[receiver/hostmetricsreceiver] Add process.parent_pid attribute to pr…

…ocess metrics (open-telemetry#12637)

receiver/hostmetricsreceiver/internal/scraper/processscraper/documentation.md

@@ -33,6 +33,7 @@ metrics:
 | process.executable.name | The name of the process executable. On Linux based systems, can be set to the Name in proc/[pid]/status. On Windows, can be set to the base name of GetProcessImageFileNameW. | String |
 | process.executable.path | The full path to the process executable. On Linux based systems, can be set to the target of proc/[pid]/exe. On Windows, can be set to the result of GetProcessImageFileNameW. | String |
 | process.owner | The username of the user that owns the process. | String |
+| process.parent_pid | Parent Process identifier (PPID). | Int |
 | process.pid | Process identifier (PID). | Int |
 
 ## Metric attributes

receiver/hostmetricsreceiver/internal/scraper/processscraper/metadata.yaml

@@ -6,6 +6,9 @@ resource_attributes:
  process.pid:
  description: Process identifier (PID).
  type: int
+ process.parent_pid:
+ description: Parent Process identifier (PPID).
+ type: int
  process.executable.name:
  description: >-
  The name of the process executable. On Linux based systems, can be set to the

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

@@ -29,6 +29,7 @@ import (
 
 type processMetadata struct {
  pid int32
+ parentPid int32
  executable *executableMetadata
  command *commandMetadata
  username string
@@ -50,6 +51,7 @@ func (m *processMetadata) resourceOptions() []metadata.ResourceMetricsOption {
  opts := make([]metadata.ResourceMetricsOption, 0, 6)
  opts = append(opts,
  metadata.WithProcessPid(int64(m.pid)),
+ metadata.WithProcessParentPid(int64(m.parentPid)),
  metadata.WithProcessExecutableName(m.executable.name),
  metadata.WithProcessExecutablePath(m.executable.path),
  )
@@ -88,6 +90,7 @@ type processHandle interface {
  MemoryInfo() (*process.MemoryInfoStat, error)
  IOCounters() (*process.IOCountersStat, error)
  CreateTime() (int64, error)
+ Parent() (*process.Process, error)
 }
 
 type gopsProcessHandles struct {
@@ -114,3 +117,23 @@ func getProcessHandlesInternal() (processHandles, error) {
 
  return &gopsProcessHandles{handles: processes}, nil
 }
+
+func parentPid(handle processHandle, pid int32) (int32, error) {
+ // special case for pid 0
+ if pid == 0 {
+ return 0, nil
+ }
+ parent, err := handle.Parent()
+
+ if err != nil {
+ // return pid of -1 along with error for all other problems retrieving parent pid
+ return -1, err
+ }
+
+ // if a process does not have a parent return 0
+ if parent == nil {
+ return 0, nil
+ }
+
+ return parent.Pid, nil
+}

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

@@ -181,8 +181,14 @@ func (s *scraper) getProcessMetadata() ([]*processMetadata, error) {
  continue
  }
 
+ parentPid, err := parentPid(handle, pid)
+ if err != nil {
+ errs.AddPartial(0, fmt.Errorf("error reading parent pid for process %q (pid %v): %w", executable.name, pid, err))
+ }
+
  md := &processMetadata{
  pid: pid,
+ parentPid: parentPid,
  executable: executable,
  command: command,
  username: username,

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

@@ -133,6 +133,7 @@ func assertProcessResourceAttributesExist(t *testing.T, resourceMetrics pmetric.
  internal.AssertContainsAttribute(t, attr, conventions.AttributeProcessCommand)
  internal.AssertContainsAttribute(t, attr, conventions.AttributeProcessCommandLine)
  internal.AssertContainsAttribute(t, attr, conventions.AttributeProcessOwner)
+ internal.AssertContainsAttribute(t, attr, "process.parent_pid")
  }
 }
 
@@ -310,6 +311,11 @@ func (p *processHandleMock) CreateTime() (int64, error) {
  return args.Get(0).(int64), args.Error(1)
 }
 
+func (p *processHandleMock) Parent() (*process.Process, error) {
+ args := p.MethodCalled("Parent")
+ return args.Get(0).(*process.Process), args.Error(1)
+}
+
 func newDefaultHandleMock() *processHandleMock {
  handleMock := &processHandleMock{}
  handleMock.On("Username").Return("username", nil)
@@ -318,6 +324,7 @@ func newDefaultHandleMock() *processHandleMock {
  handleMock.On("Times").Return(&cpu.TimesStat{}, nil)
  handleMock.On("MemoryInfo").Return(&process.MemoryInfoStat{}, nil)
  handleMock.On("IOCounters").Return(&process.IOCountersStat{}, nil)
+ handleMock.On("Parent").Return(&process.Process{Pid: 2}, nil)
  return handleMock
 }
 
@@ -460,6 +467,7 @@ func TestScrapeMetrics_ProcessErrors(t *testing.T) {
  memoryInfoError error
  ioCountersError error
  createTimeError error
+ parentPidError error
  expectedError string
  }
 
@@ -505,6 +513,11 @@ func TestScrapeMetrics_ProcessErrors(t *testing.T) {
  ioCountersError: errors.New("err7"),
  expectedError: `error reading disk usage for process "test" (pid 1): err7`,
  },
+ {
+ name: "Parent PID Error",
+ parentPidError: errors.New("err8"),
+ expectedError: `error reading parent pid for process "test" (pid 1): err8`,
+ },
  {
  name: "Multiple Errors",
  cmdlineError: errors.New("err2"),
@@ -548,6 +561,7 @@ func TestScrapeMetrics_ProcessErrors(t *testing.T) {
  handleMock.On("MemoryInfo").Return(&process.MemoryInfoStat{}, test.memoryInfoError)
  handleMock.On("IOCounters").Return(&process.IOCountersStat{}, test.ioCountersError)
  handleMock.On("CreateTime").Return(int64(0), test.createTimeError)
+ handleMock.On("Parent").Return(&process.Process{Pid: 2}, test.parentPidError)
 
  scraper.getProcessHandles = func() (processHandles, error) {
  return &processHandlesMock{handles: []*processHandleMock{handleMock}}, nil

unreleased/hostmetrics-receiver-ppid-attribute.yaml

@@ -0,0 +1,15 @@
+# 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: hostmetricsreceiver
+
+# A brief description of the change
+note: Add new resource attribute `process.parent_pid`. The value of the attribute is the parent PID
+
+# One or more tracking issues related to the change
+issues: [12290]
+
+# (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.
+subtext: