From c95c8a248459ebc7aa5d1c7708449f4848ebfc8b Mon Sep 17 00:00:00 2001
From: Sven Rebhan <srebhan@influxdata.com>
Date: Thu, 19 May 2022 18:07:35 +0200
Subject: [PATCH] fix: Improve slab testing without sudo.

---
 plugins/inputs/slab/slab.go      | 25 ++++++++-------
 plugins/inputs/slab/slab_test.go | 52 ++++----------------------------
 2 files changed, 18 insertions(+), 59 deletions(-)

diff --git a/plugins/inputs/slab/slab.go b/plugins/inputs/slab/slab.go
index a18513df98789..6ad0e52b9cee0 100644
--- a/plugins/inputs/slab/slab.go
+++ b/plugins/inputs/slab/slab.go
@@ -20,18 +20,11 @@ import (
 	"github.com/influxdata/telegraf/plugins/inputs"
 )
 
-func init() {
-	inputs.Add("slab", func() telegraf.Input {
-		return &SlabStats{
-			statFile: path.Join(getHostProc(), "/slabinfo"),
-		}
-	})
-}
-
 type SlabStats struct {
 	Log telegraf.Logger `toml:"-"`
 
 	statFile string
+	useSudo  bool
 }
 
 func (ss *SlabStats) Init() error {
@@ -91,16 +84,13 @@ func (ss *SlabStats) getSlabStats() (map[string]interface{}, error) {
 
 func (ss *SlabStats) runCmd(cmd string, args []string) ([]byte, error) {
 	execCmd := exec.Command(cmd, args...)
-	if os.Geteuid() != 0 {
+	if ss.useSudo {
 		execCmd = exec.Command("sudo", append([]string{"-n", cmd}, args...)...)
 	}
 
 	out, err := internal.StdOutputTimeout(execCmd, 5*time.Second)
 	if err != nil {
-		return nil, fmt.Errorf(
-			"failed to run command %s: %s - %s",
-			strings.Join(execCmd.Args, " "), err, string(out),
-		)
+		return nil, fmt.Errorf("failed to run command %s: %s - %v", execCmd.Args, err, out)
 	}
 
 	return out, nil
@@ -117,3 +107,12 @@ func getHostProc() string {
 func normalizeName(name string) string {
 	return strings.ReplaceAll(strings.ToLower(name), "-", "_") + "_size"
 }
+
+func init() {
+	inputs.Add("slab", func() telegraf.Input {
+		return &SlabStats{
+			statFile: path.Join(getHostProc(), "slabinfo"),
+			useSudo:  true,
+		}
+	})
+}
diff --git a/plugins/inputs/slab/slab_test.go b/plugins/inputs/slab/slab_test.go
index e5eda8f13666b..a4b26e6e63162 100644
--- a/plugins/inputs/slab/slab_test.go
+++ b/plugins/inputs/slab/slab_test.go
@@ -4,37 +4,22 @@
 package slab
 
 import (
-	"os"
+	"path"
 	"testing"
 
-	"github.com/influxdata/telegraf/testutil"
 	"github.com/stretchr/testify/require"
-)
-
-func makeFakeStatFile(content []byte) string {
-	tmpfile, err := os.CreateTemp("", "slab_test")
-	if err != nil {
-		panic(err)
-	}
 
-	if _, err := tmpfile.Write(content); err != nil {
-		panic(err)
-	}
-	if err := tmpfile.Close(); err != nil {
-		panic(err)
-	}
-
-	return tmpfile.Name()
-}
+	"github.com/influxdata/telegraf/testutil"
+)
 
 func TestSlab(t *testing.T) {
 	slabStats := SlabStats{
-		statFile: makeFakeStatFile([]byte(procSlabInfo)),
+		statFile: path.Join("testdata", "slabinfo"),
+		useSudo:  false,
 	}
 
 	var acc testutil.Accumulator
-	err := acc.GatherError(slabStats.Gather)
-	require.NoError(t, err)
+	require.NoError(t, slabStats.Gather(&acc))
 
 	fields := map[string]interface{}{
 		"ext4_allocation_context_size": int(16384),
@@ -62,28 +47,3 @@ func TestSlab(t *testing.T) {
 
 	acc.AssertContainsFields(t, "slab", fields)
 }
-
-var procSlabInfo = `slabinfo - version: 2.1
-# name            <active_objs> <num_objs> <objsize> <objperslab> <pagesperslab> : tunables <limit> <batchcount> <sharedfactor> : slabdata <active_slabs> <num_slabs> <sharedavail>
-ext4_inode_cache     480    480   1024   32    8 : tunables    0    0    0 : slabdata     15     15      0
-ext4_xattr             0      0     88   46    1 : tunables    0    0    0 : slabdata      0      0      0
-ext4_free_data         0      0     64   64    1 : tunables    0    0    0 : slabdata      0      0      0
-ext4_allocation_context    128    128    128   32    1 : tunables    0    0    0 : slabdata      4      4      0
-ext4_io_end           56     56     72   56    1 : tunables    0    0    0 : slabdata      1      1      0
-ext4_extent_status    204    204     40  102    1 : tunables    0    0    0 : slabdata      2      2      0
-kmalloc-8192         106    128   8192    4    8 : tunables    0    0    0 : slabdata     32     32      0
-kmalloc-4096         486    576   4096    8    8 : tunables    0    0    0 : slabdata     72     72      0
-kmalloc-2048        1338   1616   2048   16    8 : tunables    0    0    0 : slabdata    101    101      0
-kmalloc-1024      155845 234304   1024   32    8 : tunables    0    0    0 : slabdata   7329   7329      0
-kmalloc-512        18995  80928    512   32    4 : tunables    0    0    0 : slabdata   2529   2529      0
-kmalloc-256        16366  21184    256   32    2 : tunables    0    0    0 : slabdata    662    662      0
-kmalloc-192        18835  20916    192   21    1 : tunables    0    0    0 : slabdata    996    996      0
-kmalloc-128        23600  43648    128   32    1 : tunables    0    0    0 : slabdata   1364   1364      0
-kmalloc-96         95106 128940     96   42    1 : tunables    0    0    0 : slabdata   3070   3070      0
-kmalloc-64         82432 133376     64   64    1 : tunables    0    0    0 : slabdata   2084   2084      0
-kmalloc-32         78477 114304     32  128    1 : tunables    0    0    0 : slabdata    893    893      0
-kmalloc-16        885605 1062656     16  256    1 : tunables    0    0    0 : slabdata   4151   4151      0
-kmalloc-8          28672  28672      8  512    1 : tunables    0    0    0 : slabdata     56     56      0
-kmem_cache_node      576    576     64   64    1 : tunables    0    0    0 : slabdata      9      9      0
-kmem_cache           320    320    256   32    2 : tunables    0    0    0 : slabdata     10     10      0
-`