add metric for open files

Makefile

@@ -1,9 +1,9 @@
 GIT_COMMIT = $(shell git rev-parse --short HEAD)
 GIT_STATUS = $(shell test -n "`git status --porcelain`" && echo "+CHANGES")
-BUILD_CMD = go build -a -ldflags "-X main.GITCOMMIT $(GIT_COMMIT)$(GIT_STATUS)"
+BUILD_CMD = go build -ldflags "-X main.GITCOMMIT $(GIT_COMMIT)$(GIT_STATUS)"
 
 default: clean test all
-	./bin/metrix --cpu --memory --net --df --disk --processes
+	./bin/metrix --cpu --memory --net --df --disk --processes --files
 
 wip: ctags test
 
@@ -22,7 +22,7 @@ test:
 
 jenkins: clean install_dependencies test all
 	PROC_ROOT=./fixtures ./bin/metrix --loadavg --disk --memory --processes --cpu
-	./bin/metrix --loadavg --disk --memory --processes --cpu --keys
+	./bin/metrix --loadavg --disk --memory --processes --cpu --keys --files
 
 all:
 	$(BUILD_CMD) -o bin/metrix

README.md

@@ -102,6 +102,11 @@ All metrics are tagged with `file_system` and `mounted_on` when writing to OpenT
     net.ip.InOctets
     net.ip.OutOctets
 
+### Open Files (fetched with lsof)
+
+     $ ./bin/metrix --files --keys
+     files.Open
+
 ### Process
 
 All metrics are tagged with `pid`, parent pid (`ppid`), `name` and raw `comm` value of the process when writing to OpenTSDB.

files.go

@@ -0,0 +1,62 @@
+package main
+
+import (
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+const (
+	FILES = "files"
+	FILES_OPEN = "Open"
+)
+
+var LSOF_CMD = `lsof | tail -n +2 | tr -s " " "` + "\t" + `" | cut -f 1,2`
+
+func init() {
+	parser.Add(FILES, "true", "Collect open files")
+}
+
+type Files struct {
+	RawStatus []byte
+}
+
+func (files *Files) fetch() (b []byte, e error) {
+	if len(files.RawStatus) == 0 {
+		args := []string { "-c" }
+		args = append(args, LSOF_CMD)
+		files.RawStatus, _ = exec.Command("bash", args...).Output()
+		if len(files.RawStatus) == 0 {
+			return b, fmt.Errorf("lsof returned empty result")
+		}
+	}
+	return files.RawStatus, nil
+}
+
+func (f *Files) Collect(col *MetricsCollection) error {
+	b, e := f.fetch()
+	if e != nil {
+		return e
+	}
+	stats := map[string]int64{}
+	for _, line := range strings.Split(string(b), "\n") {
+		stats[line]++
+	}
+	for k, v := range stats {
+		chunks := strings.SplitN(k, "\t", 2)
+		if len(chunks) == 2 {
+			name, pid := chunks[0], chunks[1]
+			tags := map[string]string{"name": NormalizeProcessName(name), "pid": pid}
+			col.AddWithTags(FILES_OPEN, v, tags)
+		}
+	}
+	return nil
+}
+
+func (f *Files) Keys() []string {
+	return []string{FILES_OPEN}
+}
+
+func (f *Files) Prefix() string {
+	return FILES
+}

files_test.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestFiles(t *testing.T) {
+	files := &Files{RawStatus: readFile("fixtures/lsof.txt")}
+	assert.Equal(t, files.Prefix(), "files")
+	assert.NotEmpty(t, files.Keys())
+
+	mh := new(MetricHandler)
+	stats, _ := mh.Collect(files)
+	assert.True(t, len(stats) > 4)
+	assert.Equal(t, len(stats), 74)
+
+	names := map[string]int{}
+	for _, s := range stats {
+		names[s.Tags["name"]]++
+	}
+	assert.Equal(t, names["kworker/0"], 0)
+	assert.Equal(t, names["kworker"], 8)
+}
+
+func TestParseLsofOutput(t *testing.T) {
+	return
+}