[COMMIT osv master] firecracker: enhance firecracker.py to save/restore terminal

[Commit Bot]

From: Waldemar Kozaczuk <jwkoz...@gmail.com>
Committer: Waldemar Kozaczuk <jwkoz...@gmail.com>
Branch: master

firecracker: enhance firecracker.py to save/restore terminal

This patch borrows similar logic from run.py to save and
restore terminal line settings to prevent firecracker.py mess up
the terminal.

Signed-off-by: Waldemar Kozaczuk <jwkoz...@gmail.com>

---
diff --git a/scripts/firecracker.py b/scripts/firecracker.py
--- a/scripts/firecracker.py
+++ b/scripts/firecracker.py
@@ -6,6 +6,7 @@
import stat
import json
import subprocess
+import signal
import time
import argparse
import re
@@ -16,6 +17,19 @@

verbose = False

+stty_params = None
+
+devnull = open('/dev/null', 'w')
+
+def stty_save():
+ global stty_params
+ p = subprocess.Popen(["stty", "-g"], stdout=subprocess.PIPE,
stderr=devnull)
+ stty_params, err = p.communicate()
+ stty_params = stty_params.strip()
+
+def stty_restore():
+ if stty_params:
+ subprocess.call(["stty", stty_params], stderr=devnull)

class ApiException(Exception):
pass
@@ -212,13 +226,15 @@ def start_firecracker(firecracker_path, socket_path):
os.unlink(socket_path)

# Start firecracker process to communicate over specified UNIX socket
file
+ stty_save()
return subprocess.Popen([firecracker_path, '--api-sock', socket_path],
stdout=sys.stdout, stderr=subprocess.STDOUT)

def start_firecracker_with_no_api(firecracker_path,
firecracker_config_json):
# Start firecracker process and pass configuration JSON as a file
api_file = tempfile.NamedTemporaryFile(delete=False)
api_file.write(firecracker_config_json)
+ stty_save()
return
subprocess.Popen([firecracker_path, "--no-api", "--config-file",
api_file.name],
stdout=sys.stdout, stderr=subprocess.STDOUT),
api_file.name

@@ -313,15 +329,23 @@ def main(options):
except ApiException as e:
print("Failed to make firecracker API call: %s." % e)
firecracker.kill()
+ stty_restore()
exit(-1)

except Exception as e:
print("Failed to run OSv on firecracker due to: ({0}):
{1} !!!".format(e.errno, e.strerror))
firecracker.kill()
+ stty_restore()
exit(-1)

print_time("Waiting for firecracker process to terminate")
- firecracker.wait()
+ try:
+ firecracker.wait()
+ except KeyboardInterrupt:
+ os.kill(firecracker.pid, signal.SIGINT)
+
+ stty_restore()
+
if options.api_less:
os.unlink(config_file_path)
print_time("End")