listener manager: implement dynamic add/remove

docs/configuration/listeners/listeners.rst

@@ -9,6 +9,7 @@ Each individual listener configuration has the following format:
 .. code-block:: json
 
   {
+    "name": "...",
     "address": "...",
     "filters": [],
     "ssl_context": "{...}",
@@ -18,6 +19,11 @@ Each individual listener configuration has the following format:
     "per_connection_buffer_limit_bytes": "..."
   }
 
+name
+  *(optional, string)* The unique name by which this listener is known. If no name is provided,
+  Envoy will allocate an internal UUID for the listener. If the listener is to be dynamically
+  updated or removed via LDS a unique name must be provided.
+
 address
   *(required, string)* The address that the listener should listen on. Currently only TCP
   listeners are supported, e.g., "tcp://127.0.0.1:80". Note, "tcp://0.0.0.0:80" is the wild card

include/envoy/network/address.h

@@ -92,6 +92,7 @@ class Instance {
   virtual ~Instance() {}
 
   virtual bool operator==(const Instance& rhs) const PURE;
+  bool operator!=(const Instance& rhs) const { return !operator==(rhs); }
 
   /**
    * @return a human readable string for the address.

include/envoy/network/listen_socket.h

@@ -32,6 +32,7 @@ class ListenSocket {
 };
 
 typedef std::unique_ptr<ListenSocket> ListenSocketPtr;
+typedef std::shared_ptr<ListenSocket> ListenSocketSharedPtr;
 
 } // namespace Network
 } // namespace Envoy

include/envoy/server/listener_manager.h

@@ -21,9 +21,9 @@ class ListenerComponentFactory {
    * Creates a socket.
    * @param address supplies the socket's address.
    * @param bind_to_port supplies whether to actually bind the socket.
-   * @return Network::ListenSocketPtr an initialized and potentially bound socket.
+   * @return Network::ListenSocketSharedPtr an initialized and potentially bound socket.
    */
-  virtual Network::ListenSocketPtr
+  virtual Network::ListenSocketSharedPtr
   createListenSocket(Network::Address::InstanceConstSharedPtr address, bool bind_to_port) PURE;
 
   /**
@@ -55,15 +55,9 @@ class Listener {
    */
   virtual Network::FilterChainFactory& filterChainFactory() PURE;
 
-  /**
-   * @return Network::Address::InstanceConstSharedPtr the configured address for the listener. This
-   *         may be distinct to the bound address, e.g. if the port is zero.
-   */
-  virtual Network::Address::InstanceConstSharedPtr address() PURE;
-
   /**
    * @return Network::ListenSocket& the actual listen socket. The address of this socket may be
-   *         different from address() if for example the configured address binds to port zero.
+   *         different from configured if for example the configured address binds to port zero.
    */
   virtual Network::ListenSocket& socket() PURE;
 
@@ -108,8 +102,6 @@ class Listener {
   virtual uint64_t listenerTag() PURE;
 };
 
-typedef std::unique_ptr<Listener> ListenerPtr;
-
 /**
  * A manager for all listeners and all threaded connection handling workers.
  */
@@ -118,22 +110,40 @@ class ListenerManager {
   virtual ~ListenerManager() {}
 
   /**
-   * Add a listener to the manager.
-   * @param json supplies the configuration JSON. Will throw an EnvoyException if the listener can
-   *        not be added.
+   * Add or update a listener. Listeners are referenced by a unique name. If no name is provided,
+   * the manager will allocate a UUID. Listeners that expect to be dynamically updated should
+   * provide a unique name. The manager will search by name to find the existing listener that
+   * should be updated. The new listener must have the same configured address. The old listener
+   * will be gracefully drained once the new listener is ready to take traffic (e.g. when RDS has
+   * been initialized).
+   * @param json supplies the configuration JSON.
+   * @return TRUE if a listener was added or FALSE if the listener was not updated because it is
+   *         a duplicate of the existing listener. This routine will throw an EnvoyException if
+   *         there is a fundamental error preventing the listener from being added or updated.
    */
-  virtual void addListener(const Json::Object& json) PURE;
+  virtual bool addOrUpdateListener(const Json::Object& json) PURE;
 
   /**
-   * @return std::list<std::reference_wrapper<Listener>> a list of the currently loaded listeners.
+   * @return std::vector<std::reference_wrapper<Listener>> a list of the currently loaded listeners.
+   * Note that this routine returns references to the existing listeners. The references are only
+   * valid in the context of the current call stack and should not be stored.
    */
-  virtual std::list<std::reference_wrapper<Listener>> listeners() PURE;
+  virtual std::vector<std::reference_wrapper<Listener>> listeners() PURE;
 
   /**
    * @return uint64_t the total number of connections owned by all listeners across all workers.
    */
   virtual uint64_t numConnections() PURE;
 
