first working version

pkg/controller/loadbalancer.go

@@ -0,0 +1,161 @@
+package controller
+
+import (
+	"context"
+	"os/exec"
+	"time"
+
+	"git.giftfish.de/ston1th/haproxy-lb/pkg/api"
+	"git.giftfish.de/ston1th/haproxy-lb/pkg/cluster"
+	"git.giftfish.de/ston1th/haproxy-lb/pkg/config"
+	"git.giftfish.de/ston1th/haproxy-lb/pkg/db"
+	"git.giftfish.de/ston1th/haproxy-lb/pkg/haproxy"
+	"git.giftfish.de/ston1th/haproxy-lb/pkg/vip"
+	"github.com/go-logr/logr"
+)
+
+func NewLBController(cfg *config.Config, srv *api.Server, log logr.Logger) (callbacks cluster.Callbacks, err error) {
+	n, err := vip.NewNetworkWithLabel(cfg.VIP.Interface, cfg.VIP.Label)
+	if err != nil {
+		return
+	}
+	ha, err := haproxy.NewHAProxyManager(cfg.HAProxyConfig, cfg.HAProxyService)
+	if err != nil {
+		return
+	}
+
+	callbacks = cluster.Callbacks{
+		Leader: func(ctx context.Context, cc cluster.CallbackContext) {
+			db := db.New(cc)
+			cc.V(2).Info("starting haproxy", "service", cfg.HAProxyService)
+			err := ha.Start(ctx)
+			if err != nil {
+				cc.Error(err, "error starting haproxy")
+				cc.Fatal(err)
+				return
+			}
+			err = srv.UpdateDB(db)
+			if err != nil {
+				cc.Error(err, "error initialising api server as leader")
+				cc.Fatal(err)
+				return
+			}
+			t := time.NewTicker(time.Second * 10)
+			if cfg.LeaderHook != "" {
+				go func() {
+					err := exec.CommandContext(ctx, cfg.LeaderHook).Run()
+					if err != nil {
+						cc.Error(err, "error running hook", "leaderHook", cfg.LeaderHook)
+					}
+				}()
+			}
+			for {
+				cc.Info("leading", "id", cc.ID())
+				ips, err := db.GetDeletedIPs()
+				if err != nil && err != cluster.ErrPrefixNotFound {
+					cc.Error(err, "error reading deleted ips list")
+					<-t.C
+					continue
+				}
+				deleteIPs(cc, n, ips)
+
+				ips, err = db.GetIPs()
+				if err != nil && err != cluster.ErrPrefixNotFound {
+					cc.Error(err, "error reading ips list")
+					<-t.C
+					continue
+				}
+				addIPs(cc, n, ips)
+
+				lbs, err := db.GetLBs("")
+				if err != nil && err != cluster.ErrPrefixNotFound {
+					cc.Error(err, "error reading lb list")
+					<-t.C
+					continue
+				}
+				lbcfg, err := haproxy.NewConfig(lbs)
+				if err != nil {
+					cc.Error(err, "error reading haproxy config")
+					<-t.C
+					continue
+				}
+				err = ha.UpdateConfig(ctx, lbcfg)
+				if err != nil {
+					cc.Error(err, "error updating haproxy config")
+					<-t.C
+					continue
+				}
+				select {
+				case <-ctx.Done():
+					t.Stop()
+					deleteIPs(cc, n, ips)
+					cc.V(2).Info("stopping haproxy", "service", cfg.HAProxyService)
+					err = ha.Stop(context.Background())
+					if err != nil {
+						cc.Error(err, "error stopping haproxy")
+					}
+					cc.Info("leading canceled", "id", cc.ID())
+					return
+				case <-t.C:
+				}
+			}
+		},
+		Follower: func(ctx context.Context, cc cluster.CallbackContext) {
+			db := db.New(cc)
+			err := srv.UpdateDB(db)
+			if err != nil {
+				cc.Error(err, "error initialising api server as follower")
+				cc.Fatal(err)
+				return
+			}
+			t := time.NewTicker(time.Second * 10)
+			if cfg.FollowerHook != "" {
+				go func() {
+					err := exec.CommandContext(ctx, cfg.FollowerHook).Run()
+					if err != nil {
+						cc.Error(err, "error running hook", "followerHook", cfg.FollowerHook)
+					}
+				}()
+			}
+			for {
+				cc.Info("following", "id", cc.ID())
+				select {
+				case <-ctx.Done():
+					t.Stop()
+					cc.Info("following canceled", "id", cc.ID())
+					return
+				case <-t.C:
+				}
+			}
+		},
+		Cleanup: func(ctx context.Context, cc cluster.CallbackContext) {
+			db := db.New(cc)
+			ips, err := db.GetIPs()
+			if err != nil {
+				return
+			}
+			deleteIPs(cc, n, ips)
+		},
+	}
+	return
+}
+
+func addIPs(log logr.Logger, n *vip.Network, cidrs []string) error {
+	for _, cidr := range cidrs {
+		err := n.AddIP(cidr)
+		if err != nil {
+			log.Error(err, "adding ip", "interface", n.Interface(), "ip", cidr)
+		}
+	}
+	return nil
+}
+
+func deleteIPs(log logr.Logger, n *vip.Network, cidrs []string) error {
+	for _, cidr := range cidrs {
+		err := n.DeleteIP(cidr)
+		if err != nil {
+			log.Error(err, "deleting ip", "interface", n.Interface(), "ip", cidr)
+		}
+	}
+	return nil
+}