Add option to run varnish under sudo (#3097)

This commit is contained in:
Benjamin Stromski 2017-08-09 13:38:54 -05:00 committed by Daniel Nelson
parent 6f0ff514c9
commit 83c9b8ad9c
3 changed files with 86 additions and 15 deletions

View File

@ -7,6 +7,9 @@ This plugin gathers stats from [Varnish HTTP Cache](https://varnish-cache.org/)
```toml ```toml
# A plugin to collect stats from Varnish HTTP Cache # A plugin to collect stats from Varnish HTTP Cache
[[inputs.varnish]] [[inputs.varnish]]
## If running as a restricted user you can prepend sudo for additional access:
#use_sudo = false
## The default location of the varnishstat binary can be overridden with: ## The default location of the varnishstat binary can be overridden with:
binary = "/usr/bin/varnishstat" binary = "/usr/bin/varnishstat"
@ -330,6 +333,63 @@ the following values:
- LCK - LCK
### Permissions:
It's important to note that this plugin references varnishstat, which may require additional permissions to execute successfully.
Depending on the user/group permissions of the telegraf user executing this plugin, you may need to alter the group membership, set facls, or use sudo.
**Group membership (Recommended)**:
```bash
$ groups telegraf
telegraf : telegraf
$ usermod -a -G varnish telegraf
$ groups telegraf
telegraf : telegraf varnish
```
**Extended filesystem ACL's**:
```bash
$ getfacl /var/lib/varnish/<hostname>/_.vsm
# file: var/lib/varnish/<hostname>/_.vsm
# owner: root
# group: root
user::rw-
group::r--
other::---
$ setfacl -m u:telegraf:r /var/lib/varnish/<hostname>/_.vsm
$ getfacl /var/lib/varnish/<hostname>/_.vsm
# file: var/lib/varnish/<hostname>/_.vsm
# owner: root
# group: root
user::rw-
user:telegraf:r--
group::r--
mask::r--
other::---
```
**Sudo privileges**:
```bash
# If you use this method, you will need the following in your telegraf config:
[[inputs.varnish]]
use_sudo = true
$ visudo
# Add the following line:
telegraf ALL=(ALL) NOPASSWD: /usr/bin/varnishstat
$ grep varnish /etc/sudoers
telegraf ALL = NOPASSWD: /usr/bin/varnishstat
```
Please use the solution you see as most appropriate.
### Example Output: ### Example Output:
``` ```

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@ -17,12 +17,13 @@ import (
"github.com/influxdata/telegraf/plugins/inputs" "github.com/influxdata/telegraf/plugins/inputs"
) )
type runner func(cmdName string) (*bytes.Buffer, error) type runner func(cmdName string, UseSudo bool) (*bytes.Buffer, error)
// Varnish is used to store configuration values // Varnish is used to store configuration values
type Varnish struct { type Varnish struct {
Stats []string Stats []string
Binary string Binary string
UseSudo bool
filter filter.Filter filter filter.Filter
run runner run runner
@ -32,6 +33,9 @@ var defaultStats = []string{"MAIN.cache_hit", "MAIN.cache_miss", "MAIN.uptime"}
var defaultBinary = "/usr/bin/varnishstat" var defaultBinary = "/usr/bin/varnishstat"
var sampleConfig = ` var sampleConfig = `
## If running as a restricted user you can prepend sudo for additional access:
#use_sudo = false
## The default location of the varnishstat binary can be overridden with: ## The default location of the varnishstat binary can be overridden with:
binary = "/usr/bin/varnishstat" binary = "/usr/bin/varnishstat"
@ -52,10 +56,16 @@ func (s *Varnish) SampleConfig() string {
} }
// Shell out to varnish_stat and return the output // Shell out to varnish_stat and return the output
func varnishRunner(cmdName string) (*bytes.Buffer, error) { func varnishRunner(cmdName string, UseSudo bool) (*bytes.Buffer, error) {
cmdArgs := []string{"-1"} cmdArgs := []string{"-1"}
cmd := exec.Command(cmdName, cmdArgs...) cmd := exec.Command(cmdName, cmdArgs...)
if UseSudo {
cmdArgs = append([]string{cmdName}, cmdArgs...)
cmdArgs = append([]string{"-n"}, cmdArgs...)
cmd = exec.Command("sudo", cmdArgs...)
}
var out bytes.Buffer var out bytes.Buffer
cmd.Stdout = &out cmd.Stdout = &out
err := internal.RunTimeout(cmd, time.Millisecond*200) err := internal.RunTimeout(cmd, time.Millisecond*200)
@ -89,7 +99,7 @@ func (s *Varnish) Gather(acc telegraf.Accumulator) error {
} }
} }
out, err := s.run(s.Binary) out, err := s.run(s.Binary, s.UseSudo)
if err != nil { if err != nil {
return fmt.Errorf("error gathering metrics: %s", err) return fmt.Errorf("error gathering metrics: %s", err)
} }
@ -145,9 +155,10 @@ func (s *Varnish) Gather(acc telegraf.Accumulator) error {
func init() { func init() {
inputs.Add("varnish", func() telegraf.Input { inputs.Add("varnish", func() telegraf.Input {
return &Varnish{ return &Varnish{
run: varnishRunner, run: varnishRunner,
Stats: defaultStats, Stats: defaultStats,
Binary: defaultBinary, Binary: defaultBinary,
UseSudo: false,
} }
}) })
} }

