4 Commits

Author SHA1 Message Date
7bd5bef0cb fix broken error filtration 2023-06-28 23:43:20 -07:00
a82f845b84 add IsRunning helper 2023-06-20 23:49:23 -04:00
c9e7f79f8c add IsMasked utility 2023-06-20 23:40:22 -04:00
0075dc6b4d update to fix some tests, remove panics, and wrap errors 2023-06-17 23:18:28 -04:00
8 changed files with 258 additions and 211 deletions

View File

@@ -5,7 +5,6 @@ This library aims at providing idiomatic `systemctl` bindings for go developers,
This tool tries to take guesswork out of arbitrarily shelling out to `systemctl` by providing a structured, thoroughly-tested wrapper for the `systemctl` functions most-likely to be used in a system program.
If your system isn't running (or targeting another system running) `systemctl`, this library will be of little use to you.
In fact, if `systemctl` isn't found in the `PATH`, this library will panic.
## What is systemctl

View File

@@ -21,7 +21,6 @@ var (
// Masked units can only be unmasked, but something else was attempted
// Unmask the unit before enabling or disabling it
ErrMasked = errors.New("unit masked")
// If this error occurs, the library isn't entirely useful, as it causes a panic
// Make sure systemctl is in the PATH before calling again
ErrNotInstalled = errors.New("systemctl not in $PATH")
// A unit was expected to be running but was found inactive

View File

@@ -2,6 +2,7 @@ package systemctl
import (
"context"
"errors"
"fmt"
"reflect"
"runtime"
@@ -63,7 +64,7 @@ func TestErrorFuncs(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
err := f(ctx, tc.unit, tc.opts)
if err != tc.err {
if !errors.Is(err, tc.err) {
t.Errorf("error is %v, but should have been %v", err, tc.err)
}
})

2
go.mod
View File

@@ -1,3 +1,3 @@
module github.com/taigrr/systemctl
go 1.17
go 1.12

View File

@@ -2,7 +2,9 @@ package systemctl
import (
"context"
"errors"
"strconv"
"strings"
"time"
"github.com/taigrr/systemctl/properties"
@@ -52,3 +54,53 @@ func GetPID(ctx context.Context, unit string, opts Options) (int, error) {
}
return strconv.Atoi(value)
}
func GetMaskedUnits(ctx context.Context, opts Options) ([]string, error) {
args := []string{"list-unit-files", "--state=masked"}
if opts.UserMode {
args = append(args, "--user")
}
stdout, stderr, _, err := execute(ctx, args)
if err != nil {
return []string{}, errors.Join(err, filterErr(stderr))
}
lines := strings.Split(stdout, "\n")
units := []string{}
for _, line := range lines {
if !strings.Contains(line, "masked") {
continue
}
entry := strings.Split(line, " ")
if len(entry) < 3 {
continue
}
if entry[1] == "masked" {
unit := entry[0]
uName := strings.Split(unit, ".")
unit = uName[0]
units = append(units, unit)
}
}
return units, nil
}
// check if a service is masked
func IsMasked(ctx context.Context, unit string, opts Options) (bool, error) {
units, err := GetMaskedUnits(ctx, opts)
if err != nil {
return false, err
}
for _, u := range units {
if u == unit {
return true, nil
}
}
return false, nil
}
// check if a service is running
// https://unix.stackexchange.com/a/396633
func IsRunning(ctx context.Context, unit string, opts Options) (bool, error) {
status, err := Show(ctx, unit, properties.SubState, opts)
return status == "running", err
}

