Use an absolute path when calling bsd kenv (#8113)

Co-authored-by: Robert Pająk <pellared@hotmail.com>

Author: dmathieu

CHANGELOG.md

@@ -35,6 +35,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Return spec-compliant `TraceIdRatioBased` description. This is a breaking behavioral change, but it is necessary to
   make the implementation [spec-compliant](https://opentelemetry.io/docs/specs/otel/trace/sdk/#traceidratiobased). (#8027)
 - Fix a race condition in `go.opentelemetry.io/otel/sdk/metric` where the lastvalue aggregation could collect the value 0 even when no zero-value measurements were recorded. (#8056)
+- `WithHostID` detector in `go.opentelemetry.io/otel/sdk/resource` to use full path for `kenv` command on BSD. (#8113)
 - Fix missing `request.GetBody` in `go.opentelemetry.io/otel/exporters/otlp/otlplog/otlploghttp` to correctly handle HTTP2 GOAWAY frame. (#8096)
 
 <!-- Released section -->

sdk/resource/host_id.go

@@ -31,19 +31,19 @@ type hostIDReaderBSD struct {
 	readFile    fileReader
 }
 
-// read attempts to read the machine-id from /etc/hostid. If not found it will
-// execute `kenv -q smbios.system.uuid`. If neither location yields an id an
-// error will be returned.
+// read attempts to read the machine-id from /etc/hostid.
+// If not found it will execute: /bin/kenv -q smbios.system.uuid.
+// If neither location yields an id an error will be returned.
 func (r *hostIDReaderBSD) read() (string, error) {
 	if result, err := r.readFile("/etc/hostid"); err == nil {
 		return strings.TrimSpace(result), nil
 	}
 
-	if result, err := r.execCommand("kenv", "-q", "smbios.system.uuid"); err == nil {
+	if result, err := r.execCommand("/bin/kenv", "-q", "smbios.system.uuid"); err == nil {
 		return strings.TrimSpace(result), nil
 	}
 
-	return "", errors.New("host id not found in: /etc/hostid or kenv")
+	return "", errors.New("host id not found in: /etc/hostid or /bin/kenv")
 }
 
 // hostIDReaderDarwin implements hostIDReader.