Add mysql plugin

plugins/mysql/mysql_test.go

@@ -0,0 +1,68 @@
+package mysql
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/influxdb/tivan/testutil"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMysqlGeneratesMetrics(t *testing.T) {
+	m := &Mysql{
+		Servers: []*Server{
+			{
+				Address: "",
+			},
+		},
+	}
+
+	var acc testutil.Accumulator
+
+	err := m.Gather(&acc)
+	require.NoError(t, err)
+
+	prefixes := []struct {
+		prefix string
+		count  int
+	}{
+		{"mysql_commands", 141},
+		{"mysql_handler", 18},
+		{"mysql_bytes", 2},
+		{"mysql_innodb", 51},
+		{"mysql_threads", 4},
+	}
+
+	intMetrics := []string{
+		"mysql_queries",
+		"mysql_slow_queries",
+	}
+
+	for _, prefix := range prefixes {
+		var count int
+
+		for _, p := range acc.Points {
+			if strings.HasPrefix(p.Name, prefix.prefix) {
+				count++
+			}
+		}
+
+		assert.Equal(t, prefix.count, count)
+	}
+
+	for _, metric := range intMetrics {
+		assert.True(t, acc.HasIntValue(metric))
+	}
+}
+
+func TestMysqlDefaultsToLocal(t *testing.T) {
+	m := &Mysql{}
+
+	var acc testutil.Accumulator
+
+	err := m.Gather(&acc)
+	require.NoError(t, err)
+
+	assert.True(t, len(acc.Points) > 0)
+}