Use the new internal service for network connections

This is achieved by replacing the NetworkConnectionInfoServiceComm
component with the Output component.

TODO:
- Receiving messages from sensor is not fully implemented, but the
  mechanisms are already in place for it.
- NetworkStatusNotifierTest is broken.

Author: Molter73

.github/workflows/integration-test-containers.yml

@@ -48,6 +48,7 @@ jobs:
               - integration-tests/images.yml
               - integration-tests/Dockerfile
               - .github/workflows/integration-test-containers.yml
+              - collector/proto/third_party/stackrox
 
   build-test-image:
     name: Build the integration test image

collector/lib/Channel.h

@@ -0,0 +1,123 @@
+#ifndef COLLECTOR_CHANNEL_H
+#define COLLECTOR_CHANNEL_H
+
+#include <atomic>
+#include <condition_variable>
+#include <cstddef>
+#include <iterator>
+#include <mutex>
+#include <queue>
+
+namespace collector {
+template <typename T>
+class Channel {
+ public:
+  using value_type = T;
+
+  Channel(std::size_t capacity = 0)
+      : capacity_(capacity) {
+  }
+
+  bool IsClosed() {
+    return closed_.load();
+  }
+
+  void Close() {
+    closed_.store(true);
+    cv_.notify_all();
+  }
+
+  friend Channel<T>& operator<<(Channel<T>& ch, const T& data) {
+    if (ch.IsClosed()) {
+      // If the channel is closed we simply drop messages
+      return ch;
+    }
+
+    std::unique_lock<std::mutex> lock{ch.mutex_};
+    if (ch.capacity_ > 0 && ch.queue_.size() >= ch.capacity_) {
+      ch.cv_.wait(lock, [&ch] { return ch.queue_.size() < ch.capacity_; });
+    }
+
+    ch.queue_.push(data);
+    ch.cv_.notify_one();
+
+    return ch;
+  }
+
+  friend Channel<T>& operator<<(Channel<T>& ch, T&& data) {
+    if (ch.IsClosed()) {
+      // If the channel is closed we simply drop messages
+      return ch;
+    }
+
+    std::unique_lock<std::mutex> lock{ch.mutex_};
+    if (ch.capacity_ > 0 && ch.queue_.size() >= ch.capacity_) {
+      ch.cv_.wait(lock, [&ch] { return ch.queue_.size() < ch.capacity_; });
+    }
+
+    ch.queue_.push(std::move(data));
+    ch.cv_.notify_one();
+
+    return ch;
+  }
+
+  friend Channel<T>& operator>>(Channel<T>& ch, T& out) {
+    std::unique_lock<std::mutex> lock{ch.mutex_};
+    if (ch.IsClosed() && ch.queue_.empty()) {
+      return ch;
+    }
+
+    ch.cv_.wait(lock, [&ch] { return !ch.queue_.empty() || ch.IsClosed(); });
+    if (!ch.queue_.empty()) {
+      out = std::move(ch.queue_.front());
+      ch.queue_.pop();
+    }
+
+    ch.cv_.notify_one();
+    return ch;
+  }
+
+  bool Empty() {
+    std::unique_lock<std::mutex> lock{mutex_};
+    return queue_.empty();
+  }
+
+  struct Iterator {
+    Iterator(Channel<T>& ch) : ch_(ch) {}
+
+    using iterator_category = std::input_iterator_tag;
+    using value_type = T;
+    using reference = T&;
+    using pointer = T*;
+
+    Iterator operator++() { return *this; }
+    reference operator*() {
+      ch_ >> value_;
+      return value_;
+    }
+
+    bool operator!=(Iterator& /*unused*/) const {
+      std::unique_lock<std::mutex> lock{ch_.mutex_};
+      ch_.cv_.wait(lock, [this] { return !ch_.queue_.empty() || ch_.IsClosed(); });
+
+      return !(ch_.IsClosed() && ch_.queue_.empty());
+    }
+
+   private:
+    Channel<T>& ch_;
+    value_type value_;
+  };
+
+  Iterator begin() { return Iterator{*this}; }
+  Iterator end() { return Iterator{*this}; }
+
+ private:
+  std::size_t capacity_;
+  std::queue<T> queue_;
+  std::mutex mutex_;
+  std::condition_variable cv_;
+  std::atomic<bool> closed_{false};
+};
+}  // namespace collector
+
+#endif

