Merge pull request #40 from mysteriumnetwork/server-byte-count

Added a middleware for server side statistics for sessions

openvpn/middlewares/server/bytecount/bytecount.go

@@ -0,0 +1,98 @@
+/*
+ * Copyright (C) 2019 The "MysteriumNetwork/go-openvpn" Authors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package bytecount
+
+import (
+	"fmt"
+	"regexp"
+	"strconv"
+
+	"github.com/mysteriumnetwork/go-openvpn/openvpn/management"
+)
+
+var rule = regexp.MustCompile("^>BYTECOUNT_CLI:([0-9]*),([0-9]*),([0-9]*)$")
+
+// SessionByteChangeHandler is the callback we call with the session byte count
+type SessionByteChangeHandler func(SessionByteCount)
+
+// SessionByteCount represents
+type SessionByteCount struct {
+	ClientID, BytesIn, BytesOut int
+}
+
+// Middleware reports the different session byte counts
+type Middleware struct {
+	handler        SessionByteChangeHandler
+	updateInterval int
+}
+
+// NewMiddleware returns a new instance of the middleware
+func NewMiddleware(h SessionByteChangeHandler, updateInterval int) *Middleware {
+	return &Middleware{
+		handler:        h,
+		updateInterval: updateInterval,
+	}
+}
+
+// Start starts the middleware
+func (m *Middleware) Start(cw management.CommandWriter) error {
+	_, err := cw.SingleLineCommand("bytecount %v", m.updateInterval)
+	return err
+}
+
+// Stop stops the middleware
+func (m *Middleware) Stop(cw management.CommandWriter) error {
+	_, err := cw.SingleLineCommand("bytecount %v", 0)
+	return err
+}
+
+// ConsumeLine handles the given openvpn management line
+func (m *Middleware) ConsumeLine(line string) (consumed bool, err error) {
+	if !rule.MatchString(line) {
+		return false, nil
+	}
+
+	match := rule.FindStringSubmatch(line)
+
+	if len(match) != 4 {
+		return false, fmt.Errorf("wrong match length for %q. got len = %v, expected %v", line, len(match), 4)
+	}
+
+	clientID, err := strconv.Atoi(match[1])
+	if err != nil {
+		return false, fmt.Errorf("could not parse clientID from match[1]: %q", match[1])
+	}
+
+	bytesIn, err := strconv.Atoi(match[2])
+	if err != nil {
+		return false, fmt.Errorf("could not parse clientID from match[2]: %q", match[2])
+	}
+
+	bytesOut, err := strconv.Atoi(match[3])
+	if err != nil {
+		return false, fmt.Errorf("could not parse clientID from match[3]: %q", match[3])
+	}
+
+	m.handler(SessionByteCount{
+		ClientID: clientID,
+		BytesIn:  bytesIn,
+		BytesOut: bytesOut,
+	})
+
+	return true, nil
+}

openvpn/middlewares/server/bytecount/bytecount_test.go

@@ -0,0 +1,60 @@
+/*
+ * Copyright (C) 2019 The "MysteriumNetwork/go-openvpn" Authors.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package bytecount
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type mockHandler struct {
+	sbc SessionByteCount
+}
+
+func (mh *mockHandler) Handle(s SessionByteCount) {
+	mh.sbc = s
+}
+
+func Test_ConsumesOKLine(t *testing.T) {
+	statsRecorder := &mockHandler{}
+	middleware := NewMiddleware(statsRecorder.Handle, 1)
+	consumed, err := middleware.ConsumeLine(">BYTECOUNT_CLI:1,2,3")
+	assert.Nil(t, err)
+	assert.True(t, consumed)
+	assert.Equal(t, 1, statsRecorder.sbc.ClientID)
+	assert.Equal(t, 2, statsRecorder.sbc.BytesIn)
+	assert.Equal(t, 3, statsRecorder.sbc.BytesOut)
+}
+
+func Test_IgnoresMalformedLines(t *testing.T) {
+	badLines := []string{
+		">BYTECOUNT_CLI:asdasd,2,3",
+		">BYTECOUNT_CLI",
+		"whatever",
+		"BYTECOUNT_CLI:1,2,3",
+	}
+	for _, v := range badLines {
+		statsRecorder := &mockHandler{}
+		middleware := NewMiddleware(statsRecorder.Handle, 1)
+		consumed, err := middleware.ConsumeLine(v)
+		assert.Nil(t, err)
+		assert.False(t, consumed)
+		assert.EqualValues(t, SessionByteCount{}, statsRecorder.sbc)
+	}
+}