Add systemd unit pid and cgroup matching to procstat (#3459)

This commit is contained in:
Patrick Hemmer 2017-11-13 13:59:27 -05:00 committed by Daniel Nelson
parent 084f7dc53b
commit 2323d9ae48
2 changed files with 75 additions and 5 deletions

View File

@ -6,11 +6,11 @@ The procstat plugin can be used to monitor system resource usage by an
individual process using their /proc data.
Processes can be specified either by pid file, by executable name, by command
line pattern matching, or by username (in this order or priority. Procstat
plugin will use `pgrep` when executable name is provided to obtain the pid.
Procstat plugin will transmit IO, memory, cpu, file descriptor related
measurements for every process specified. A prefix can be set to isolate
individual process specific measurements.
line pattern matching, by username, by systemd unit name, or by cgroup name/path
(in this order or priority). Procstat plugin will use `pgrep` when executable
name is provided to obtain the pid. Procstat plugin will transmit IO, memory,
cpu, file descriptor related measurements for every process specified. A prefix
can be set to isolate individual process specific measurements.
The plugin will tag processes according to how they are specified in the configuration. If a pid file is used, a "pidfile" tag will be generated.
On the other hand, if an executable is used an "exe" tag will be generated. Possible tag names:
@ -19,6 +19,8 @@ On the other hand, if an executable is used an "exe" tag will be generated. Poss
* exe
* pattern
* user
* systemd_unit
* cgroup
Additionally the plugin will tag processes by their PID (pid_tag = true in the config) and their process name:

View File

@ -1,7 +1,10 @@
package procstat
import (
"bytes"
"fmt"
"io/ioutil"
"os/exec"
"strconv"
"time"
@ -24,6 +27,8 @@ type Procstat struct {
Prefix string
ProcessName string
User string
SystemdUnit string
CGroup string `toml:"cgroup"`
PidTag bool
pidFinder PIDFinder
@ -42,6 +47,10 @@ var sampleConfig = `
# pattern = "nginx"
## user as argument for pgrep (ie, pgrep -u <user>)
# user = "nginx"
## Systemd unit name
# systemd_unit = "nginx.service"
## CGroup name or path
# cgroup = "systemd/system.slice/nginx.service"
## override for process_name
## This is optional; default is sourced from /proc/<pid>/status
@ -275,6 +284,12 @@ func (p *Procstat) findPids() ([]PID, map[string]string, error) {
} else if p.User != "" {
pids, err = f.Uid(p.User)
tags = map[string]string{"user": p.User}
} else if p.SystemdUnit != "" {
pids, err = p.systemdUnitPIDs()
tags = map[string]string{"systemd_unit": p.SystemdUnit}
} else if p.CGroup != "" {
pids, err = p.cgroupPIDs()
tags = map[string]string{"cgroup": p.CGroup}
} else {
err = fmt.Errorf("Either exe, pid_file, user, or pattern has to be specified")
}
@ -282,6 +297,59 @@ func (p *Procstat) findPids() ([]PID, map[string]string, error) {
return pids, tags, err
}
func (p *Procstat) systemdUnitPIDs() ([]PID, error) {
var pids []PID
cmd := exec.Command("systemctl", "show", p.SystemdUnit)
out, err := cmd.Output()
if err != nil {
return nil, err
}
for _, line := range bytes.Split(out, []byte{'\n'}) {
kv := bytes.SplitN(line, []byte{'='}, 2)
if len(kv) != 2 {
continue
}
if !bytes.Equal(kv[0], []byte("MainPID")) {
continue
}
if len(kv[1]) == 0 {
return nil, nil
}
pid, err := strconv.Atoi(string(kv[1]))
if err != nil {
return nil, fmt.Errorf("invalid pid '%s'", kv[1])
}
pids = append(pids, PID(pid))
}
return pids, nil
}
func (p *Procstat) cgroupPIDs() ([]PID, error) {
var pids []PID
procsPath := p.CGroup
if procsPath[0] != '/' {
procsPath = "/sys/fs/cgroup/" + procsPath
}
procsPath = procsPath + "/cgroup.procs"
out, err := ioutil.ReadFile(procsPath)
if err != nil {
return nil, err
}
for _, pidBS := range bytes.Split(out, []byte{'\n'}) {
if len(pidBS) == 0 {
continue
}
pid, err := strconv.Atoi(string(pidBS))
if err != nil {
return nil, fmt.Errorf("invalid pid '%s'", pidBS)
}
pids = append(pids, PID(pid))
}
return pids, nil
}
func init() {
inputs.Add("procstat", func() telegraf.Input {
return &Procstat{}