View File

@@ -2,6 +2,7 @@ package systemctl
import (
"context"
"errors"
"fmt"
"syscall"
"testing"
@@ -58,13 +59,13 @@ func TestGetStartTime(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
_, err := GetStartTime(ctx, tc.unit, tc.opts)
if err != tc.err {
if !errors.Is(err, tc.err) {
t.Errorf("error is %v, but should have been %v", err, tc.err)
}
})
}
// Prove start time changes after a restart
t.Run(fmt.Sprintf("prove start time changes"), func(t *testing.T) {
t.Run("prove start time changes", func(t *testing.T) {
if userString != "root" && userString != "system" {
t.Skip("skipping superuser test while running as user")
}
@@ -93,12 +94,13 @@ func TestGetStartTime(t *testing.T) {
}
func TestGetNumRestarts(t *testing.T) {
testCases := []struct {
type testCase struct {
unit string
err error
opts Options
runAsUser bool
}{
}
testCases := []testCase{
// Run these tests only as a user
// try nonexistant unit in user mode as user
@@ -118,6 +120,7 @@ func TestGetNumRestarts(t *testing.T) {
{"nginx", nil, Options{UserMode: false}, false},
}
for _, tc := range testCases {
func(tc testCase) {
t.Run(fmt.Sprintf("%s as %s", tc.unit, userString), func(t *testing.T) {
t.Parallel()
if (userString == "root" || userString == "system") && tc.runAsUser {
@@ -128,13 +131,14 @@ func TestGetNumRestarts(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
_, err := GetNumRestarts(ctx, tc.unit, tc.opts)
if err != tc.err {
if !errors.Is(err, tc.err) {
t.Errorf("error is %v, but should have been %v", err, tc.err)
}
})
}(tc)
}
// Prove restart count increases by one after a restart
t.Run(fmt.Sprintf("prove restart count increases by one after a restart"), func(t *testing.T) {
t.Run("prove restart count increases by one after a restart", func(t *testing.T) {
if testing.Short() {
t.Skip("skipping in short mode")
}
@@ -154,9 +158,9 @@ func TestGetNumRestarts(t *testing.T) {
}
syscall.Kill(pid, syscall.SIGKILL)
for {
running, err := IsActive(ctx, "nginx", Options{UserMode: false})
if err != nil {
t.Errorf("error asserting nginx is up: %v", err)
running, errIsActive := IsActive(ctx, "nginx", Options{UserMode: false})
if errIsActive != nil {
t.Errorf("error asserting nginx is up: %v", errIsActive)
break
} else if running {
break
@@ -173,12 +177,13 @@ func TestGetNumRestarts(t *testing.T) {
}
func TestGetMemoryUsage(t *testing.T) {
testCases := []struct {
type testCase struct {
unit string
err error
opts Options
runAsUser bool
}{
}
testCases := []testCase{
// Run these tests only as a user
// try nonexistant unit in user mode as user
@@ -198,6 +203,7 @@ func TestGetMemoryUsage(t *testing.T) {
{"nginx", nil, Options{UserMode: false}, false},
}
for _, tc := range testCases {
func(tc testCase) {
t.Run(fmt.Sprintf("%s as %s", tc.unit, userString), func(t *testing.T) {
t.Parallel()
if (userString == "root" || userString == "system") && tc.runAsUser {
@@ -208,13 +214,14 @@ func TestGetMemoryUsage(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
_, err := GetMemoryUsage(ctx, tc.unit, tc.opts)
if err != tc.err {
if !errors.Is(err, tc.err) {
t.Errorf("error is %v, but should have been %v", err, tc.err)
}
})
}(tc)
}
// Prove memory usage values change across services
t.Run(fmt.Sprintf("prove memory usage values change across services"), func(t *testing.T) {
t.Run("prove memory usage values change across services", func(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
bytes, err := GetMemoryUsage(ctx, "nginx", Options{UserMode: false})
@@ -232,12 +239,14 @@ func TestGetMemoryUsage(t *testing.T) {
}
func TestGetPID(t *testing.T) {
testCases := []struct {
type testCase struct {
unit string
err error
opts Options
runAsUser bool
}{
}
testCases := []testCase{
// Run these tests only as a user
// try nonexistant unit in user mode as user
@@ -257,6 +266,7 @@ func TestGetPID(t *testing.T) {
{"nginx", nil, Options{UserMode: false}, false},
}
for _, tc := range testCases {
func(tc testCase) {
t.Run(fmt.Sprintf("%s as %s", tc.unit, userString), func(t *testing.T) {
t.Parallel()
if (userString == "root" || userString == "system") && tc.runAsUser {
@@ -267,12 +277,13 @@ func TestGetPID(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
_, err := GetPID(ctx, tc.unit, tc.opts)
if err != tc.err {
if !errors.Is(err, tc.err) {
t.Errorf("error is %v, but should have been %v", err, tc.err)
}
})
}(tc)
}
t.Run(fmt.Sprintf("prove pid changes"), func(t *testing.T) {
t.Run("prove pid changes", func(t *testing.T) {
if testing.Short() {
t.Skip("skipping in short mode")
}

