Add unixtime option

This adds an option to return the expiration date in unixtime (time
since epoch).

It's particularly useful for alerting or monitoring systems that do
their own calculation based on the metric they receive (and not based on
exit codes).

For instance you can use the following in zabbix 5.4:
- item: check_expire["-H","{HOST.CONN}","-u"]
- trigger: last(/check_expire["-H","{HOST.CONN}","-u"])-now()<2592000

Where 2592000 is 30 days in seconds.

check_expire

@@ -42,10 +42,11 @@ verbose = False
 domain = None
 critical_t = datetime.timedelta(days=2)
 warning_t = datetime.timedelta(days=7)
+unixtime = False
 # TODO implement timeout for HTTPS requests. -t option. Does Requests allow it?
 
 def usage(msg=None):
-    print("Usage: %s -H domain-name [-c critical -w warning]" % sys.argv[0], end="")
+    print("Usage: %s -H domain-name [-c critical -w warning -u unixtime]" % sys.argv[0], end="")
     if msg is not None and msg != "":
         print(" (%s)" % msg)
     else:
@@ -80,8 +81,8 @@ def ok(msg=None):
     sys.exit(STATE_OK)
 
 try:
-    optlist, args = getopt.getopt (sys.argv[1:], "c:hH:vVw:",
-                                   ["critical=", "expiration", "help", "verbose", "version", "warning="])
+    optlist, args = getopt.getopt (sys.argv[1:], "c:hH:vVw:u",
+                                   ["critical=", "expiration", "help", "verbose", "version", "warning=", "unixtime"])
     for option, value in optlist:
         if option == "--critical" or option == "-c":
             critical_t = datetime.timedelta(days=int(value))
@@ -97,6 +98,8 @@ try:
             sys.exit(STATE_OK)
         elif option == "--warning" or option == "-w":
             warning_t = datetime.timedelta(days=int(value))
+        elif option == "--unixtime" or option == "-u":
+            unixtime = True
         else:
             # Should never occur, it is trapped by getopt
             print("Unknown option %s" % option)
@@ -136,6 +139,9 @@ for event in rdap["events"]:
                     print("No recognized format for datetime \"%s\"" % event["eventDate"])
                     sys.exit(STATE_UNKNOWN)
         now = datetime.datetime.now(tz=UTCINFO)
+        if unixtime == True:
+            print(int(expiration.strftime("%s")))
+            sys.exit(STATE_OK)
         if expiration < now:
             error("domain %s is already expired (%s ago)" % (domain, (now-expiration)))
         rest = expiration-now
@@ -146,5 +152,3 @@ for event in rdap["events"]:
         else:
             ok("expires in %s." % (rest))
 error("No expiration found")
-
-