capricious flag/config file changes

README.md

@@ -12,9 +12,12 @@ If you think that this may be useful and have any
 questions/suggestions, feel free to contact me at vc5lb@proton.me or
 raise a GitHub issue.
 
-There has been a bt of an overhaul on the elasticsearch logging
-schema> I can't imagine that this is being used much yet, but
-something to be aware of if you are using it.
+## NB:
+
+In a hopefully final bout of capriciousness I have put the primary
+IPv4 address back as the mandatory first command line argument. Other
+parameters which cannot be changed after initialisation have been
+removed from the config file and are now flags.
 
 ## Quickstart
 

cmd/main.go

@@ -40,11 +40,9 @@ func main() {
 
 	const FACILITY = "vc5"
 
-	// mandatory - will likely make this the 1st argument again
-	addr := flag.String("a", "", "Primary IPv4 address (used for BGP router ID probe source address if VLANs not used)")
-
 	// commonly used flags
-	bgp := flag.Bool("b", false, "Enable BGP listener on port 179")
+	learn := flag.Uint("l", 0, "Learn; wait for this many seconds before advertising VIPs (for multicast flow state adverts)")
+	listen := flag.Bool("b", false, "Enable BGP listener on port 179")
 	native := flag.Bool("n", false, "Use native mode XDP; better performance on network cards that support it")
 	hostid := flag.String("i", "", "Host ID for logging")
 	webroot := flag.String("r", "", "Webserver root directory to override built-in documents")
@@ -54,9 +52,9 @@ func main() {
 	// somewhat more esoteric options
 	asn := flag.Uint("A", 0, "Autonomous System Number to enable loopback BGP")
 	delay := flag.Uint("D", 0, "Delay between initialisaton of interfaces (to prevent bond from flapping)")
-	flows := flag.Uint("F", 0, "Set maximum number of flows")                      // experimental - may change
-	cmd_path := flag.String("C", "", "Command channel path")                       // experimental - may change
-	hardfail := flag.Bool("H", false, "Hard fail on balancer configuration error") // experimental - may change
+	flows := flag.Uint("F", 0, "Set maximum number of flows")
+	cmd_path := flag.String("C", "", "Command channel path")
+	hardfail := flag.Bool("H", false, "Hard fail on balancer configuration error")
 
 	// Best not to mess with these
 	socket := flag.String("S", "/var/run/vc5ns", "Socket for communication with proxy in network namespace")
@@ -77,8 +75,9 @@ func main() {
 		return
 	}
 
-	file := args[0]
-	nics := args[1:]
+	addr := args[0]
+	file := args[1]
+	nics := args[2:]
 
 	config, err := vc5.Load(file)
 
@@ -87,11 +86,7 @@ func main() {
 	}
 
 	if *hostid == "" {
-		*hostid = *addr
-	}
-
-	if *hostid == "" {
-		*hostid = "vc5"
+		*hostid = addr
 	}
 
 	logs := vc5.NewLogger(*hostid, config.LoggingConfig())
@@ -100,7 +95,7 @@ func main() {
 		logs.Fatal(FACILITY, "args", KV{"error.message": "No interfaces defined"})
 	}
 
-	address := netip.MustParseAddr(*addr)
+	address := netip.MustParseAddr(addr)
 
 	if !address.Is4() {
 		logs.Fatal(FACILITY, "args", KV{"error.message": "Address is not IPv4: " + address.String()})
@@ -126,8 +121,7 @@ func main() {
 	// getting into an error state - the manager will accept the
 	// connection but then quietly drop it after ten seconds or
 	// so. This seems to keep the peer happy.
-	//err = bgpListener(logs.Sub("bgp"))
-	if *bgp {
+	if *listen {
 		err = bgpListener(logs)
 		if err != nil {
 			log.Fatal(err)
@@ -169,6 +163,9 @@ func main() {
 	// Short delay to let interfaces quiesce after loading XDP
 	time.Sleep(5 * time.Second)
 
+	// Add a short delay on return to allow BGP, etc to cleanly exit
+	defer time.Sleep(5 * time.Second)
+
 	// Create a balancer instance - this implements interface methods
 	// (configuration changes, stats requests, etc). which are called
 	// by the manager object (which handles the main event loop)
@@ -194,6 +191,7 @@ func main() {
 	manager := vc5.Manager{
 		Balancer:    balancer,
 		Logs:        logs,
+		Learn:       *learn,
 		NAT:         nat(client),             // We use a NAT method and a custom probe function
 		Prober:      prober(client, *socket), // to run checks from the inside network namespace
 		RouterID:    routerID,                // BGP router ID to use to speak to peers

config.go

@@ -29,7 +29,7 @@ import (
 	"os"
 	"regexp"
 	"strconv"
-	"time"
+	//"time"
 
 	"github.com/davidcoles/cue"
 	"github.com/davidcoles/cue/bgp"
@@ -85,8 +85,8 @@ type Config struct {
 	Services services                  `json:"services,omitempty"`
 	VLANs    map[uint16]Prefix         `json:"vlans,omitempty"` // VLAN ID to subnet mappings
 	BGP      map[string]bgp.Parameters `json:"bgp,omitempty"`   // BGP peers
-	Learn    time.Duration             `json:"learn,omitempty"`
-	Logging  Logging_                  `json:"logging,omitempty"`
+	//Learn    time.Duration             `json:"learn,omitempty"`
+	Logging Logging_ `json:"logging,omitempty"`
 }
 
 func (c *Config) LoggingConfig() Logging {

manager.go

@@ -49,6 +49,7 @@ type Manager struct {
 	RouterID    [4]byte
 	WebListener net.Listener
 	Interval    uint8
+	Learn       uint
 
 	Address netip.Addr
 	SNI     bool
@@ -84,6 +85,11 @@ func (m *Manager) Manage(ctx context.Context, cfg *Config) error {
 
 	m.config = cfg
 
+	learn := time.Duration(m.Learn)
+	if learn == 0 {
+		learn = 1
+	}
+
 	start := time.Now()
 	F := "vc5"
 
@@ -146,7 +152,7 @@ func (m *Manager) Manage(ctx context.Context, cfg *Config) error {
 
 	// advertise VIPs via BGP
 	go func() {
-		timer := time.NewTimer(m.config.Learn * time.Second)
+		timer := time.NewTimer(learn * time.Second)
 		ticker := time.NewTicker(5 * time.Second)
 		services := m.Director.Status()