memcached plugin. Break out metric parsing into it's own func

And unit test it using a sample response string. This will make it
easier to see what other metrics are available to the plugin for adding
future metrics.

plugins/memcached/memcached.go

@@ -28,8 +28,8 @@ var sampleConfig = `
 
 var defaultTimeout = 5 * time.Second
 
-// The list of metrics tha should be calculated
-var sendAsIs = []string{
+// The list of metrics that should be sent
+var sendMetrics = []string{
 	"get_hits",
 	"get_misses",
 	"evictions",
@@ -128,14 +128,36 @@ func (m *Memcached) gatherServer(
 		return err
 	}
 
-	// Read response
+	values, err := parseResponse(rw.Reader)
+	if err != nil {
+		return err
+	}
+
+	// Add server address as a tag
+	tags := map[string]string{"server": address}
+
+	// Process values
+	for _, key := range sendMetrics {
+		if value, ok := values[key]; ok {
+			// Mostly it is the number
+			if iValue, errParse := strconv.ParseInt(value, 10, 64); errParse != nil {
+				acc.Add(key, value, tags)
+			} else {
+				acc.Add(key, iValue, tags)
+			}
+		}
+	}
+	return nil
+}
+
+func parseResponse(r *bufio.Reader) (map[string]string, error) {
 	values := make(map[string]string)
 
 	for {
 		// Read line
-		line, _, errRead := rw.Reader.ReadLine()
+		line, _, errRead := r.ReadLine()
 		if errRead != nil {
-			return errRead
+			return values, errRead
 		}
 		// Done
 		if bytes.Equal(line, []byte("END")) {
@@ -144,28 +166,13 @@ func (m *Memcached) gatherServer(
 		// Read values
 		s := bytes.SplitN(line, []byte(" "), 3)
 		if len(s) != 3 || !bytes.Equal(s[0], []byte("STAT")) {
-			return fmt.Errorf("unexpected line in stats response: %q", line)
+			return values, fmt.Errorf("unexpected line in stats response: %q", line)
 		}
 
 		// Save values
 		values[string(s[1])] = string(s[2])
 	}
-
-	// Add server address as a tag
-	tags := map[string]string{"server": address}
-
-	// Process values
-	for _, key := range sendAsIs {
-		if value, ok := values[key]; ok {
-			// Mostly it is the number
-			if iValue, errParse := strconv.ParseInt(value, 10, 64); errParse != nil {
-				acc.Add(key, value, tags)
-			} else {
-				acc.Add(key, iValue, tags)
-			}
-		}
-	}
-	return nil
+	return values, nil
 }
 
 func init() {

plugins/memcached/memcached_test.go

@@ -1,6 +1,8 @@
 package memcached
 
 import (
+	"bufio"
+	"strings"
 	"testing"
 
 	"github.com/influxdb/telegraf/testutil"
@@ -33,3 +35,126 @@ func TestMemcachedGeneratesMetrics(t *testing.T) {
 		assert.True(t, acc.HasIntValue(metric), metric)
 	}
 }
+
+func TestMemcachedParseMetrics(t *testing.T) {
+	r := bufio.NewReader(strings.NewReader(memcachedStats))
+	values, err := parseResponse(r)
+	require.NoError(t, err, "Error parsing memcached response")
+
+	tests := []struct {
+		key   string
+		value string
+	}{
+		{"pid", "23235"},
+		{"uptime", "194"},
+		{"time", "1449174679"},
+		{"version", "1.4.14 (Ubuntu)"},
+		{"libevent", "2.0.21-stable"},
+		{"pointer_size", "64"},
+		{"rusage_user", "0.000000"},
+		{"rusage_system", "0.007566"},
+		{"curr_connections", "5"},
+		{"total_connections", "6"},
+		{"connection_structures", "6"},
+		{"reserved_fds", "20"},
+		{"cmd_get", "0"},
+		{"cmd_set", "0"},
+		{"cmd_flush", "0"},
+		{"cmd_touch", "0"},
+		{"get_hits", "0"},
+		{"get_misses", "0"},
+		{"delete_misses", "0"},
+		{"delete_hits", "0"},
+		{"incr_misses", "0"},
+		{"incr_hits", "0"},
+		{"decr_misses", "0"},
+		{"decr_hits", "0"},
+		{"cas_misses", "0"},
+		{"cas_hits", "0"},
+		{"cas_badval", "0"},
+		{"touch_hits", "0"},
+		{"touch_misses", "0"},
+		{"auth_cmds", "0"},
+		{"auth_errors", "0"},
+		{"bytes_read", "7"},
+		{"bytes_written", "0"},
+		{"limit_maxbytes", "67108864"},
+		{"accepting_conns", "1"},
+		{"listen_disabled_num", "0"},
+		{"threads", "4"},
+		{"conn_yields", "0"},
+		{"hash_power_level", "16"},
+		{"hash_bytes", "524288"},
+		{"hash_is_expanding", "0"},
+		{"expired_unfetched", "0"},
+		{"evicted_unfetched", "0"},
+		{"bytes", "0"},
+		{"curr_items", "0"},
+		{"total_items", "0"},
+		{"evictions", "0"},
+		{"reclaimed", "0"},
+	}
+
+	for _, test := range tests {
+		value, ok := values[test.key]
+		if !ok {
+			t.Errorf("Did not find key for metric %s in values", test.key)
+			continue
+		}
+		if value != test.value {
+			t.Errorf("Metric: %s, Expected: %s, actual: %s",
+				test.key, test.value, value)
+		}
+	}
+}
+
+var memcachedStats = `STAT pid 23235
+STAT uptime 194
+STAT time 1449174679
+STAT version 1.4.14 (Ubuntu)
+STAT libevent 2.0.21-stable
+STAT pointer_size 64
+STAT rusage_user 0.000000
+STAT rusage_system 0.007566
+STAT curr_connections 5
+STAT total_connections 6
+STAT connection_structures 6
+STAT reserved_fds 20
+STAT cmd_get 0
+STAT cmd_set 0
+STAT cmd_flush 0
+STAT cmd_touch 0
+STAT get_hits 0
+STAT get_misses 0
+STAT delete_misses 0
+STAT delete_hits 0
+STAT incr_misses 0
+STAT incr_hits 0
+STAT decr_misses 0
+STAT decr_hits 0
+STAT cas_misses 0
+STAT cas_hits 0
+STAT cas_badval 0
+STAT touch_hits 0
+STAT touch_misses 0
+STAT auth_cmds 0
+STAT auth_errors 0
+STAT bytes_read 7
+STAT bytes_written 0
+STAT limit_maxbytes 67108864
+STAT accepting_conns 1
+STAT listen_disabled_num 0
+STAT threads 4
+STAT conn_yields 0
+STAT hash_power_level 16
+STAT hash_bytes 524288
+STAT hash_is_expanding 0
+STAT expired_unfetched 0
+STAT evicted_unfetched 0
+STAT bytes 0
+STAT curr_items 0
+STAT total_items 0
+STAT evictions 0
+STAT reclaimed 0
+END
+`