criu-ns: Add tests for criu-ns script

These changes add test implementations for criu-ns script.

Fixes: checkpoint-restore#1909

Signed-off-by: Dhanuka Warusadura <csx@tuta.io>

scripts/ci/run-ci-tests.sh

@@ -259,6 +259,7 @@ if [ -n "$TRAVIS" ] || [ -n "$CIRCLECI" ]; then
        # GitHub Actions (and Cirrus CI) does not provide a real TTY and CRIU will fail with:
        # Error (criu/tty.c:1014): tty: Don't have tty to inherit session from, aborting
        make -C test/others/shell-job/ run
+       make -C test/others/criu-ns/ run
 fi
 make -C test/others/skip-file-rwx-check/ run
 make -C test/others/rpc/ run

scripts/criu-ns

@@ -80,8 +80,20 @@ def run_criu(args):
     Spawn CRIU binary
     """
     print(sys.argv)
-    os.execlp('criu', *['criu'] + args)
-    raise OSError(errno.ENOENT, "No such command")
+
+    if "--criu-binary" in args:
+        try:
+            path = args[args.index("--criu-binary") + 1]
+            args.remove("--criu-binary")
+            args.remove(path)
+            args.insert(0, "criu")
+            os.execv(path, args)
+            raise OSError(errno.ENOENT, "No such command")
+        except (ValueError, IndexError):
+            raise OSError(errno.ENOENT, "--criu-binary missing argument")
+    else:
+        os.execlp("criu", *["criu"] + args)
+        raise OSError(errno.ENOENT, "No such command")
 
 
 # pidns_holder creates a process that is reparented to the init.

test/others/criu-ns/Makefile

@@ -0,0 +1,2 @@
+run:
+	../../zdtm_ct run.py

test/others/criu-ns/run.py

@@ -0,0 +1,108 @@
+#!/usr/bin/env python
+
+import os
+import pty
+import shutil
+import subprocess
+import sys
+import time
+
+
+CRIU_BIN = "../../../criu/criu"
+CRIU_NS = "../../../scripts/criu-ns"
+
+
+def check_dumpdir():
+    if os.path.isdir("dumpdir"):
+        shutil.rmtree("dumpdir")
+    os.mkdir("dumpdir", 0o755)
+
+
+def create_pty():
+    fd_m, fd_s = pty.openpty()
+    return (os.fdopen(fd_m, "wb"), os.fdopen(fd_s, "wb"))
+
+
+def test_dump_and_restore_with_shell_job():
+    check_dumpdir()
+
+    open("running", "w").close()
+    fd_m, fd_s = create_pty()
+    pid = os.fork()
+    if pid == 0:
+        os.setsid()
+        while True:
+            if not os.access("running", os.F_OK):
+                sys.exit(0)
+            time.sleep(1)
+        sys.exit(1)
+
+    cmd = [CRIU_NS, "dump", "-D", "dumpdir", "-v", "--shell-job",
+           "-t", str(pid), "--criu-binary", CRIU_BIN]
+    ret = subprocess.Popen(cmd).wait()
+    if ret != 0:
+        sys.exit(ret)
+
+    os.unlink("running")
+    fd_m, fd_s = create_pty()
+    pid = os.fork()
+    if pid == 0:
+        cmd = [CRIU_NS, "restore", "-D", "dumpdir", "-v",
+               "--shell-job", "--criu-binary", CRIU_BIN]
+        ret = subprocess.Popen(cmd).wait()
+        if ret != 0:
+            sys.exit(ret)
+        os._exit(0)
+
+    os.waitpid(pid, 0)
+
+
+def test_dump_and_restore_without_shell_job(restore_detached=False):
+    check_dumpdir()
+
+    open("running", "w").close()
+    fd_m, fd_s = create_pty()
+    pid = os.fork()
+    if pid == 0:
+        os.setsid()
+        os.dup2(fd_s.fileno(), 0)
+        os.dup2(fd_s.fileno(), 1)
+        os.dup2(fd_s.fileno(), 2)
+        while True:
+            if not os.access("running", os.F_OK):
+                sys.exit(0)
+            time.sleep(1)
+        sys.exit(1)
+
+    cmd = [CRIU_NS, "dump", "-D", "dumpdir", "-v", "-t", str(pid),
+           "--criu-binary", CRIU_BIN]
+    ret = subprocess.Popen(cmd).wait()
+    if ret != 0:
+        sys.exit(ret)
+
+    os.unlink("running")
+    fd_m, fd_s = create_pty()
+    pid = os.fork()
+    if pid == 0:
+        os.setsid()
+
+        if restore_detached:
+            cmd = [CRIU_NS, "restore", "-D", "dumpdir", "-v",
+                   "--restore-detached", "--criu-binary",
+                   CRIU_BIN]
+        else:
+            cmd = [CRIU_NS, "restore", "-D", "dumpdir", "-v",
+                   "--criu-binary", CRIU_BIN]
+
+        ret = subprocess.Popen(cmd).wait()
+        if ret != 0:
+            sys.exit(ret)
+        os._exit(0)
+
+    os.waitpid(pid, 0)
+
+
+if __name__ == "__main__":
+    test_dump_and_restore_with_shell_job()
+    test_dump_and_restore_without_shell_job()
+    test_dump_and_restore_without_shell_job(restore_detached=True)