Create localhost echo server (#61)

Co-authored-by: Xiaodong Li <[email protected]>

executable-monitor/executable-monitor.py

@@ -73,24 +73,28 @@
     logging.info(f"Storing logs in: {log_dir}")
     logging.info(f"Timeout (seconds): {args.timeout_seconds}")
 
-    exe = subprocess.Popen([exe_abs_path], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, universal_newlines=True)
-
-    cur_time_seconds = time.time()
-    timeout_time_seconds = cur_time_seconds + args.timeout_seconds
+    # Initialize values
     timeout_occurred = False
-
     exe_exit_status = None
     exe_exitted = False
-
     success_line_found = False
-    cur_line_ouput = 1
+    wait_for_exit = args.success_exit_status is not None
 
-    wait_for_exit = args.success_exit_status is not None       
+    # Launch the executable
+    exe = subprocess.Popen([exe_abs_path], stdout=subprocess.PIPE, stderr=subprocess.STDOUT, universal_newlines=True)
+
+    cur_time_seconds = time.time()
+    timeout_time_seconds = cur_time_seconds + args.timeout_seconds
 
     logging.info("START OF DEVICE OUTPUT\n")
 
     while not (timeout_occurred or exe_exitted or (not wait_for_exit and success_line_found)):
 
+        # Check if executable exitted
+        exe_exit_status = exe.poll()
+        if exe_exit_status is not None:
+            exe_exitted = True
+
         # Read executable's stdout and write to stdout and logfile
         exe_stdout_line = exe.stdout.readline()
         logging.info(exe_stdout_line)
@@ -99,16 +103,14 @@
         if args.success_line is not None and args.success_line in exe_stdout_line:
             success_line_found = True
 
-        # Check if executable exitted
-        exe_exit_status = exe.poll()
-        if exe_exit_status is not None:
-            exe_exitted = True
-
         # Check for timeout
         cur_time_seconds = time.time()
         if cur_time_seconds >= timeout_time_seconds:
             timeout_occurred = True
 
+        # Sleep for a short duration between loops to not steal all system resources
+        time.sleep(.1)
+
     if not exe_exitted:
         exe.kill()
 

localhost-echo-server/action.yml

@@ -0,0 +1,16 @@
+name: 'Localhost Echo Server'
+description: 'Starts an echo server using Python.'
+
+inputs:
+  port_number:
+    description: "Port for echo server."
+    required: True
+
+runs:
+  using: "composite"
+  steps: 
+      - name: Run localhost Echo server
+        run: |
+          python3 --version
+          python3 $GITHUB_ACTION_PATH/local_echo_server.py --port_number=${{ inputs.port_number }} &
+        shell: bash

localhost-echo-server/local_echo_server.py

@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+
+import asyncio
+import logging
+import os
+from argparse import ArgumentParser
+
+logger = logging.getLogger('echoserver')
+
+async def echo_handler(reader, writer):
+  address = writer.get_extra_info('peername')
+  logger.debug('accept: %s', address)
+  message = await reader.readline()
+  writer.write(message)
+  await writer.drain()
+  writer.close()
+
+if __name__ == '__main__':
+  parser = ArgumentParser(description='Localhost Echo server.')
+  parser.add_argument('--port_number',
+                      type=int,
+                      required=True,
+                      help='Port for echo server.')
+  args = parser.parse_args()
+  logging.basicConfig()
+  logger.setLevel(logging.DEBUG)
+  loop = asyncio.get_event_loop()
+  factory = asyncio.start_server(
+    echo_handler,
+    os.environ.get('HOST'),
+    os.environ.get('PORT', args.port_number)
+  )
+  server = loop.run_until_complete(factory)
+  try:
+    loop.run_forever()
+  except KeyboardInterrupt:
+    pass
+  server.close()
+  loop.run_until_complete(server.wait_closed())
+  loop.close()