+  /**
+   * Remove a listener by name.
+   * @param name supplies the listener name to remove.
+   * @return TRUE if the listener was found and removed. Note that when this routine returns TRUE,
+   * the listener has not necessarily been actually deleted right away. The listener will be
+   * drained and fully removed at some later time.
+   */
+  virtual bool removeListener(const std::string& name) PURE;
+
   /**
    * Start all workers accepting new connections on all added listeners.
    * @param guard_dog supplies the guard dog to use for thread watching.

source/common/json/config_schemas.cc

@@ -43,6 +43,7 @@ const std::string Json::Schema::LISTENER_SCHEMA(R"EOF(
     },
     "type" : "object",
     "properties": {
+       "name": {"type": "string"},
        "address": {"type": "string"},
        "filters" : {
          "type" : "array",

source/exe/hot_restart.cc

@@ -176,7 +176,7 @@ void HotRestartImpl::drainParentListeners() {
 }
 
 int HotRestartImpl::duplicateParentListenSocket(const std::string& address) {
-  if (options_.restartEpoch() == 0) {
+  if (options_.restartEpoch() == 0 || parent_terminated_) {
     return -1;
   }
 

source/server/BUILD

@@ -34,12 +34,9 @@ envoy_cc_library(
         "//source/common/common:logger_lib",
         "//source/common/common:utility_lib",
         "//source/common/json:config_schemas_lib",
-        "//source/common/json:json_loader_lib",
         "//source/common/network:utility_lib",
         "//source/common/ratelimit:ratelimit_lib",
         "//source/common/tracing:http_tracer_lib",
-        "//source/common/tracing/zipkin:zipkin_lib",
-        "//source/common/upstream:cluster_manager_lib",
     ],
 )
 
@@ -125,6 +122,7 @@ envoy_cc_library(
     hdrs = ["listener_manager_impl.h"],
     deps = [
         ":configuration_lib",
+        ":init_manager_lib",
         "//include/envoy/registry",
         "//include/envoy/server:filter_config_interface",
         "//include/envoy/server:listener_manager_interface",
@@ -159,7 +157,6 @@ envoy_cc_library(
         "//include/envoy/server:instance_interface",
         "//include/envoy/server:listener_manager_interface",
         "//include/envoy/server:options_interface",
-        "//include/envoy/ssl:context_manager_interface",
         "//include/envoy/stats:stats_macros",
         "//include/envoy/tracing:http_tracer_interface",
         "//include/envoy/upstream:cluster_manager_interface",
@@ -171,6 +168,7 @@ envoy_cc_library(
         "//source/common/runtime:runtime_lib",
         "//source/common/stats:statsd_lib",
         "//source/common/thread_local:thread_local_lib",
+        "//source/common/upstream:cluster_manager_lib",
         "//source/server/http:admin_lib",
     ],
 )
@@ -198,6 +196,7 @@ envoy_cc_library(
     hdrs = ["worker_impl.h"],
     deps = [
         ":connection_handler_lib",
+        ":test_hooks_lib",
         "//include/envoy/api:api_interface",
         "//include/envoy/event:dispatcher_interface",
         "//include/envoy/event:timer_interface",

source/server/config_validation/server.h

@@ -92,8 +92,8 @@ class ValidationInstance : Logger::Loggable<Logger::Id::main>,
                           Configuration::FactoryContext& context) override {
     return ProdListenerComponentFactory::createFilterFactoryList_(filters, *this, context);
   }
-  Network::ListenSocketPtr createListenSocket(Network::Address::InstanceConstSharedPtr,
-                                              bool) override {
+  Network::ListenSocketSharedPtr createListenSocket(Network::Address::InstanceConstSharedPtr,
+                                                    bool) override {
     // Returned sockets are not currently used so we can return nothing here safely vs. a
     // validation mock.
     return nullptr;

source/server/configuration_impl.cc

@@ -16,7 +16,7 @@
 #include "common/common/utility.h"
 #include "common/json/config_schemas.h"
 #include "common/ratelimit/ratelimit_impl.h"
-#include "common/upstream/cluster_manager_impl.h"
+#include "common/tracing/http_tracer_impl.h"
 
 #include "spdlog/spdlog.h"
 
@@ -43,7 +43,7 @@ void MainImpl::initialize(const Json::Object& json, Instance& server,
   ENVOY_LOG(info, "loading {} listener(s)", listeners.size());
   for (size_t i = 0; i < listeners.size(); i++) {
     ENVOY_LOG(info, "listener #{}:", i);
-    server.listenerManager().addListener(*listeners[i]);
+    server.listenerManager().addOrUpdateListener(*listeners[i]);
   }
 
   if (json.hasObject("statsd_local_udp_port") && json.hasObject("statsd_udp_ip_address")) {