kiali.go

// Kiali
//
// # Kiali Project, The Console for Istio Service Mesh
//
// NOTE! The Kiali API is not for public use and is not supported for any use outside of the Kiali UI itself.
// The API can and will change from version to version with no guarantee of backwards compatibility.
//
// To generate this API document:
// ```
//
//	> alias swagger='docker run --rm -it  --user $(id -u):$(id -g) -e GOCACHE=/tmp -e GOPATH=$(go env GOPATH):/go -v $HOME:$HOME -w $(pwd) quay.io/goswagger/swagger'
//	> swagger generate spec -o ./swagger.json
//	> swagger generate markdown --quiet --spec ./swagger.json --output ./kiali_internal_api.md
//
// ```
//
//	Schemes: http, https
//	BasePath: /api
//	Version: _
//
//	Consumes:
//	- application/json
//
//	Produces:
//	- application/json
//
// swagger:meta
package main

import (
	"context"
	"flag"
	"os"
	"os/signal"
	"strings"
	"syscall"

	_ "go.uber.org/automaxprocs"

	"github.com/kiali/kiali/business"
	"github.com/kiali/kiali/config"
	"github.com/kiali/kiali/istio"
	"github.com/kiali/kiali/kubernetes"
	"github.com/kiali/kiali/kubernetes/cache"
	"github.com/kiali/kiali/log"
	"github.com/kiali/kiali/models"
	"github.com/kiali/kiali/prometheus"
	"github.com/kiali/kiali/prometheus/internalmetrics"
	"github.com/kiali/kiali/server"
	"github.com/kiali/kiali/tracing"
	"github.com/kiali/kiali/util"
)

// Identifies the build. These are set via ldflags during the build (see Makefile).
var (
	version    = "unknown"
	commitHash = "unknown"
	goVersion  = "unknown"
)

// Command line arguments
var (
	argConfigFile = flag.String("config", "", "Path to the YAML configuration file. If not specified, environment variables will be used for configuration.")
)

func init() {
	// log everything to stderr so that it can be easily gathered by logs, separate log files are problematic with containers
	_ = flag.Set("logtostderr", "true")
}

func main() {
	log.InitializeLogger()
	util.Clock = util.RealClock{}

	// process command line
	flag.Parse()
	validateFlags()

	// log startup information
	log.Infof("Kiali: Version: %v, Commit: %v, Go: %v", version, commitHash, goVersion)
	log.Debugf("Kiali: Command line: [%v]", strings.Join(os.Args, " "))

	// load config file if specified, otherwise, rely on environment variables to configure us
	if *argConfigFile != "" {
		c, err := config.LoadFromFile(*argConfigFile)
		if err != nil {
			log.Fatal(err)
		}
		config.Set(c)
	} else {
		log.Infof("No configuration file specified. Will rely on environment for configuration.")
		config.Set(config.NewConfig())
	}

	updateConfigWithIstioInfo()

	cfg := config.Get()
	log.Tracef("Kiali Configuration:\n%s", cfg)

	if err := config.Validate(*cfg); err != nil {
		log.Fatal(err)
	}

	// prepare our internal metrics so Prometheus can scrape them
	internalmetrics.RegisterInternalMetrics()

	// Create the business package dependencies.
	clientFactory, err := kubernetes.GetClientFactory()
	if err != nil {
		log.Fatalf("Failed to create client factory. Err: %s", err)
	}

	log.Info("Initializing Kiali Cache")
	cache, err := cache.NewKialiCache(clientFactory, *cfg)
	if err != nil {
		log.Fatalf("Error initializing Kiali Cache. Details: %s", err)
	}
	defer cache.Stop()

	cache.SetBuildInfo(models.BuildInfo{
		CommitHash:       commitHash,
		ContainerVersion: determineContainerVersion(version),
		GoVersion:        goVersion,
		Version:          version,
	})

	discovery := istio.NewDiscovery(clientFactory.GetSAClients(), cache, cfg)
	cpm := business.NewControlPlaneMonitor(cache, clientFactory, *cfg, discovery)

	// This context is used for polling and for creating some high level clients like tracing.
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	if cfg.ExternalServices.Istio.IstioAPIEnabled {
		cpm.PollIstiodForProxyStatus(ctx)
	}

