test/sandbox: migrate tests

This significantly improves performance, removing overhead of nix,
python, and virtualisation. Running this in an unprivileged container
required patching the kernel, but since special runner setup was already
needed, that was an acceptable tradeoff.

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 13 insertions, 10 deletions

diff --git a/test/internal/testsuite/proc.go b/test/internal/testsuite/proc.go
index f2ad8857..e7ef1aed 100644
--- a/test/internal/testsuite/proc.go
+++ b/test/internal/testsuite/proc.go
@@ -10,6 +10,8 @@ import (
 	"strings"
 	"syscall"
 	"unsafe"
+
+	"hakurei.app/fhs"
 )
 
 // Stat represents status information read from /proc/pid/stat.
@@ -144,13 +146,9 @@ type Stat struct {
 	CGuestTime int
 }
 
-// fhsProc points to a virtual kernel file system exposing the process list and
-// other functionality.
-const fhsProc = "/proc/"
-
 // Executable is like [os.Executable], but for the process referred to by s.
 func (s *Stat) Executable() (string, error) {
-	path, err := os.Readlink(filepath.Join(fhsProc, strconv.Itoa(s.PID), "exe"))
+	path, err := os.Readlink(filepath.Join(fhs.Proc, strconv.Itoa(s.PID), "exe"))
 
 	// When the executable has been deleted then Readlink returns a
 	// path appended with " (deleted)".
@@ -159,7 +157,7 @@ func (s *Stat) Executable() (string, error) {
 
 // Stat populates stat with the proc filesystem entry referred to by s.
 func (s *Stat) Stat(stat *syscall.Stat_t) (err error) {
-	err = syscall.Stat(filepath.Join(fhsProc, strconv.Itoa(s.PID)), stat)
+	err = syscall.Stat(filepath.Join(fhs.Proc, strconv.Itoa(s.PID)), stat)
 	if err != nil {
 		err = os.NewSyscallError("stat", err)
 	}
@@ -168,7 +166,7 @@ func (s *Stat) Stat(stat *syscall.Stat_t) (err error) {
 
 // Args reads arguments of the process referred to by s.
 func (s *Stat) Args() ([]string, error) {
-	p, err := os.ReadFile(filepath.Join(fhsProc, strconv.Itoa(s.PID), "cmdline"))
+	p, err := os.ReadFile(filepath.Join(fhs.Proc, strconv.Itoa(s.PID), "cmdline"))
 	if err != nil {
 		return nil, err
 	}
@@ -286,6 +284,11 @@ type StatScanner struct {
 	err error
 }
 
+// IsNotExist returns whether an error is [os.ErrNotExist] or ESRCH.
+func IsNotExist(err error) bool {
+	return errors.Is(err, os.ErrNotExist) || errors.Is(err, syscall.ESRCH)
+}
+
 // Scan reads a process status information entry. It returns false if an
 // unrecoverable error is encountered, after which Scan no longer scans new
 // entries.
@@ -295,7 +298,7 @@ func (s *StatScanner) Scan() bool {
 	}
 
 	if s.wrapped = s.i == len(s.dents); s.wrapped {
-		if s.dents, s.err = os.ReadDir(fhsProc); s.err != nil {
+		if s.dents, s.err = os.ReadDir(fhs.Proc); s.err != nil {
 			return false
 		}
 		s.i = 0
@@ -318,9 +321,9 @@ func (s *StatScanner) Scan() bool {
 		}
 
 		var p []byte
-		p, err = os.ReadFile(filepath.Join(fhsProc, dent.Name(), "stat"))
+		p, err = os.ReadFile(filepath.Join(fhs.Proc, dent.Name(), "stat"))
 		if err != nil {
-			if errors.Is(err, os.ErrNotExist) || errors.Is(err, syscall.ESRCH) {
+			if IsNotExist(err) {
 				continue
 			}
 			s.err = err