[receiver/hostmetrics] Make HOST_PROC_MOUNTINFO part of envMap (#35504)

**Description:** 
Make HOST_PROC_MOUNTINFO part of envMap instead of environment variable

.chloggen/use_HOST_PROC_MOUNTINFO.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: hostmetricsreceiver
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Use HOST_PROC_MOUNTINFO as part of configuration instead of environment variable
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [35504]
+
+# (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: []

receiver/hostmetricsreceiver/hostmetrics_linux.go

@@ -14,12 +14,13 @@ import (
 )
 
 var gopsutilEnvVars = map[common.EnvKeyType]string{
-	common.HostProcEnvKey: "/proc",
-	common.HostSysEnvKey:  "/sys",
-	common.HostEtcEnvKey:  "/etc",
-	common.HostVarEnvKey:  "/var",
-	common.HostRunEnvKey:  "/run",
-	common.HostDevEnvKey:  "/dev",
+	common.HostProcEnvKey:    "/proc",
+	common.HostSysEnvKey:     "/sys",
+	common.HostEtcEnvKey:     "/etc",
+	common.HostVarEnvKey:     "/var",
+	common.HostRunEnvKey:     "/run",
+	common.HostDevEnvKey:     "/dev",
+	common.HostProcMountinfo: "",
 }
 
 // This exists to validate that different instances of the hostmetricsreceiver do not

receiver/hostmetricsreceiver/hostmetrics_linux_test.go

@@ -50,11 +50,12 @@ func TestLoadConfigRootPath(t *testing.T) {
 	cpuScraperCfg := (&cpuscraper.Factory{}).CreateDefaultConfig()
 	cpuScraperCfg.SetRootPath("testdata")
 	cpuScraperCfg.SetEnvMap(common.EnvMap{
-		common.HostDevEnvKey: "testdata/dev",
-		common.HostEtcEnvKey: "testdata/etc",
-		common.HostRunEnvKey: "testdata/run",
-		common.HostSysEnvKey: "testdata/sys",
-		common.HostVarEnvKey: "testdata/var",
+		common.HostDevEnvKey:     "testdata/dev",
+		common.HostEtcEnvKey:     "testdata/etc",
+		common.HostProcMountinfo: "testdata",
+		common.HostRunEnvKey:     "testdata/run",
+		common.HostSysEnvKey:     "testdata/sys",
+		common.HostVarEnvKey:     "testdata/var",
 	})
 	expectedConfig.Scrapers = map[string]internal.Config{cpuscraper.TypeStr: cpuScraperCfg}
 

receiver/hostmetricsreceiver/internal/scraper/filesystemscraper/filesystem_scraper.go

@@ -6,7 +6,6 @@ package filesystemscraper // import "github.com/open-telemetry/opentelemetry-col
 import (
 	"context"
 	"fmt"
-	"os"
 	"path/filepath"
 	"strings"
 	"time"
@@ -111,7 +110,7 @@ func (s *scraper) scrape(ctx context.Context) (pmetric.Metrics, error) {
 		if !s.fsFilter.includePartition(partition) {
 			continue
 		}
-		translatedMountpoint := translateMountpoint(s.config.RootPath, partition.Mountpoint)
+		translatedMountpoint := translateMountpoint(ctx, s.config.RootPath, partition.Mountpoint)
 		usage, usageErr := s.usage(ctx, translatedMountpoint)
 		if usageErr != nil {
 			errors.AddPartial(0, fmt.Errorf("failed to read usage at %s: %w", translatedMountpoint, usageErr))
@@ -178,9 +177,12 @@ func (f *fsFilter) includeMountPoint(mountPoint string) bool {
 }
 
 // translateMountsRootPath translates a mountpoint from the host perspective to the chrooted perspective.
-func translateMountpoint(rootPath, mountpoint string) string {
-	if mountInfo := os.Getenv("HOST_PROC_MOUNTINFO"); mountInfo != "" {
-		return mountpoint
+func translateMountpoint(ctx context.Context, rootPath string, mountpoint string) string {
+	if env, ok := ctx.Value(common.EnvKey).(common.EnvMap); ok {
+		mountInfo := env[common.EnvKeyType("HOST_PROC_MOUNTINFO")]
+		if mountInfo != "" {
+			return mountpoint
+		}
 	}
 	return filepath.Join(rootPath, mountpoint)
 }

receiver/hostmetricsreceiver/internal/scraper/filesystemscraper/filesystem_scraper_test.go

@@ -11,6 +11,7 @@ import (
 	"runtime"
 	"testing"
 
+	"github.com/shirou/gopsutil/v4/common"
 	"github.com/shirou/gopsutil/v4/disk"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -30,7 +31,7 @@ func TestScrape(t *testing.T) {
 		name                     string
 		config                   Config
 		rootPath                 string
-		osEnv                    map[string]string
+		osEnv                    map[common.EnvKeyType]string
 		bootTimeFunc             func(context.Context) (uint64, error)
 		partitionsFunc           func(context.Context, bool) ([]disk.PartitionStat, error)
 		usageFunc                func(context.Context, string) (*disk.UsageStat, error)
@@ -198,8 +199,8 @@ func TestScrape(t *testing.T) {
 		},
 		{
 			name: "RootPath at /hostfs but HOST_PROC_MOUNTINFO is set",
-			osEnv: map[string]string{
-				"HOST_PROC_MOUNTINFO": "/proc/1/self",
+			osEnv: map[common.EnvKeyType]string{
+				common.HostProcMountinfo: "/proc/1/self",
 			},
 			config: Config{
 				MetricsBuilderConfig: metadata.DefaultMetricsBuilderConfig(),
@@ -387,9 +388,11 @@ func TestScrape(t *testing.T) {
 	for _, test := range testCases {
 		test := test
 		t.Run(test.name, func(t *testing.T) {
+			envMap := common.EnvMap{}
 			for k, v := range test.osEnv {
-				t.Setenv(k, v)
+				envMap[k] = v
 			}
+			test.config.EnvMap = envMap
 			test.config.SetRootPath(test.rootPath)
 			scraper, err := newFileSystemScraper(context.Background(), receivertest.NewNopSettings(), &test.config)
 			if test.newErrRegex != "" {

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

@@ -11,6 +11,7 @@ import (
 	"testing"
 	"time"
 
+	"github.com/shirou/gopsutil/v4/common"
 	"github.com/shirou/gopsutil/v4/cpu"
 	"github.com/shirou/gopsutil/v4/process"
 	"github.com/stretchr/testify/assert"
@@ -88,7 +89,17 @@ func TestScrape(t *testing.T) {
 			if test.mutateMetricsConfig != nil {
 				test.mutateMetricsConfig(t, &metricsBuilderConfig.Metrics)
 			}
-			scraper, err := newProcessScraper(receivertest.NewNopSettings(), &Config{MetricsBuilderConfig: metricsBuilderConfig})
+			cfg := &Config{MetricsBuilderConfig: metricsBuilderConfig}
+			cfg.EnvMap = common.EnvMap{
+				common.HostProcEnvKey:    "/proc",
+				common.HostSysEnvKey:     "/sys",
+				common.HostEtcEnvKey:     "/etc",
+				common.HostVarEnvKey:     "/var",
+				common.HostRunEnvKey:     "/run",
+				common.HostDevEnvKey:     "/dev",
+				common.HostProcMountinfo: "",
+			}
+			scraper, err := newProcessScraper(receivertest.NewNopSettings(), cfg)
 			if test.mutateScraper != nil {
 				test.mutateScraper(scraper)
 			}