View File

@@ -2,6 +2,7 @@ package systemctl
import (
"context"
"errors"
"fmt"
"os"
"os/user"
@@ -41,7 +42,6 @@ func TestMain(m *testing.M) {
func TestDaemonReload(t *testing.T) {
testCases := []struct {
unit string
err error
opts Options
runAsUser bool
@@ -49,22 +49,26 @@ func TestDaemonReload(t *testing.T) {
/* Run these tests only as a user */
// fail to reload system daemon as user
{"", ErrInsufficientPermissions, Options{UserMode: false}, true},
{ErrInsufficientPermissions, Options{UserMode: false}, true},
// reload user's scope daemon
{"", nil, Options{UserMode: true}, true},
{nil, Options{UserMode: true}, true},
/* End user tests*/
/* Run these tests only as a superuser */
// succeed to reload daemon
{"", nil, Options{UserMode: false}, false},
{nil, Options{UserMode: false}, false},
// fail to connect to user bus as system
{"", ErrBusFailure, Options{UserMode: true}, false},
{ErrBusFailure, Options{UserMode: true}, false},
/* End superuser tests*/
}
for _, tc := range testCases {
t.Run(fmt.Sprintf("%s as %s", tc.unit, userString), func(t *testing.T) {
mode := "user"
if tc.opts.UserMode == false {
mode = "system"
}
t.Run(fmt.Sprintf("DaemonReload as %s, %s mode", userString, mode), func(t *testing.T) {
if (userString == "root" || userString == "system") && tc.runAsUser {
t.Skip("skipping user test while running as superuser")
} else if (userString != "root" && userString != "system") && !tc.runAsUser {
@@ -73,7 +77,7 @@ func TestDaemonReload(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
err := DaemonReload(ctx, tc.opts)
if err != tc.err {
if !errors.Is(err, tc.err) {
t.Errorf("error is %v, but should have been %v", err, tc.err)
}
})
@@ -81,7 +85,6 @@ func TestDaemonReload(t *testing.T) {
}
func TestDisable(t *testing.T) {
t.Run(fmt.Sprintf(""), func(t *testing.T) {
if userString != "root" && userString != "system" {
t.Skip("skipping superuser test while running as user")
}
@@ -94,7 +97,7 @@ func TestDisable(t *testing.T) {
t.Errorf("Unable to mask %s", unit)
}
err = Disable(ctx, unit, Options{UserMode: false})
if err != ErrMasked {
if !errors.Is(err, ErrMasked) {
Unmask(ctx, unit, Options{UserMode: false})
t.Errorf("error is %v, but should have been %v", err, ErrMasked)
}
@@ -102,11 +105,9 @@ func TestDisable(t *testing.T) {
if err != nil {
t.Errorf("Unable to unmask %s", unit)
}
})
}
func TestReenable(t *testing.T) {
t.Run(fmt.Sprintf(""), func(t *testing.T) {
if userString != "root" && userString != "system" {
t.Skip("skipping superuser test while running as user")
}
@@ -119,7 +120,7 @@ func TestReenable(t *testing.T) {
t.Errorf("Unable to mask %s", unit)
}
err = Reenable(ctx, unit, Options{UserMode: false})
if err != ErrMasked {
if !errors.Is(err, ErrMasked) {
Unmask(ctx, unit, Options{UserMode: false})
t.Errorf("error is %v, but should have been %v", err, ErrMasked)
}
@@ -127,11 +128,9 @@ func TestReenable(t *testing.T) {
if err != nil {
t.Errorf("Unable to unmask %s", unit)
}
})
}
func TestEnable(t *testing.T) {
t.Run(fmt.Sprintf(""), func(t *testing.T) {
if userString != "root" && userString != "system" {
t.Skip("skipping superuser test while running as user")
}
@@ -144,7 +143,7 @@ func TestEnable(t *testing.T) {
t.Errorf("Unable to mask %s", unit)
