initial commit

pkg/haproxy/haproxy.go

@@ -0,0 +1,67 @@
+package haproxy
+
+import (
+	"context"
+	"io/ioutil"
+	"os"
+	"sync"
+	"text/template"
+)
+
+type ServiceManager interface {
+	Reload()
+}
+
+type HAProxyManager struct {
+	sync.Mutex
+
+	configFile     string
+	serviceManager ServiceManager
+	template       *template.Template
+}
+
+func NewHAProxyManager(configFile string) (*HAProxyManager, error) {
+	t, err := template.New("haproxy").Parse(haproxyTemplate)
+	if err != nil {
+		return nil, err
+	}
+	return &HAProxyManager{
+		configFile:     configFile,
+		serviceManager: NewSystemdManager("haproxy"),
+		template:       t,
+	}, nil
+}
+
+func (ha *HAProxyManager) checkConfig(ctx context.Context, configFile string) error {
+	return exec.CommandContext(ctx, "haproxy", "-c", "-f", configFile).Run()
+}
+
+func (ha *HAProxyManager) UpdateConfig(ctx context.Context, lbs []config.LoadBalancer) error {
+	ha.Lock()
+	defer ha.Unlock()
+	tmp, err := ioutil.TempFile(os.TempDir(), "haproxy_")
+	if err != nil {
+		return err
+	}
+	defer tmp.Close()
+	defer os.Remove(tmp.Name())
+	err = ha.template.Execute(tmp, lbs)
+	if err != nil {
+		return err
+	}
+	err = ha.checkConfig(ctx, tmp.Name())
+	if err != nil {
+		return err
+	}
+	file, err := os.OpenFile(ha.configFile, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
+	if err != nil {
+		return err
+	}
+	err = ha.template.Execute(file, lbs)
+	if err != nil {
+		file.Close()
+		return err
+	}
+	file.Close()
+	return ha.serviceManager.Reload()
+}

pkg/haproxy/systemd.go

@@ -0,0 +1,20 @@
+package haproxy
+
+import (
+	"context"
+	"os/exec"
+)
+
+const systemctl = "systemctl"
+
+type SystemdManager struct {
+	service string
+}
+
+func NewSystemdManager(service string) *SystemdManager {
+	return &SystemdManager{service}
+}
+
+func (sm *SystemdManager) Reload(ctx context.Context) error {
+	return exec.CommandContext(ctx, systemctl, "reload", sm.service).Run()
+}

pkg/haproxy/template.go

@@ -0,0 +1,43 @@
+package haproxy
+
+const haproxyConfigTemplate = `global
+  daemon
+  chroot /var/lib/haproxy
+  user haproxy
+  group haproxy
+  maxconn 5000
+defaults
+  mode tcp
+  log global
+  retries 2
+  timeout connect 3000ms
+  timeout server 5000ms
+  timeout client 5000ms
+  timeout tunnel 3600s
+  timeout check 10s
+{{ range $item := . -}}
+{{ range $port := $item.Ports -}}
+frontend fr_{{ $item.Name }}_{{ $port.Port }}
+  bind {{ $item.IP }}:{{ $port.Port }}
+  {{ range $opt := $item.Options.Frontend -}}
+  option {{ $opt }}
+  {{ end -}}
+  # option tcplog
+  # option splice-request
+  default_backend ba_{{ $item.Name }}_{{ $port.Port }}
+backend ba_{{ $item.Name }}_{{ $port.Port }}
+  balance roundrobin
+  {{ range $opt := $item.Options.Backend -}}
+  option {{ $opt }}
+  {{ end -}}
+  # option splice-response
+  # option httpchk GET /
+  default-server inter 3s downinter 10s fall 2 rise 2 on-marked-down shutdown-sessions {{ $item.Options.DefaultServer }}
+  # send-proxy-v2
+  # check-send-proxy
+  # port <healthCheckNodePort>
+  {{ range $srv := $port.Servers -}}
+  server {{ $srv.Name }} {{ $srv.IP }}:{{ $srv.Port }} check
+  {{ end -}}
+{{ end -}}
+{{ end -}}`