[receiver/hostmetrics/scrapers/process]: add configuration option to …

…mute `error reading username for process` (open-telemetry#28661)

**Description:**

add configuration option `mute_process_user_error`) to mute `error
reading username for process`

**Link to tracking Issue:**

* open-telemetry#14311
* open-telemetry#17187

Signed-off-by: Dominik Rosiek <drosiek@sumologic.com>

.chloggen/drosiek-mute-process-user-error.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: receiver/hostmetrics/scrapers/process
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: add configuration option to mute `error reading username for process`
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [14311, 17187]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

receiver/hostmetricsreceiver/README.md

@@ -118,6 +118,7 @@ process:
   mute_process_name_error: <true|false>
   mute_process_exe_error: <true|false>
   mute_process_io_error: <true|false>
+  mute_process_user_error: <true|false>
   scrape_process_delay: <time>
 ```
 

receiver/hostmetricsreceiver/internal/scraper/processscraper/config.go

@@ -35,6 +35,10 @@ type Config struct {
 	// the collector does not have permission to read it's executable path (Linux)
 	MuteProcessExeError bool `mapstructure:"mute_process_exe_error,omitempty"`
 
+	// MuteProcessUserError is a flag that will mute the error encountered when trying to read uid which
+	// doesn't exist on the system, eg. is owned by user existing in container only
+	MuteProcessUserError bool `mapstructure:"mute_process_user_error,omitempty"`
+
 	// ScrapeProcessDelay is used to indicate the minimum amount of time a process must be running
 	// before metrics are scraped for it.  The default value is 0 seconds (0s)
 	ScrapeProcessDelay time.Duration `mapstructure:"scrape_process_delay"`

receiver/hostmetricsreceiver/internal/scraper/processscraper/process_scraper.go

@@ -219,7 +219,9 @@ func (s *scraper) getProcessMetadata() ([]*processMetadata, error) {
 
 		username, err := handle.UsernameWithContext(ctx)
 		if err != nil {
-			errs.AddPartial(0, fmt.Errorf("error reading username for process %q (pid %v): %w", executable.name, pid, err))
+			if !s.config.MuteProcessUserError {
+				errs.AddPartial(0, fmt.Errorf("error reading username for process %q (pid %v): %w", executable.name, pid, err))
+			}
 		}
 
 		createTime, err := s.getProcessCreateTime(handle, ctx)

receiver/hostmetricsreceiver/internal/scraper/processscraper/process_scraper_test.go

@@ -938,8 +938,11 @@ func TestScrapeMetrics_MuteErrorFlags(t *testing.T) {
 		muteProcessNameError bool
 		muteProcessExeError  bool
 		muteProcessIOError   bool
+		muteProcessUserError bool
+		skipProcessNameError bool
 		omitConfigField      bool
 		expectedError        string
+		expectedCount        int
 	}
 
 	testCases := []testCase{
@@ -948,6 +951,7 @@ func TestScrapeMetrics_MuteErrorFlags(t *testing.T) {
 			muteProcessNameError: true,
 			muteProcessExeError:  true,
 			muteProcessIOError:   true,
+			muteProcessUserError: true,
 		},
 		{
 			name:                 "Process Name Error Muted And Process Exe Error Enabled And Process IO Error Muted",
@@ -994,6 +998,23 @@ func TestScrapeMetrics_MuteErrorFlags(t *testing.T) {
 					fmt.Sprintf("error reading process name for pid 1: %v", processNameError)
 			}(),
 		},
+		{
+			name:                 "Process User Error Muted",
+			muteProcessUserError: true,
+			skipProcessNameError: true,
+			muteProcessExeError:  true,
+			muteProcessNameError: true,
+			expectedCount:        4,
+		},
+		{
+			name:                 "Process User Error Unmuted",
+			muteProcessUserError: false,
+			skipProcessNameError: true,
+			muteProcessExeError:  true,
+			muteProcessNameError: true,
+			expectedError:        fmt.Sprintf("error reading username for process \"processname\" (pid 1): %v", processNameError),
+			expectedCount:        4,
+		},
 	}
 
 	for _, test := range testCases {
@@ -1003,14 +1024,26 @@ func TestScrapeMetrics_MuteErrorFlags(t *testing.T) {
 				config.MuteProcessNameError = test.muteProcessNameError
 				config.MuteProcessExeError = test.muteProcessExeError
 				config.MuteProcessIOError = test.muteProcessIOError
+				config.MuteProcessUserError = test.muteProcessUserError
 			}
 			scraper, err := newProcessScraper(receivertest.NewNopCreateSettings(), config)
 			require.NoError(t, err, "Failed to create process scraper: %v", err)
 			err = scraper.start(context.Background(), componenttest.NewNopHost())
 			require.NoError(t, err, "Failed to initialize process scraper: %v", err)
 
-			handleMock := &processHandleMock{}
-			handleMock.On("NameWithContext", mock.Anything).Return("test", processNameError)
+			handleMock := newDefaultHandleMock()
+			if !test.skipProcessNameError {
+				handleMock.On("NameWithContext", mock.Anything).Return("test", processNameError)
+			} else {
+				for _, c := range handleMock.ExpectedCalls {
+					if c.Method == "UsernameWithContext" {
+						c.ReturnArguments = []interface{}{"processname", processNameError}
+						break
+					}
+				}
+				handleMock.On("NameWithContext", mock.Anything).Return("processname", nil)
+				handleMock.On("CreateTimeWithContext", mock.Anything).Return(time.Now().UnixMilli(), nil)
+			}
 			handleMock.On("ExeWithContext", mock.Anything).Return("test", processNameError)
 			handleMock.On("CmdlineWithContext", mock.Anything).Return("test", processNameError)
 
@@ -1023,9 +1056,9 @@ func TestScrapeMetrics_MuteErrorFlags(t *testing.T) {
 			}
 			md, err := scraper.scrape(context.Background())
 
-			assert.Zero(t, md.MetricCount())
+			assert.Equal(t, test.expectedCount, md.MetricCount())
 
-			if config.MuteProcessNameError && config.MuteProcessExeError {
+			if config.MuteProcessNameError && config.MuteProcessExeError && config.MuteProcessUserError {
 				assert.Nil(t, err)
 			} else {
 				assert.EqualError(t, err, test.expectedError)