}
err = Enable(ctx, unit, Options{UserMode: false})
if err != ErrMasked {
if !errors.Is(err, ErrMasked) {
Unmask(ctx, unit, Options{UserMode: false})
t.Errorf("error is %v, but should have been %v", err, ErrMasked)
}
@@ -152,7 +151,6 @@ func TestEnable(t *testing.T) {
if err != nil {
t.Errorf("Unable to unmask %s", unit)
}
})
}
func ExampleEnable() {
@@ -161,16 +159,16 @@ func ExampleEnable() {
defer cancel()
err := Enable(ctx, unit, Options{UserMode: true})
switch err {
case ErrMasked:
switch {
case errors.Is(err, ErrMasked):
fmt.Printf("%s is masked, unmask it before enabling\n", unit)
case ErrDoesNotExist:
case errors.Is(err, ErrDoesNotExist):
fmt.Printf("%s does not exist\n", unit)
case ErrInsufficientPermissions:
case errors.Is(err, ErrInsufficientPermissions):
fmt.Printf("permission to enable %s denied\n", unit)
case ErrBusFailure:
case errors.Is(err, ErrBusFailure):
fmt.Printf("Cannot communicate with the bus\n")
case nil:
case err == nil:
fmt.Printf("%s enabled successfully\n", unit)
default:
fmt.Printf("Error: %v", err)
@@ -179,7 +177,7 @@ func ExampleEnable() {
func TestIsActive(t *testing.T) {
unit := "nginx"
t.Run(fmt.Sprintf("check active"), func(t *testing.T) {
t.Run("check active", func(t *testing.T) {
if testing.Short() {
t.Skip("skipping in short mode")
}
@@ -195,10 +193,10 @@ func TestIsActive(t *testing.T) {
time.Sleep(time.Second)
isActive, err := IsActive(ctx, unit, Options{UserMode: false})
if !isActive {
t.Errorf("IsActive didn't return true for %s", unit)
t.Errorf("IsActive didn't return true for %s: %v", unit, err)
}
})
t.Run(fmt.Sprintf("check masked"), func(t *testing.T) {
t.Run("check masked", func(t *testing.T) {
if userString != "root" && userString != "system" {
t.Skip("skipping superuser test while running as user")
}
@@ -214,7 +212,7 @@ func TestIsActive(t *testing.T) {
}
Unmask(ctx, unit, Options{UserMode: false})
})
t.Run(fmt.Sprintf("check masked"), func(t *testing.T) {
t.Run("check masked", func(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
_, err := IsActive(ctx, "nonexistant", Options{UserMode: false})
@@ -231,7 +229,7 @@ func TestIsEnabled(t *testing.T) {
userMode = true
unit = "syncthing"
}
t.Run(fmt.Sprintf("check enabled"), func(t *testing.T) {
t.Run("check enabled", func(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
err := Enable(ctx, unit, Options{UserMode: userMode})
@@ -240,10 +238,10 @@ func TestIsEnabled(t *testing.T) {
}
isEnabled, err := IsEnabled(ctx, unit, Options{UserMode: userMode})
if !isEnabled {
t.Errorf("IsEnabled didn't return true for %s", unit)
t.Errorf("IsEnabled didn't return true for %s: %v", unit, err)
}
})
t.Run(fmt.Sprintf("check disabled"), func(t *testing.T) {
t.Run("check disabled", func(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
err := Disable(ctx, unit, Options{UserMode: userMode})
@@ -259,7 +257,7 @@ func TestIsEnabled(t *testing.T) {
}
Enable(ctx, unit, Options{UserMode: false})
})
t.Run(fmt.Sprintf("check masked"), func(t *testing.T) {
t.Run("check masked", func(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
err := Mask(ctx, unit, Options{UserMode: userMode})
@@ -320,13 +318,13 @@ func TestMask(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
