Cherry-pick #20146 to 7.x: [Elastic Agent] Add basic protocol to control Elastic Agent.

NOTICE.txt

@@ -16011,6 +16011,43 @@ Contents of probable licence file $GOMODCACHE/google.golang.org/grpc@v1.29.1/LIC
    limitations under the License.
 
 
+--------------------------------------------------------------------------------
+Dependency : google.golang.org/protobuf
+Version: v1.23.0
+Licence type (autodetected): BSD-3-Clause
+--------------------------------------------------------------------------------
+
+Contents of probable licence file $GOMODCACHE/google.golang.org/protobuf@v1.23.0/LICENSE:
+
+Copyright (c) 2018 The Go Authors. All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+   * Redistributions of source code must retain the above copyright
+notice, this list of conditions and the following disclaimer.
+   * Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the following disclaimer
+in the documentation and/or other materials provided with the
+distribution.
+   * Neither the name of Google Inc. nor the names of its
+contributors may be used to endorse or promote products derived from
+this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+
 --------------------------------------------------------------------------------
 Dependency : gopkg.in/inf.v0
 Version: v0.9.1
@@ -38509,43 +38546,6 @@ Contents of probable licence file $GOMODCACHE/google.golang.org/appengine@v1.6.5
    limitations under the License.
 
 
---------------------------------------------------------------------------------
-Dependency : google.golang.org/protobuf
-Version: v1.23.0
-Licence type (autodetected): BSD-3-Clause
---------------------------------------------------------------------------------
-
-Contents of probable licence file $GOMODCACHE/google.golang.org/protobuf@v1.23.0/LICENSE:
-
-Copyright (c) 2018 The Go Authors. All rights reserved.
-
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are
-met:
-
-   * Redistributions of source code must retain the above copyright
-notice, this list of conditions and the following disclaimer.
-   * Redistributions in binary form must reproduce the above
-copyright notice, this list of conditions and the following disclaimer
-in the documentation and/or other materials provided with the
-distribution.
-   * Neither the name of Google Inc. nor the names of its
-contributors may be used to endorse or promote products derived from
-this software without specific prior written permission.
-
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
-SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
-LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
-OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-
-
 --------------------------------------------------------------------------------
 Dependency : gopkg.in/airbrake/gobrake.v2
 Version: v2.0.9

go.mod

@@ -170,6 +170,7 @@ require (
 	google.golang.org/api v0.15.0
 	google.golang.org/genproto v0.0.0-20191230161307-f3c370f40bfb
 	google.golang.org/grpc v1.29.1
+	google.golang.org/protobuf v1.23.0
 	gopkg.in/inf.v0 v0.9.1
 	gopkg.in/jcmturner/gokrb5.v7 v7.5.0
 	gopkg.in/mgo.v2 v2.0.0-20160818020120-3f83fa500528

x-pack/elastic-agent/control.proto

@@ -0,0 +1,119 @@
+// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+// or more contributor license agreements. Licensed under the Elastic License;
+// you may not use this file except in compliance with the Elastic License.
+
+syntax = "proto3";
+
+package proto;
+
+option cc_enable_arenas = true;
+option go_package = "pkg/agent/control/proto;proto";
+
+// Status codes for the current state.
+enum Status {
+  STARTING = 0;
+  CONFIGURING = 1;
+  HEALTHY = 2;
+  DEGRADED = 3;
+  FAILED = 4;
+  STOPPING = 5;
+  UPGRADING = 6;
+  ROLLBACK = 7;
+}
+
+// Action status codes for restart and upgrade response.
+enum ActionStatus {
+  // Action was successful.
+  SUCCESS = 0;
+  // Action failed.
+  FAILURE = 1;
+}
+
+// Empty message.
+message Empty {
+}
+
+// Version response message.
+message VersionResponse {
+  // Current running version.
+  string version = 1;
+  // Current running commit.
+  string commit = 2;
+  // Current running build time.
+  string buildTime = 3;
+  // Current running version is a snapshot.
+  bool snapshot = 4;
+}
+
+message RestartResponse {
+  // Response status.
+  ActionStatus status = 1;
+  // Error message when it fails to trigger restart.
+  string error = 2;
+}
+
+// Upgrade request message.
+message UpgradeRequest {
+  // (Optional) Version to upgrade to.
+  //
+  // If not provided Elastic Agent will auto discover the latest version in the same major
+  // to upgrade to. If wanting to upgrade to a new major that major must be present in the
+  // this version field.
+  string version = 1;
+
+  // (Optional) Use a different source URI then configured.
+  //
+  // If provided the upgrade process will use the provided sourceURI instead of the configured
+  // sourceURI in the configuration.
+  string sourceURI = 2;
+}
+
+// A upgrade response message.
+message UpgradeResponse {
+  // Response status.
+  ActionStatus status = 1;
+
+  // Version that is being upgraded to.
+  string version = 2;
+
+  // Error message when it fails to trigger upgrade.
+  string error = 3;
+}
+
+// Current status of the application in Elastic Agent.
+message ApplicationStatus {
+  // Unique application ID.
+  string id = 1;
+  // Application name.
+  string name = 2;
+  // Current status.
+  Status status = 3;
+  // Current status message.
+  string message = 4;
+  // Current status payload.
+  string payload = 5;
+}
+
+// Status is the current status of Elastic Agent.
+message StatusResponse {
+  // Overall status of Elastic Agent.
+  Status status = 1;
+  // Overall status message of Elastic Agent.
+  string message = 2;
+  // Status of each application in Elastic Agent.
+  repeated ApplicationStatus applications = 3;
+}
+
+service ElasticAgent {
+  // Fetches the currently running version of the Elastic Agent.
+  rpc Version(Empty) returns (VersionResponse);
+
+  // Fetches the currently status of the Elastic Agent.
+  rpc Status(Empty) returns (StatusResponse);
+
+  // Restart restarts the current running Elastic Agent.
+  rpc Restart(Empty) returns (RestartResponse);
+
+  // Upgrade starts the upgrade process of Elastic Agent.
+  rpc Upgrade(UpgradeRequest) returns (UpgradeResponse);
+}

x-pack/elastic-agent/magefile.go

@@ -321,7 +321,7 @@ func commitID() string {
 	return commitID
 }
 
-// Update is an alias for executing fields, dashboards, config, includes.
+// Update is an alias for executing control protocol, configs, and specs.
 func Update() {
 	mg.SerialDeps(Config, BuildSpec, BuildFleetCfg)
 }
@@ -341,6 +341,11 @@ func Config() {
 	mg.Deps(configYML)
 }
 
+// ControlProto generates pkg/agent/control/proto module.
+func ControlProto() error {
+	return sh.RunV("protoc", "--go_out=plugins=grpc:.", "control.proto")
+}
+
 // BuildSpec make sure that all the suppported program spec are built into the binary.
 func BuildSpec() error {
 	// go run x-pack/agent/dev-tools/cmd/buildspec/buildspec.go --in x-pack/agent/spec/*.yml --out x-pack/agent/pkg/agent/program/supported.go