collector/lib/CollectorService.cpp

@@ -40,8 +40,7 @@ CollectorService::CollectorService(CollectorConfig& config, std::atomic<ControlV
   // Network tracking
   if (!config_.grpc_channel || !config_.DisableNetworkFlows()) {
     // In case if no GRPC is used, continue to setup networking infrasturcture
-    // with empty grpc_channel. NetworkConnectionInfoServiceComm will pick it
-    // up and use stdout instead.
+    // with empty grpc_channel. output_ will pick it up and use stdout instead.
     conn_tracker_ = std::make_shared<ConnectionTracker>();
     UnorderedSet<L4ProtoPortPair> ignored_l4proto_port_pairs(config_.IgnoredL4ProtoPortPairs());
     conn_tracker_->UpdateIgnoredL4ProtoPortPairs(std::move(ignored_l4proto_port_pairs));
@@ -52,6 +51,7 @@ CollectorService::CollectorService(CollectorConfig& config, std::atomic<ControlV
         conn_tracker_,
         config_,
         &system_inspector_,
+        &output_,
         exporter_.GetRegistry().get());
 
     auto network_signal_handler = std::make_unique<NetworkSignalHandler>(system_inspector_.GetInspector(), conn_tracker_, system_inspector_.GetUserspaceStats());
@@ -98,6 +98,12 @@ void CollectorService::RunForever() {
 
   CLOG(INFO) << "Network scrape interval set to " << config_.ScrapeInterval() << " seconds";
 
+  auto should_stop = [this] {
+    return control_->load(std::memory_order_relaxed) == STOP_COLLECTOR;
+  };
+
+  output_.WaitReady(should_stop);
+
   if (net_status_notifier_) {
     net_status_notifier_->Start();
   }
@@ -108,8 +114,7 @@ void CollectorService::RunForever() {
 
   system_inspector_.Start();
 
-  ControlValue cv;
-  while ((cv = control_->load(std::memory_order_relaxed)) != STOP_COLLECTOR) {
+  while (!should_stop()) {
     system_inspector_.Run(*control_);
     CLOG(DEBUG) << "Interrupted collector!";
   }
@@ -123,12 +128,6 @@ void CollectorService::RunForever() {
   CLOG(INFO) << "Shutting down collector.";
 }
 
-bool CollectorService::WaitForGRPCServer() {
-  std::string error_str;
-  auto interrupt = [this] { return control_->load(std::memory_order_relaxed) == STOP_COLLECTOR; };
-  return WaitForChannelReady(config_.grpc_channel, interrupt);
-}
-
 bool CollectorService::InitKernel() {
   auto& startup_diagnostics = StartupDiagnostics::GetInstance();
   std::string cm_name(CollectionMethodName(config_.GetCollectionMethod()));

collector/lib/CollectorService.h

@@ -30,8 +30,6 @@ class CollectorService {
   bool InitKernel();
 
  private:
-  bool WaitForGRPCServer();
-
   CollectorConfig& config_;
   output::Output output_;
   system_inspector::Service system_inspector_;
@@ -53,7 +51,6 @@ class CollectorService {
   std::shared_ptr<ConnectionTracker> conn_tracker_;
   std::unique_ptr<NetworkStatusNotifier> net_status_notifier_;
   std::shared_ptr<ProcessStore> process_store_;
-  std::shared_ptr<NetworkConnectionInfoServiceComm> network_connection_info_service_comm_;
 };
 
 }  // namespace collector