View File

@ -11,8 +11,8 @@ import (
"testing" "testing"
) )
func fakeVarnishStat(output string) func(string) (*bytes.Buffer, error) { func fakeVarnishStat(output string, useSudo bool) func(string, bool) (*bytes.Buffer, error) {
return func(string) (*bytes.Buffer, error) { return func(string, bool) (*bytes.Buffer, error) {
return bytes.NewBuffer([]byte(output)), nil return bytes.NewBuffer([]byte(output)), nil
} }
} }
@ -20,7 +20,7 @@ func fakeVarnishStat(output string) func(string) (*bytes.Buffer, error) {
func TestGather(t *testing.T) { func TestGather(t *testing.T) {
acc := &testutil.Accumulator{} acc := &testutil.Accumulator{}
v := &Varnish{ v := &Varnish{
run: fakeVarnishStat(smOutput), run: fakeVarnishStat(smOutput, false),
Stats: []string{"*"}, Stats: []string{"*"},
} }
v.Gather(acc) v.Gather(acc)
@ -36,7 +36,7 @@ func TestGather(t *testing.T) {
func TestParseFullOutput(t *testing.T) { func TestParseFullOutput(t *testing.T) {
acc := &testutil.Accumulator{} acc := &testutil.Accumulator{}
v := &Varnish{ v := &Varnish{
run: fakeVarnishStat(fullOutput), run: fakeVarnishStat(fullOutput, true),
Stats: []string{"*"}, Stats: []string{"*"},
} }
err := v.Gather(acc) err := v.Gather(acc)
@ -51,7 +51,7 @@ func TestParseFullOutput(t *testing.T) {
func TestFilterSomeStats(t *testing.T) { func TestFilterSomeStats(t *testing.T) {
acc := &testutil.Accumulator{} acc := &testutil.Accumulator{}
v := &Varnish{ v := &Varnish{
run: fakeVarnishStat(fullOutput), run: fakeVarnishStat(fullOutput, false),
Stats: []string{"MGT.*", "VBE.*"}, Stats: []string{"MGT.*", "VBE.*"},
} }
err := v.Gather(acc) err := v.Gather(acc)
@ -74,7 +74,7 @@ func TestFieldConfig(t *testing.T) {
for fieldCfg, expected := range expect { for fieldCfg, expected := range expect {
acc := &testutil.Accumulator{} acc := &testutil.Accumulator{}
v := &Varnish{ v := &Varnish{
run: fakeVarnishStat(fullOutput), run: fakeVarnishStat(fullOutput, true),
Stats: strings.Split(fieldCfg, ","), Stats: strings.Split(fieldCfg, ","),
} }
err := v.Gather(acc) err := v.Gather(acc)