admin/xDS: prepare for full /config_dump and version support (#3199)

This change does several things:
1) Clarifies how we handle xDS version_info in responses and sets us up
   for both top-level/transactional versions as well as per-resource
   versions in the future.
2) Moves the config_dump admin endpoint to the v2alpha namespace so that
   we can iterate on it in the future.
3) Fills out the config dump proto for the remaining resource types.
   These are not implemented but are here to force a discussion about
   how we want to handle versions moving forward.
4) Fixes RDS static config dump to actually work and add better tests.
5) Wire up version for the RDS config dump on a per-resource basis.

Once we agree on the general version semantics I will be following up
with dump capability of the remaining resource types.

Part of envoyproxy/envoy#2421
Part of envoyproxy/envoy#2172
Fixes envoyproxy/envoy#3141

Signed-off-by: Matt Klein <mklein@lyft.com>

Mirrored from https://github.com/envoyproxy/envoy @ ada758739907628b50079b9adfccf5481ec9fc5f

envoy/admin/v2/BUILD → envoy/admin/v2alpha/BUILD

@@ -7,6 +7,9 @@ api_proto_library(
     srcs = ["config_dump.proto"],
     visibility = ["//visibility:public"],
     deps = [
+        "//envoy/api/v2:cds",
+        "//envoy/api/v2:lds",
         "//envoy/api/v2:rds",
+        "//envoy/config/bootstrap/v2:bootstrap",
     ],
 )

