procstat: Add user, pidfile, pattern & exe tags

CHANGELOG.md

@@ -37,6 +37,7 @@ based on _prefix_ in addition to globs. This means that a filter like
 - [#889](https://github.com/influxdata/telegraf/pull/889): Improved MySQL plugin. Thanks @maksadbek!
 - [#1060](https://github.com/influxdata/telegraf/pull/1060): TTL metrics added to MongoDB input plugin
 - [#1056](https://github.com/influxdata/telegraf/pull/1056): Don't allow inputs to overwrite host tags.
+- [#1035](https://github.com/influxdata/telegraf/issues/1035): Add `user`, `exe`, `pidfile` tags to procstat plugin.
 
 ### Bugfixes
 

plugins/inputs/procstat/procstat.go

@@ -21,12 +21,16 @@ type Procstat struct {
 	Prefix  string
 	User    string
 
+	// pidmap maps a pid to a process object, so we don't recreate every gather
 	pidmap map[int32]*process.Process
+	// tagmap maps a pid to a map of tags for that pid
+	tagmap map[int32]map[string]string
 }
 
 func NewProcstat() *Procstat {
 	return &Procstat{
 		pidmap: make(map[int32]*process.Process),
+		tagmap: make(map[int32]map[string]string),
 	}
 }
 
@@ -61,8 +65,8 @@ func (p *Procstat) Gather(acc telegraf.Accumulator) error {
 		log.Printf("Error: procstat getting process, exe: [%s]	pidfile: [%s] pattern: [%s] user: [%s] %s",
 			p.Exe, p.PidFile, p.Pattern, p.User, err.Error())
 	} else {
-		for _, proc := range p.pidmap {
-			p := NewSpecProcessor(p.Prefix, acc, proc)
+		for pid, proc := range p.pidmap {
+			p := NewSpecProcessor(p.Prefix, acc, proc, p.tagmap[pid])
 			p.pushMetrics()
 		}
 	}
@@ -103,45 +107,50 @@ func (p *Procstat) getAllPids() ([]int32, error) {
 	var err error
 
 	if p.PidFile != "" {
-		pids, err = pidsFromFile(p.PidFile)
+		pids, err = p.pidsFromFile()
 	} else if p.Exe != "" {
-		pids, err = pidsFromExe(p.Exe)
+		pids, err = p.pidsFromExe()
 	} else if p.Pattern != "" {
-		pids, err = pidsFromPattern(p.Pattern)
+		pids, err = p.pidsFromPattern()
 	} else if p.User != "" {
-		pids, err = pidsFromUser(p.User)
+		pids, err = p.pidsFromUser()
 	} else {
-		err = fmt.Errorf("Either exe, pid_file or pattern has to be specified")
+		err = fmt.Errorf("Either exe, pid_file, user, or pattern has to be specified")
 	}
 
 	return pids, err
 }
 
-func pidsFromFile(file string) ([]int32, error) {
+func (p *Procstat) pidsFromFile() ([]int32, error) {
 	var out []int32
 	var outerr error
-	pidString, err := ioutil.ReadFile(file)
+	pidString, err := ioutil.ReadFile(p.PidFile)
 	if err != nil {
-		outerr = fmt.Errorf("Failed to read pidfile '%s'. Error: '%s'", file, err)
+		outerr = fmt.Errorf("Failed to read pidfile '%s'. Error: '%s'",
+			p.PidFile, err)
 	} else {
 		pid, err := strconv.Atoi(strings.TrimSpace(string(pidString)))
 		if err != nil {
 			outerr = err
 		} else {
 			out = append(out, int32(pid))
+			p.tagmap[int32(pid)] = map[string]string{
+				"pidfile": p.PidFile,
+				"pid":     string(pidString),
+			}
 		}
 	}
 	return out, outerr
 }
 
