🐛 proc Make sure that invalid PIDs are ignored when stopping processes (#668)

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### Description

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Make sure that invalid PIDs are ignored when stopping processes

### Test Coverage

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Author: joshjennings98

changes/20250807104110.bugfix

@@ -0,0 +1 @@
+:bug: `proc` Make sure that invalid PIDs are ignored when stopping processes

utils/proc/find/find_linux.go

@@ -17,8 +17,9 @@ import (
 )
 
 const (
-	procFS       = "/proc"
-	procDataFile = "cmdline"
+	procFS        = "/proc"
+	procDataFile  = "cmdline"
+	invalidPIDErr = "could not parse PID from proc path"
 )
 
 func checkProcessMatch(ctx context.Context, fs filesystem.FS, re *regexp.Regexp, procEntry string) (ok bool, err error) {
@@ -51,7 +52,7 @@ func parseProcess(ctx context.Context, entry string) (p proc.IProcess, err error
 
 	pid, err := strconv.Atoi(strings.Trim(strings.TrimSuffix(strings.TrimPrefix(entry, procFS), fmt.Sprintf("%v", procDataFile)), "/"))
 	if err != nil {
-		err = commonerrors.WrapErrorf(commonerrors.ErrUnexpected, err, "could not parse PID from proc path '%v'", entry)
+		err = commonerrors.WrapErrorf(commonerrors.ErrUnexpected, err, "%v '%v'", invalidPIDErr, entry)
 		return
 	}
 
@@ -75,7 +76,7 @@ func FindProcessByRegexForFS(ctx context.Context, fs filesystem.FS, re *regexp.R
 		return
 	}
 
-	searchGlobTerm := fmt.Sprintf("%v/*/%v", procFS, procDataFile)
+	searchGlobTerm := fmt.Sprintf("%v/[0-9]*/%v", procFS, procDataFile)
 	procEntries, err := fs.Glob(searchGlobTerm)
 	if err != nil {
 		err = commonerrors.WrapErrorf(commonerrors.ErrUnexpected, err, "an error occurred when searching for processes using the following glob '%v'", searchGlobTerm)
@@ -90,6 +91,7 @@ func FindProcessByRegexForFS(ctx context.Context, fs filesystem.FS, re *regexp.R
 
 		p, err = parseProcess(ctx, entry)
 		if err != nil {
+			err = commonerrors.IgnoreCorrespondTo(err, invalidPIDErr)
 			return
 		}
 

utils/proc/find/find_linux_test.go

@@ -13,6 +13,7 @@ import (
 
 	"github.com/ARM-software/golang-utils/utils/commonerrors"
 	"github.com/ARM-software/golang-utils/utils/commonerrors/errortest"
+	"github.com/ARM-software/golang-utils/utils/filesystem"
 	"github.com/ARM-software/golang-utils/utils/logs"
 	"github.com/ARM-software/golang-utils/utils/logs/logstest"
 	"github.com/ARM-software/golang-utils/utils/subprocess"
@@ -87,4 +88,12 @@ func TestFind(t *testing.T) {
 		assert.Empty(t, processes)
 	})
 
+	t.Run("Exclude invalid", func(t *testing.T) {
+		ctx := context.Background()
+		allProcesses, err := filesystem.Glob(fmt.Sprintf("%v/[0-9]*/%v", procFS, procDataFile))
+		require.NoError(t, err)
+		processes, err := FindProcessByName(ctx, "") // empty name will return all processes that were valid according to the logic (e.g. no invalid names or empty cmdline files)
+		assert.NoError(t, err)
+		assert.LessOrEqual(t, len(processes), len(allProcesses))
+	})
 }