main.go

// Copyright 2020 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

package main

import (
	"context"
	"flag"
	"log"
	"os"

	_ "github.com/GoogleCloudPlatform/ops-agent/apps"
	"github.com/GoogleCloudPlatform/ops-agent/confgenerator"
	"github.com/GoogleCloudPlatform/ops-agent/internal/healthchecks"
	"github.com/GoogleCloudPlatform/ops-agent/internal/logs"
	"github.com/GoogleCloudPlatform/ops-agent/internal/self_metrics"
)

var (
	service      = flag.String("service", "", "service to generate config for")
	outDir       = flag.String("out", os.Getenv("RUNTIME_DIRECTORY"), "directory to write configuration files to")
	input        = flag.String("in", "/etc/google-cloud-ops-agent/config.yaml", "path to the user specified agent config")
	logsDir      = flag.String("logs", "/var/log/google-cloud-ops-agent", "path to store agent logs")
	stateDir     = flag.String("state", "/var/lib/google-cloud-ops-agent", "path to store agent state like buffers")
	healthChecks = flag.Bool("healthchecks", false, "run health checks and exit")
)

func runHealthChecks(otlpExporterEnabled bool) {
	logger := healthchecks.CreateHealthChecksLogger(*logsDir)

	defaultLogger := logs.NewSimpleLogger()

	healthCheckResults := healthchecks.HealthCheckRegistryFactory(otlpExporterEnabled).RunAllHealthChecks(logger)
	healthchecks.LogHealthCheckResults(healthCheckResults, defaultLogger)
}

func main() {
	flag.Parse()
	if err := run(); err != nil {
		log.Fatalf("The agent config file is not valid. Detailed error: %s", err)
	}
}

func run() error {
	ctx := context.Background()
	// TODO(lingshi) Move this to a shared place across Linux and Windows.
	uc, err := confgenerator.MergeConfFiles(ctx, *input)
	if err != nil {
		return err
	}
	// Log the built-in and merged config files to STDOUT. These are then written
	// by journald to var/log/syslog and so to Cloud Logging once the ops-agent is
	// running.
	log.Printf("Built-in config:\n%s", confgenerator.BuiltInConfStructs["linux"])
	log.Printf("Merged config:\n%s", uc)

	switch *service {
	case "":
		runHealthChecks(uc.Global.GetOtlpExporter())
		log.Println("Startup checks finished")
		if *healthChecks {
			// If healthchecks is set, stop here
			return nil
		}
	case "otel":
		// The generated otlp metric json files are used only by the otel service.
		err = self_metrics.GenerateOpsAgentSelfMetricsOTLPJSON(ctx, *input, *outDir)
		if err != nil {
			return err
		}
	}
	return uc.GenerateFilesFromConfig(ctx, *service, *logsDir, *stateDir, *outDir)
}