envoy/admin/v2alpha/config_dump.proto

@@ -0,0 +1,131 @@
+syntax = "proto3";
+
+package envoy.admin.v2alpha;
+
+import "envoy/api/v2/cds.proto";
+import "envoy/api/v2/lds.proto";
+import "envoy/api/v2/rds.proto";
+import "envoy/config/bootstrap/v2/bootstrap.proto";
+
+import "google/protobuf/any.proto";
+
+import "gogoproto/gogo.proto";
+
+// [#protodoc-title: ConfigDump]
+
+// The /config_dump admin endpoint uses this wrapper message to maintain and serve arbitrary
+// configuration information from any component in Envoy.
+// TODO(jsedgwick) In the future, we may want to formalize this further with an RPC for config_dump,
+// and perhaps even with an RPC per config type. That strategy across all endpoints will allow for
+// more flexibility w.r.t. protocol, serialization, parameters, etc.
+message ConfigDump {
+  // This map is serialized and dumped in its entirety at the /config_dump endpoint.
+  //
+  // Keys should be a short descriptor of the config object they map to. For example, Envoy's HTTP
+  // routing subsystem might use "routes" as the key for its config, for which it uses the message
+  // RouteConfigDump as defined below. In the future, the key will also be used to filter the output
+  // of the /config_dump endpoint.
+  map<string, google.protobuf.Any> configs = 1 [(gogoproto.nullable) = false];
+}
+
+// This message describes the bootstrap configuration that Envoy was started with. This includes
+// any CLI overrides that were merged. Bootstrap configuration information can be used to recreate
+// the static portions of an Envoy configuration by reusing the output as the bootstrap
+// configuration for another Envoy.
+message BootstrapConfigDump {
+  envoy.config.bootstrap.v2.Bootstrap bootstrap = 1 [(gogoproto.nullable) = false];
+}
+
+// Envoy's listener manager fills this message with all currently known listeners. Listener
+// configuration information can be used to recreate an Envoy configuration by populating all
+// listeners as static listeners or by returning them in a LDS response.
+message ListenersConfigDump {
+  // This is the *version_info* in the last processed LDS discovery response. If there
+  // are only static bootstrap listeners, this field will be "".
+  string version_info = 1;
+
+  // Describes a dynamically loaded cluster via the LDS API.
+  message DynamicListener {
+    // This is the per-resource version information. This version is currently taken from the
+    // *version_info* field at the time that the listener was loaded. In the future, discrete
+    // per-listener versions may be supported by the API.
+    string version_info = 1;
+
+    // The listener config.
+    envoy.api.v2.Listener listener = 2;
+  }
+
+  // The statically loaded listener configs.
+  repeated envoy.api.v2.Listener static_listeners = 2 [(gogoproto.nullable) = false];
+
+  // The dynamically loaded active listeners. These are listeners that are available to service
+  // data plane traffic.
+  repeated DynamicListener dynamic_active_listeners = 3 [(gogoproto.nullable) = false];
+
+  // The dynamically loaded warming listeners. These are listeners that are currently undergoing
+  // warming in preparation to service data plane traffic. Note that if attempting to recreate an
+  // Envoy configuration from a configuration dump, the warming listeners should generally be
+  // discarded.
+  repeated DynamicListener dynamic_warming_listeners = 4 [(gogoproto.nullable) = false];
+
+  // The dynamically loaded draining listeners. These are listeners that are currently undergoing
+  // draining in preparation to stop servicing data plane traffic. Note that if attempting to
+  // recreate an Envoy configuration from a configuration dump, the draining listeners should
+  // generally be discarded.
+  repeated DynamicListener dynamic_draining_listeners = 5 [(gogoproto.nullable) = false];
+}
+
+// Envoy's cluster manager fills this message with all currently known clusters. Cluster
+// configuration information can be used to recreate an Envoy configuration by populating all
+// clusters as static clusters or by returning them in a CDS response.
+message ClustersConfigDump {
+  // This is the *version_info* in the last processed CDS discovery response. If there
+  // are only static bootstrap clusters, this field will be "".
+  string version_info = 1;
+
+  // Describes a dynamically loaded cluster via the CDS API.
+  message DynamicCluster {
+    // This is the per-resource version information. This version is currently taken from the
+    // *version_info* field at the time that the cluster was loaded. In the future, discrete
+    // per-cluster versions may be supported by the API.
+    string version_info = 1;
+
+    // The cluster config.
+    envoy.api.v2.Cluster cluster = 2;
+  }
+
+  // The statically loaded cluster configs.
+  repeated envoy.api.v2.Cluster static_clusters = 2 [(gogoproto.nullable) = false];
+
+  // The dynamically loaded active clusters. These are clusters that are available to service
+  // data plane traffic.
+  repeated DynamicCluster dynamic_active_clusters = 3 [(gogoproto.nullable) = false];
+
+  // The dynamically loaded warming clusters. These are clusters that are currently undergoing
+  // warming in preparation to service data plane traffic. Note that if attempting to recreate an
+  // Envoy configuration from a configuration dump, the warming clusters should generally be
+  // discarded.
+  repeated DynamicCluster dynamic_warming_clusters = 4 [(gogoproto.nullable) = false];
+}
+
+// Envoy's RDS implementation fills this message with all currently loaded routes, as described by
+// their RouteConfiguration objects. Static routes configured in the bootstrap configuration are
+// separated from those configured dynamically via RDS. Route configuration information can be used
+// to recreate an Envoy configuration by populating all routes as static routes or by returning them
+// in RDS responses.
+message RoutesConfigDump {
+  message DynamicRouteConfig {
+    // This is the per-resource version information. This version is currently taken from the
+    // *version_info* field at the time that the route configuration was loaded.
+    string version_info = 1;
+
+    // The route config.
+    envoy.api.v2.RouteConfiguration route_config = 2;
+  }
+
+  // The statically loaded route configs.
+  repeated envoy.api.v2.RouteConfiguration static_route_configs = 2 [(gogoproto.nullable) = false];
+
+  // The dynamically loaded route configs.
+  repeated DynamicRouteConfig dynamic_route_configs = 3 [(gogoproto.nullable) = false];
+}

envoy/config/bootstrap/v2/BUILD

@@ -5,6 +5,7 @@ licenses(["notice"])  # Apache 2
 api_proto_library(
     name = "bootstrap",
     srcs = ["bootstrap.proto"],
+    visibility = ["//visibility:public"],
     deps = [
         "//envoy/api/v2:cds",
         "//envoy/api/v2:lds",