Replace Inline::Python with a light Python function server

sandbox_starcheck

@@ -23,12 +23,6 @@ then
     exit 1
 fi
 
-PERL_INLINE_DIRECTORY=`mktemp -d -t starcheck_inline.XXXXXX` || exit 1
-export PERL_INLINE_DIRECTORY
 perl -I ${DIR}/starcheck/src/lib ${DIR}/starcheck/src/starcheck.pl "$@"
 SC_STATUS=$?
-if [[ -d $PERL_INLINE_DIRECTORY && $PERL_INLINE_DIRECTORY =~ .*starcheck_inline.* ]];
-then
-    rm -r $PERL_INLINE_DIRECTORY
-fi
 exit $SC_STATUS

starcheck/pcad_att_check.py

@@ -9,10 +9,6 @@
 
 
 def check_characteristics_date(ofls_characteristics_file, ref_date=None):
-    # de_bytetring these inputs from Perl -> Python 3
-    ofls_characteristics_file = ofls_characteristics_file.decode()
-    if ref_date is not None:
-        ref_date = ref_date.decode()
     match = re.search(r'CHARACTERIS_(\d\d)([A-Z]{3})(\d\d)', ofls_characteristics_file)
     if not match:
         return False

starcheck/server.py

@@ -0,0 +1,109 @@
+import collections
+import importlib
+import json
+import logging
+import socketserver
+import sys
+import traceback
+
+from ska_helpers.logging import basic_logger
+
+logger = basic_logger(__name__, level="INFO")
+
+HOST = "localhost"
+KEY = None
+
+func_calls = collections.Counter()
+
+
+class PythonServer(socketserver.TCPServer):
+    timeout = 180
+
+    def handle_timeout(self) -> None:
+        print(f"SERVER: starcheck python server timeout after {self.timeout}s idle",
+              file=sys.stderr)
+        # self.shutdown()  # DOES NOT WORK, just hangs
+        sys.exit(1)
+
+
+class MyTCPHandler(socketserver.StreamRequestHandler):
+    """
+    The request handler class for our server.
+
+    It is instantiated once per connection to the server, and must
+    override the handle() method to implement communication to the
+    client.
+    """
+
+    def handle(self):
+        # self.request is the TCP socket connected to the client
+        data = self.rfile.readline()
+        logger.debug(f"SERVER receive: {data.decode('utf-8')}")
+
+        # Decode self.data from JSON
+        cmd = json.loads(data)
+
+        if cmd["key"] != KEY:
+            logger.ERROR(f"SERVER: bad key {cmd['key']!r}")
+            return
+
+        logger.debug(f"SERVER receive func: {cmd['func']}")
+        logger.debug(f"SERVER receive args: {cmd['args']}")
+        logger.debug(f"SERVER receive kwargs: {cmd['kwargs']}")
+
+        exc = None
+
+        # For security reasons, only allow functions in the public API of starcheck module
+        if cmd["func"] == "get_server_calls":
+            # Sort func calls by the items in the counter
+            result = dict(func_calls)
+        else:
+            func_calls[cmd["func"]] += 1
+            parts = cmd["func"].split(".")
+            package = ".".join(["starcheck"] + parts[:-1])
+            func = parts[-1]
+            module = importlib.import_module(package)
+            func = getattr(module, func)
+            args = cmd["args"]
+            kwargs = cmd["kwargs"]
+
+            try:
+                result = func(*args, **kwargs)
+            except Exception:
+                result = None
+                exc = traceback.format_exc()
+
+        resp = json.dumps({"result": result, "exception": exc})
+        logger.debug(f"SERVER send: {resp}")
+
+        self.request.sendall(resp.encode("utf-8"))
+
+
+def main():
+    global KEY
+
+    # Read a line from STDIN
+    port = int(sys.stdin.readline().strip())
+    KEY = sys.stdin.readline().strip()
+    loglevel = sys.stdin.readline().strip()
+
+    logmap = {'0': logging.CRITICAL,
+              '1': logging.WARNING,
+              '2': logging.INFO}
+    if loglevel in logmap:
+        logger.setLevel(logmap[loglevel])
+    if int(loglevel) > 2:
+        logger.setLevel(logging.DEBUG)
+
+    logger.info(f"SERVER: starting on port {port}")    
+
+    # Create the server, binding to localhost on supplied port
+    with PythonServer((HOST, port), MyTCPHandler) as server:
+        # Activate the server; this will keep running until you
+        # interrupt the program with Ctrl-C
+        while True:
+            server.handle_request()
+
+
+if __name__ == "__main__":
+    main()