From b991aab75d815f1337ed56be7d9eb0e39a863c44 Mon Sep 17 00:00:00 2001
From: Andreas Fuchs <asf@boinkor.net>
Date: Wed, 17 Feb 2021 15:50:25 -0500
Subject: [PATCH] plugins/filestat: Skip missing files (#7316)

---
 plugins/inputs/filestat/filestat.go      | 24 +++++++++++++++++++++---
 plugins/inputs/filestat/filestat_test.go | 17 +++++++++++++++++
 2 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/plugins/inputs/filestat/filestat.go b/plugins/inputs/filestat/filestat.go
index bf8ea6c16..9450f9a41 100644
--- a/plugins/inputs/filestat/filestat.go
+++ b/plugins/inputs/filestat/filestat.go
@@ -35,11 +35,18 @@ type FileStat struct {
 
 	// maps full file paths to globmatch obj
 	globs map[string]*globpath.GlobPath
+
+	// files that were missing - we only log the first time it's not found.
+	missingFiles map[string]bool
+	// files that had an error in Stat - we only log the first error.
+	filesWithErrors map[string]bool
 }
 
 func NewFileStat() *FileStat {
 	return &FileStat{
-		globs: make(map[string]*globpath.GlobPath),
+		globs:           make(map[string]*globpath.GlobPath),
+		missingFiles:    make(map[string]bool),
+		filesWithErrors: make(map[string]bool),
 	}
 }
 
@@ -85,12 +92,23 @@ func (f *FileStat) Gather(acc telegraf.Accumulator) error {
 			fileInfo, err := os.Stat(fileName)
 			if os.IsNotExist(err) {
 				fields["exists"] = int64(0)
+				acc.AddFields("filestat", fields, tags)
+				if !f.missingFiles[fileName] {
+					f.Log.Warnf("File %q not found", fileName)
+					f.missingFiles[fileName] = true
+				}
+				continue
 			}
+			f.missingFiles[fileName] = false
 
 			if fileInfo == nil {
-				f.Log.Errorf("Unable to get info for file %q, possible permissions issue",
-					fileName)
+				if !f.filesWithErrors[fileName] {
+					f.filesWithErrors[fileName] = true
+					f.Log.Errorf("Unable to get info for file %q: %v",
+						fileName, err)
+				}
 			} else {
+				f.filesWithErrors[fileName] = false
 				fields["size_bytes"] = fileInfo.Size()
 				fields["modification_time"] = fileInfo.ModTime().UnixNano()
 			}
diff --git a/plugins/inputs/filestat/filestat_test.go b/plugins/inputs/filestat/filestat_test.go
index 79a111ffb..f0b843dcb 100644
--- a/plugins/inputs/filestat/filestat_test.go
+++ b/plugins/inputs/filestat/filestat_test.go
@@ -83,6 +83,23 @@ func TestGatherExplicitFiles(t *testing.T) {
 	require.True(t, acc.HasPoint("filestat", tags3, "exists", int64(0)))
 }
 
+func TestNonExistentFile(t *testing.T) {
+	fs := NewFileStat()
+	fs.Log = testutil.Logger{}
+	fs.Md5 = true
+	fs.Files = []string{
+		"/non/existant/file",
+	}
+	acc := testutil.Accumulator{}
+	require.NoError(t, acc.GatherError(fs.Gather))
+
+	acc.AssertContainsFields(t, "filestat", map[string]interface{}{"exists": int64(0)})
+	assert.False(t, acc.HasField("filestat", "error"))
+	assert.False(t, acc.HasField("filestat", "md5_sum"))
+	assert.False(t, acc.HasField("filestat", "size_bytes"))
+	assert.False(t, acc.HasField("filestat", "modification_time"))
+}
+
 func TestGatherGlob(t *testing.T) {
 	fs := NewFileStat()
 	fs.Log = testutil.Logger{}