-func pidsFromExe(exe string) ([]int32, error) {
+func (p *Procstat) pidsFromExe() ([]int32, error) {
 	var out []int32
 	var outerr error
 	bin, err := exec.LookPath("pgrep")
 	if err != nil {
 		return out, fmt.Errorf("Couldn't find pgrep binary: %s", err)
 	}
-	pgrep, err := exec.Command(bin, exe).Output()
+	pgrep, err := exec.Command(bin, p.Exe).Output()
 	if err != nil {
 		return out, fmt.Errorf("Failed to execute %s. Error: '%s'", bin, err)
 	} else {
@@ -150,6 +159,10 @@ func pidsFromExe(exe string) ([]int32, error) {
 			ipid, err := strconv.Atoi(pid)
 			if err == nil {
 				out = append(out, int32(ipid))
+				p.tagmap[int32(ipid)] = map[string]string{
+					"exe": p.Exe,
+					"pid": pid,
+				}
 			} else {
 				outerr = err
 			}
@@ -158,14 +171,14 @@ func pidsFromExe(exe string) ([]int32, error) {
 	return out, outerr
 }
 
-func pidsFromPattern(pattern string) ([]int32, error) {
+func (p *Procstat) pidsFromPattern() ([]int32, error) {
 	var out []int32
 	var outerr error
 	bin, err := exec.LookPath("pgrep")
 	if err != nil {
 		return out, fmt.Errorf("Couldn't find pgrep binary: %s", err)
 	}
-	pgrep, err := exec.Command(bin, "-f", pattern).Output()
+	pgrep, err := exec.Command(bin, "-f", p.Pattern).Output()
 	if err != nil {
 		return out, fmt.Errorf("Failed to execute %s. Error: '%s'", bin, err)
 	} else {
@@ -174,6 +187,10 @@ func pidsFromPattern(pattern string) ([]int32, error) {
 			ipid, err := strconv.Atoi(pid)
 			if err == nil {
 				out = append(out, int32(ipid))
+				p.tagmap[int32(ipid)] = map[string]string{
+					"pattern": p.Pattern,
+					"pid":     pid,
+				}
 			} else {
 				outerr = err
 			}
@@ -182,14 +199,14 @@ func pidsFromPattern(pattern string) ([]int32, error) {
 	return out, outerr
 }
 
-func pidsFromUser(user string) ([]int32, error) {
+func (p *Procstat) pidsFromUser() ([]int32, error) {
 	var out []int32
 	var outerr error
 	bin, err := exec.LookPath("pgrep")
 	if err != nil {
 		return out, fmt.Errorf("Couldn't find pgrep binary: %s", err)
 	}
-	pgrep, err := exec.Command(bin, "-u", user).Output()
+	pgrep, err := exec.Command(bin, "-u", p.User).Output()
 	if err != nil {
 		return out, fmt.Errorf("Failed to execute %s. Error: '%s'", bin, err)
 	} else {
@@ -198,6 +215,10 @@ func pidsFromUser(user string) ([]int32, error) {
 			ipid, err := strconv.Atoi(pid)
 			if err == nil {
 				out = append(out, int32(ipid))
+				p.tagmap[int32(ipid)] = map[string]string{
+					"user": p.User,
+					"pid":  pid,
+				}
 			} else {
 				outerr = err
 			}

plugins/inputs/procstat/procstat_test.go

@@ -25,6 +25,7 @@ func TestGather(t *testing.T) {
 		PidFile: file.Name(),
 		Prefix:  "foo",
 		pidmap:  make(map[int32]*process.Process),
+		tagmap:  make(map[int32]map[string]string),
 	}
 	p.Gather(&acc)
 	assert.True(t, acc.HasFloatField("procstat", "foo_cpu_time_user"))

plugins/inputs/procstat/spec_processor.go

@@ -36,9 +36,8 @@ func NewSpecProcessor(
 	prefix string,
 	acc telegraf.Accumulator,
 	p *process.Process,
+	tags map[string]string,
 ) *SpecProcessor {
-	tags := make(map[string]string)
-	tags["pid"] = fmt.Sprintf("%v", p.Pid)
 	if name, err := p.Name(); err == nil {
 		tags["process_name"] = name
 	}