err := Mask(ctx, tc.unit, tc.opts)
if err != tc.err {
if !errors.Is(err, tc.err) {
t.Errorf("error is %v, but should have been %v", err, tc.err)
}
Unmask(ctx, tc.unit, tc.opts)
})
}
t.Run(fmt.Sprintf("test double masking existing"), func(t *testing.T) {
t.Run("test double masking existing", func(t *testing.T) {
unit := "nginx"
userMode := false
if userString != "root" && userString != "system" {
@@ -346,17 +344,15 @@ func TestMask(t *testing.T) {
}
Unmask(ctx, unit, opts)
})
t.Run(fmt.Sprintf("test double masking nonexisting"), func(t *testing.T) {
t.Run("test double masking nonexisting", func(t *testing.T) {
unit := "nonexistant"
userMode := false
if userString != "root" && userString != "system" {
userMode = true
}
userMode := userString != "root" && userString != "system"
opts := Options{UserMode: userMode}
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
err := Mask(ctx, unit, opts)
if err != ErrDoesNotExist {
if !errors.Is(err, ErrDoesNotExist) {
t.Errorf("error on initial masking is %v, but should have been %v", err, ErrDoesNotExist)
}
err = Mask(ctx, unit, opts)
@@ -388,9 +384,9 @@ func TestRestart(t *testing.T) {
}
syscall.Kill(pid, syscall.SIGKILL)
for {
running, err := IsActive(ctx, unit, opts)
if err != nil {
t.Errorf("error asserting %s is up: %v", unit, err)
running, errIsActive := IsActive(ctx, unit, opts)
if errIsActive != nil {
t.Errorf("error asserting %s is up: %v", unit, errIsActive)
break
} else if running {
break
@@ -415,6 +411,7 @@ func TestShow(t *testing.T) {
UserMode: false,
}
for _, x := range properties.Properties {
func(x properties.Property) {
t.Run(fmt.Sprintf("show property %s", string(x)), func(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
@@ -424,6 +421,7 @@ func TestShow(t *testing.T) {
t.Errorf("error is %v, but should have been %v", err, nil)
}
})
}(x)
}
}
@@ -551,13 +549,13 @@ func TestUnmask(t *testing.T) {
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
err := Mask(ctx, tc.unit, tc.opts)
if err != tc.err {
if !errors.Is(err, tc.err) {
t.Errorf("error is %v, but should have been %v", err, tc.err)
}
Unmask(ctx, tc.unit, tc.opts)
})
}
t.Run(fmt.Sprintf("test double unmasking existing"), func(t *testing.T) {
t.Run("test double unmasking existing", func(t *testing.T) {
unit := "nginx"
userMode := false
if userString != "root" && userString != "system" {
@@ -577,12 +575,10 @@ func TestUnmask(t *testing.T) {
}
Unmask(ctx, unit, opts)
})
t.Run(fmt.Sprintf("test double unmasking nonexisting"), func(t *testing.T) {
t.Run("test double unmasking nonexisting", func(t *testing.T) {
unit := "nonexistant"
userMode := false
if userString != "root" && userString != "system" {
userMode = true
}
userMode := userString != "root" && userString != "system"
opts := Options{UserMode: userMode}
ctx, cancel := context.WithTimeout(context.Background(), 1*time.Second)
defer cancel()
@@ -592,7 +588,7 @@ func TestUnmask(t *testing.T) {
t.Errorf("error on initial unmasking is %v, but should have been %v", err, nil)
}
err = Unmask(ctx, unit, opts)
if err != ErrDoesNotExist {
if !errors.Is(err, ErrDoesNotExist) {
t.Errorf("error on second unmasking is %v, but should have been %v", err, ErrDoesNotExist)
}
})

