now just fix the crashing issue.
      55           0 :   const auto thread_local_cluster = cm_.getThreadLocalCluster(cluster);
      56           0 :   if (thread_local_cluster == nullptr) {
      57           0 :     ENVOY_LOG(debug, "shadow cluster '{}' does not exist", cluster);
      58           0 :     return nullptr;
      59           0 :   }
      60             : 
      61           0 :   headers.setHost(shadowAppendedHost(headers.getHostValue()));
      62             : 
      63           0 :   const_cast<Http::AsyncClient::RequestOptions&>(options).setIsShadow(true);
      64           0 :   return thread_local_cluster;
      65           0 : }
      66             : 
      67             : } // namespace Router
      68             : } // namespace Envoy