network enhanecment / refactor (#361)

* chore(network): improve connectivity check

* refactor(network): rewrite network and timesync component

* feat(display): show cloud connection status

* chore: change logging verbosity

* chore(websecure): update log message

* fix(ota): validate root certificate when downloading update

* feat(ui): add network settings tab

* fix(display): cloud connecting animation

* fix: golintci issues

* feat: add network settings tab

* feat(timesync): query servers in parallel

* refactor(network): move to internal/network package

* feat(timesync): add metrics

* refactor(log): move log to internal/logging package

* refactor(mdms): move mdns to internal/mdns package

* feat(developer): add pprof endpoint

* feat(logging): add a simple logging streaming endpoint

* fix(mdns): do not start mdns until network is up

* feat(network): allow users to update network settings from ui

* fix(network): handle errors when net.IPAddr is nil

* fix(mdns): scopedLogger SIGSEGV

* fix(dhcp): watch directory instead of file to catch fsnotify.Create event

* refactor(nbd): move platform-specific code to different files

* refactor(native): move platform-specific code to different files

* chore: fix linter issues

* chore(dev_deploy): allow to override PION_LOG_TRACE

internal/udhcpc/udhcpc.go

@@ -0,0 +1,191 @@
+package udhcpc
+
+import (
+	"errors"
+	"fmt"
+	"os"
+	"path/filepath"
+	"time"
+
+	"github.com/fsnotify/fsnotify"
+	"github.com/rs/zerolog"
+)
+
+const (
+	DHCPLeaseFile = "/run/udhcpc.%s.info"
+	DHCPPidFile   = "/run/udhcpc.%s.pid"
+)
+
+type DHCPClient struct {
+	InterfaceName string
+	leaseFile     string
+	pidFile       string
+	lease         *Lease
+	logger        *zerolog.Logger
+	process       *os.Process
+	onLeaseChange func(lease *Lease)
+}
+
+type DHCPClientOptions struct {
+	InterfaceName string
+	PidFile       string
+	Logger        *zerolog.Logger
+	OnLeaseChange func(lease *Lease)
+}
+
+var defaultLogger = zerolog.New(os.Stdout).Level(zerolog.InfoLevel)
+
+func NewDHCPClient(options *DHCPClientOptions) *DHCPClient {
+	if options.Logger == nil {
+		options.Logger = &defaultLogger
+	}
+
+	l := options.Logger.With().Str("interface", options.InterfaceName).Logger()
+	return &DHCPClient{
+		InterfaceName: options.InterfaceName,
+		logger:        &l,
+		leaseFile:     fmt.Sprintf(DHCPLeaseFile, options.InterfaceName),
+		pidFile:       options.PidFile,
+		onLeaseChange: options.OnLeaseChange,
+	}
+}
+
+func (c *DHCPClient) getWatchPaths() []string {
+	watchPaths := make(map[string]interface{})
+	watchPaths[filepath.Dir(c.leaseFile)] = nil
+
+	if c.pidFile != "" {
+		watchPaths[filepath.Dir(c.pidFile)] = nil
+	}
+
+	paths := make([]string, 0)
+	for path := range watchPaths {
+		paths = append(paths, path)
+	}
+	return paths
+}
+
+// Run starts the DHCP client and watches the lease file for changes.
+// this isn't a blocking call, and the lease file is reloaded when a change is detected.
+func (c *DHCPClient) Run() error {
+	err := c.loadLeaseFile()
+	if err != nil && !errors.Is(err, os.ErrNotExist) {
+		return err
+	}
+
+	watcher, err := fsnotify.NewWatcher()
+	if err != nil {
+		return err
+	}
+	defer watcher.Close()
+
+	go func() {
+		for {
+			select {
+			case event, ok := <-watcher.Events:
+				if !ok {
+					continue
+				}
+				if !event.Has(fsnotify.Write) && !event.Has(fsnotify.Create) {
+					continue
+				}
+
+				if event.Name == c.leaseFile {
+					c.logger.Debug().
+						Str("event", event.Op.String()).
+						Str("path", event.Name).
+						Msg("udhcpc lease file updated, reloading lease")
+					_ = c.loadLeaseFile()
+				}
+			case err, ok := <-watcher.Errors:
+				if !ok {
+					return
+				}
+				c.logger.Error().Err(err).Msg("error watching lease file")
+			}
+		}
+	}()
+
+	for _, path := range c.getWatchPaths() {
+		err = watcher.Add(path)
+		if err != nil {
+			c.logger.Error().
+				Err(err).
+				Str("path", path).
+				Msg("failed to watch directory")
+			return err
+		}
+	}
+
+	// TODO: update udhcpc pid file
+	// we'll comment this out for now because the pid might change
+	// process := c.GetProcess()
+	// if process == nil {
+	// 	c.logger.Error().Msg("udhcpc process not found")
+	// }
+
+	// block the goroutine until the lease file is updated
+	<-make(chan struct{})
+
+	return nil
+}
+
+func (c *DHCPClient) loadLeaseFile() error {
+	file, err := os.ReadFile(c.leaseFile)
+	if err != nil {
+		return err
+	}
+
+	data := string(file)
+	if data == "" {
+		c.logger.Debug().Msg("udhcpc lease file is empty")
+		return nil
+	}
+
+	lease := &Lease{}
+	err = UnmarshalDHCPCLease(lease, string(file))
+	if err != nil {
+		return err
+	}
+
+	isFirstLoad := c.lease == nil
+	c.lease = lease
+
+	if lease.IPAddress == nil {
+		c.logger.Info().
+			Interface("lease", lease).
+			Str("data", string(file)).
+			Msg("udhcpc lease cleared")
+		return nil
+	}
+
+	msg := "udhcpc lease updated"
+	if isFirstLoad {
+		msg = "udhcpc lease loaded"
+	}
+
+	leaseExpiry, err := lease.SetLeaseExpiry()
+	if err != nil {
+		c.logger.Error().Err(err).Msg("failed to get dhcp lease expiry")
+	} else {
+		expiresIn := time.Until(leaseExpiry)
+		c.logger.Info().
+			Interface("expiry", leaseExpiry).
+			Str("expiresIn", expiresIn.String()).
+			Msg("current dhcp lease expiry time calculated")
+	}
+
+	c.onLeaseChange(lease)
+
+	c.logger.Info().
+		Str("ip", lease.IPAddress.String()).
+		Str("leaseTime", lease.LeaseTime.String()).
+		Interface("data", lease).
+		Msg(msg)
+
+	return nil
+}
+
+func (c *DHCPClient) GetLease() *Lease {
+	return c.lease
+}