criu-ns: Add tests for criu-ns script (WIP)

These changes add test implementations for criu-ns script.

Fixes: #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

test/others/criu-ns/Makefile

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

test/others/criu-ns/run.py

@@ -0,0 +1,106 @@
+#!/usr/bin/env python
+
+import os
+import pty
+import shutil
+import subprocess
+import sys
+import time
+
+CR_NS = "../../../scripts/criu-ns"
+pid = 0
+
+
+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 create_dumpee(shell_job=False):
+    global pid
+    open("running", "w").close()
+    fd_m, fd_s = create_pty()
+    pid = os.fork()
+    if pid == 0:
+        if not shell_job:
+            os.setsid()
+            os.dup2(fd_s.fileno(), 0)
+            os.dup2(fd_s.fileno(), 1)
+            os.dup2(fd_s.fileno(), 2)
+        else:
+            fd_m.close()
+            fd_s.close()
+        while True:
+            if not os.access("running", os.F_OK):
+                sys.exit(0)
+            time.sleep(1)
+        sys.exit(1)
+
+
+def test_dump_and_restore_with_shell_job():
+    global pid
+    check_dumpdir()
+    create_dumpee(shell_job=True)
+
+    cmd = [CR_NS, "dump", "-D", "dumpdir", "-v4", "-o", "dump.log",
+           "--shell-job", "-t", str(pid)]
+    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 = [CR_NS, "restore", "-D", "dumpdir", "-v4", "-o",
+               "restore.log", "--shell-job"]
+        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):
+    global pid
+    check_dumpdir()
+    create_dumpee()
+
+    cmd = [CR_NS, "dump", "-D", "dumpdir", "-v4", "-o", "dump.log",
+           "-t", str(pid)]
+    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 = [CR_NS, "restore", "-D", "dumpdir", "-v4", "-o",
+                   "restore.log", "--restore-detached"]
+        else:
+            cmd = [CR_NS, "restore", "-D", "dumpdir", "-v4", "-o",
+                   "restore.log"]
+
+        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)