	// Create shared prometheus client shared by all prometheus requests in the business layer.
	prom, err := prometheus.NewClient()
	if err != nil {
		log.Fatalf("Error creating Prometheus client: %s", err)
	}

	// Create shared tracing client shared by all tracing requests in the business layer.
	// Because tracing is not an essential component, we don't want to block startup
	// of the server if the tracing client fails to initialize. tracing.NewClient will
	// continue to retry until the client is initialized or the context is cancelled.
	// Passing in a loader function allows the tracing client to be used once it is
	// finally initialized.
	var tracingClient tracing.ClientInterface
	tracingLoader := func() tracing.ClientInterface {
		return tracingClient
	}
	if cfg.ExternalServices.Tracing.Enabled {
		go func() {
			client, err := tracing.NewClient(ctx, cfg, clientFactory.GetSAHomeClusterClient().GetToken())
			if err != nil {
				log.Fatalf("Error creating tracing client: %s", err)
				return
			}
			tracingClient = client
		}()
	} else {
		log.Debug("Tracing is disabled")
	}

	// Start listening to requests
	server, err := server.NewServer(cpm, clientFactory, cache, cfg, prom, tracingLoader, discovery)
	if err != nil {
		log.Fatal(err)
	}
	server.Start()

	// wait forever, or at least until we are told to exit
	waitForTermination()

	// Shutdown internal components
	log.Info("Shutting down internal components")
	server.Stop()
}

func waitForTermination() {
	// Channel that is notified when we are done and should exit
	// TODO: may want to make this a package variable - other things might want to tell us to exit
	doneChan := make(chan bool)

	signalChan := make(chan os.Signal, 1)
	signal.Notify(signalChan, syscall.SIGINT, syscall.SIGTERM)
	go func() {
		for range signalChan {
			log.Info("Termination Signal Received")
			doneChan <- true
		}
	}()

	<-doneChan
}

func validateFlags() {
	if *argConfigFile != "" {
		if _, err := os.Stat(*argConfigFile); err != nil {
			if os.IsNotExist(err) {
				log.Debugf("Configuration file [%v] does not exist.", *argConfigFile)
			}
		}
	}
}

// determineContainerVersion will return the version of the image container.
// It does this by looking at an ENV defined in the Dockerfile when the image is built.
// If the ENV is not defined, the version is assumed the same as the given default value.
func determineContainerVersion(defaultVersion string) string {
	v := os.Getenv("KIALI_CONTAINER_VERSION")
	if v == "" {
		return defaultVersion
	}
	return v
}

// This is used to update the config with information about istio that
// comes from the environment such as the cluster name.
func updateConfigWithIstioInfo() {
	conf := *config.Get()

	homeCluster := conf.KubernetesConfig.ClusterName
	if homeCluster != "" {
		// If the cluster name is already set, we don't need to do anything
		return
	}

	err := func() error {
		log.Debug("Cluster name is not set. Attempting to auto-detect the cluster name from the home cluster environment.")
		ctx, cancel := context.WithCancel(context.Background())
		defer cancel()

		// Need to create a temporary client factory here so that we can create a client
		// to auto-detect the istio cluster name from the environment. There's a bit of a
		// chicken and egg problem with the client factory because the client factory
		// uses the cluster id to keep track of all the clients. But in order to create
		// a client to get the cluster id from the environment, you need to create a client factory.
		// To get around that we create a temporary client factory here and then set the kiali
		// config cluster name. We then create the global client factory later in the business
		// package and that global client factory has the cluster id set properly.
		cf, err := kubernetes.NewClientFactory(ctx, conf)
		if err != nil {
			return err
		}

		// Try to auto-detect the cluster name
		homeCluster, err = kubernetes.ClusterNameFromIstiod(conf, cf.GetSAHomeClusterClient())
		if err != nil {
			return err
		}

		return nil
	}()
	if err != nil {
		log.Warningf("Cannot resolve local cluster name. Err: %s. Falling back to [%s]", err, config.DefaultClusterID)
		homeCluster = config.DefaultClusterID
	}

	log.Debugf("Auto-detected the istio cluster name to be [%s]. Updating the kiali config", homeCluster)
	conf.KubernetesConfig.ClusterName = homeCluster
	config.Set(&conf)
}