1 files changed, 168 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/modules/upsd/client.go b/src/go/collectors/go.d.plugin/modules/upsd/client.go
new file mode 100644
index 000000000..a1b8f288e
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/modules/upsd/client.go
@@ -0,0 +1,168 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package upsd
+
+import (
+	"encoding/csv"
+	"errors"
+	"fmt"
+	"strings"
+
+	"github.com/netdata/netdata/go/go.d.plugin/pkg/socket"
+)
+
+const (
+	commandUsername = "USERNAME %s"
+	commandPassword = "PASSWORD %s"
+	commandListUPS  = "LIST UPS"
+	commandListVar  = "LIST VAR %s"
+	commandLogout   = "LOGOUT"
+)
+
+// https://github.com/networkupstools/nut/blob/81fca30b2998fa73085ce4654f075605ff0b9e01/docs/net-protocol.txt#L647
+var errUpsdCommand = errors.New("upsd command error")
+
+type upsUnit struct {
+	name string
+	vars map[string]string
+}
+
+func newUpsdConn(conf Config) upsdConn {
+	return &upsdClient{conn: socket.New(socket.Config{
+		ConnectTimeout: conf.Timeout.Duration(),
+		ReadTimeout:    conf.Timeout.Duration(),
+		WriteTimeout:   conf.Timeout.Duration(),
+		Address:        conf.Address,
+	})}
+}
+
+type upsdClient struct {
+	conn socket.Client
+}
+
+func (c *upsdClient) connect() error {
+	return c.conn.Connect()
+}
+
+func (c *upsdClient) disconnect() error {
+	_, _ = c.sendCommand(commandLogout)
+	return c.conn.Disconnect()
+}
+
+func (c *upsdClient) authenticate(username, password string) error {
+	cmd := fmt.Sprintf(commandUsername, username)
+	resp, err := c.sendCommand(cmd)
+	if err != nil {
+		return err
+	}
+	if resp[0] != "OK" {
+		return errors.New("authentication failed: invalid username")
+	}
+
+	cmd = fmt.Sprintf(commandPassword, password)
+	resp, err = c.sendCommand(cmd)
+	if err != nil {
+		return err
+	}
+	if resp[0] != "OK" {
+		return errors.New("authentication failed: invalid password")
+	}
+
+	return nil
+}
+
+func (c *upsdClient) upsUnits() ([]upsUnit, error) {
+	resp, err := c.sendCommand(commandListUPS)
+	if err != nil {
+		return nil, err
+	}
+
+	var upsNames []string
+
+	for _, v := range resp {
+		if !strings.HasPrefix(v, "UPS ") {
+			continue
+		}
+		parts := splitLine(v)
+		if len(parts) < 2 {
+			continue
+		}
+		name := parts[1]
+		upsNames = append(upsNames, name)
+	}
+
+	var upsUnits []upsUnit
+
+	for _, name := range upsNames {
+		cmd := fmt.Sprintf(commandListVar, name)
+		resp, err := c.sendCommand(cmd)
+		if err != nil {
+			return nil, err
+		}
+
+		ups := upsUnit{
+			name: name,
+			vars: make(map[string]string),
+		}
+
+		upsUnits = append(upsUnits, ups)
+
+		for _, v := range resp {
+			if !strings.HasPrefix(v, "VAR ") {
+				continue
+			}
+			parts := splitLine(v)
+			if len(parts) < 4 {
+				continue
+			}
+			n, v := parts[2], parts[3]
+			ups.vars[n] = v
+		}
+	}
+
+	return upsUnits, nil
+}
+
+func (c *upsdClient) sendCommand(cmd string) ([]string, error) {
+	var resp []string
+	var errMsg string
+	endLine := getEndLine(cmd)
+
+	err := c.conn.Command(cmd+"\n", func(bytes []byte) bool {
+		line := string(bytes)
+		resp = append(resp, line)
+
+		if strings.HasPrefix(line, "ERR ") {
+			errMsg = strings.TrimPrefix(line, "ERR ")
+		}
+
+		return line != endLine && errMsg == ""
+	})
+	if err != nil {
+		return nil, err
+	}
+	if errMsg != "" {
+		return nil, fmt.Errorf("%w: %s (cmd: '%s')", errUpsdCommand, errMsg, cmd)
+	}
+
+	return resp, nil
+}
+
+func getEndLine(cmd string) string {
+	px, _, _ := strings.Cut(cmd, " ")
+
+	switch px {
+	case "USERNAME", "PASSWORD", "VER":
+		return "OK"
+	}
+	return fmt.Sprintf("END %s", cmd)
+}
+
+func splitLine(s string) []string {
+	r := csv.NewReader(strings.NewReader(s))
+	r.Comma = ' '
+
+	parts, _ := r.Read()
+
+	return parts
+}