61
util.go
View File

@@ -3,10 +3,10 @@ package systemctl
import (
"bytes"
"context"
"errors"
"fmt"
"log"
"os/exec"
"regexp"
"strings"
)
var systemctl string
@@ -14,12 +14,7 @@ var systemctl string
const killed = 130
func init() {
path, err := exec.LookPath("systemctl")
if err != nil {
log.Printf("%v", ErrNotInstalled)
systemctl = ""
return
}
path, _ := exec.LookPath("systemctl")
systemctl = path
}
@@ -34,7 +29,7 @@ func execute(ctx context.Context, args []string) (string, string, int, error) {
)
if systemctl == "" {
panic(ErrNotInstalled)
return "", "", 1, ErrNotInstalled
}
cmd := exec.CommandContext(ctx, systemctl, args...)
cmd.Stdout = &stdout
@@ -56,32 +51,26 @@ func execute(ctx context.Context, args []string) (string, string, int, error) {
}
func filterErr(stderr string) error {
if matched, _ := regexp.MatchString(`does not exist`, stderr); matched {
return ErrDoesNotExist
}
if matched, _ := regexp.MatchString(`not found.`, stderr); matched {
return ErrDoesNotExist
}
if matched, _ := regexp.MatchString(`not loaded.`, stderr); matched {
return ErrUnitNotLoaded
}
if matched, _ := regexp.MatchString(`No such file or directory`, stderr); matched {
return ErrDoesNotExist
}
if matched, _ := regexp.MatchString(`Interactive authentication required`, stderr); matched {
return ErrInsufficientPermissions
}
if matched, _ := regexp.MatchString(`Access denied`, stderr); matched {
return ErrInsufficientPermissions
}
if matched, _ := regexp.MatchString(`DBUS_SESSION_BUS_ADDRESS`, stderr); matched {
return ErrBusFailure
}
if matched, _ := regexp.MatchString(`is masked`, stderr); matched {
return ErrMasked
}
if matched, _ := regexp.MatchString(`Failed`, stderr); matched {
return ErrUnspecified
}
switch {
case strings.Contains(stderr, `does not exist`):
return errors.Join(ErrDoesNotExist, fmt.Errorf("stderr: %s", stderr))
case strings.Contains(stderr, `not found.`):
return errors.Join(ErrDoesNotExist, fmt.Errorf("stderr: %s", stderr))
case strings.Contains(stderr, `not loaded.`):
return errors.Join(ErrUnitNotLoaded, fmt.Errorf("stderr: %s", stderr))
case strings.Contains(stderr, `No such file or directory`):
return errors.Join(ErrDoesNotExist, fmt.Errorf("stderr: %s", stderr))
case strings.Contains(stderr, `Interactive authentication required`):
return errors.Join(ErrInsufficientPermissions, fmt.Errorf("stderr: %s", stderr))
case strings.Contains(stderr, `Access denied`):
return errors.Join(ErrInsufficientPermissions, fmt.Errorf("stderr: %s", stderr))
case strings.Contains(stderr, `DBUS_SESSION_BUS_ADDRESS`):
return errors.Join(ErrBusFailure, fmt.Errorf("stderr: %s", stderr))
case strings.Contains(stderr, `is masked`):
return errors.Join(ErrMasked, fmt.Errorf("stderr: %s", stderr))
case strings.Contains(stderr, `Failed`):
return errors.Join(ErrUnspecified, fmt.Errorf("stderr: %s", stderr))
default:
return nil
}
}