216ce3dce7eb7f0f4ad401e50f301136b17bc89a
max
  Mon Sep 9 07:17:42 2019 -0700
now outputing 429 when blocking in hgGeneGraph, refs #24094

diff --git src/hg/pyLib/hgLib.py src/hg/pyLib/hgLib.py
index 89564a5..191eed0 100644
--- src/hg/pyLib/hgLib.py
+++ src/hg/pyLib/hgLib.py
@@ -34,46 +34,46 @@
 import platform
 if "hgwdev" in platform.node():
     import cgitb
     cgitb.enable()
 
 # debug level: a number. the higher, the more debug info is printed
 # to see most debug messages, set to 1
 # another way to change this variable is by setting the URL variable "debug" to 1
 verboseLevel = 0
 
 cgiArgs = None
 
 # like in the kent tree, we keep track of whether we have already output the content-type line
 contentLineDone = False
 
-# the effective total delay that was added before showing the page
+# show the bot delay warning message before other printing is done?
 doWarnBot = False
 
 # two global variables: the first is the botDelay limit after which the page is slowed down and a warning is shown
 # the second is the limit after which the page is not shown anymore
 botDelayWarn = 1000
 botDelayBlock = 5000
 
 jksqlTrace = False
 
 def warn(format, *args):
     print (format % args)
 
-def errAbort(msg):
+def errAbort(msg, status=None):
     " show msg and abort. Like errAbort.c "
-    printContentType()
+    printContentType(status=status)
     print msg
     exit(0)
 
 def debug(level, msg):
     " output debug message with a given verbosity level "
     if verboseLevel >= level:
         printContentType()
         print(msg+"<br>")
         sys.stdout.flush()
  
 def parseConf(fname):
     " parse a hg.conf style file, return as dict key -> value (all strings) "
     conf = {}
     for line in open(fname):
         line = line.strip()
@@ -327,45 +327,57 @@
 </head>
     """
 
 def webStartGbNoBanner(prefix, title):
     " output the <head> part, largely copied from web.c / webStartGbNoBanner "
     print (getGbHeader() % (prefix, title, getNonce(), getNonce()))
 
 def runCmd(cmd, mustRun=True):
     " wrapper around system() that prints error messages. cmd preferably a list, not just a string. "
     import subprocess
     ret = subprocess.call(cmd)
     if ret!=0 and mustRun:
         errAbort("Could not run command %s" % cmd)
     return ret
 
-def printContentType(contType="text/html", fname=None):
-    " print the HTTP Content-type header line with an optional file name. Also print bot delay note. "
+def printContentType(contType="text/html", status=None, fname=None):
+    """
+    print the HTTP Content-type header line with an optional file name for downloads.
+    Also optionally prints the bot delay note. The argument 'status' must be an int.
+    """
     global contentLineDone
     if not contentLineDone:
         contentLineDone = True
         print("Content-type: %s; charset=utf-8" % contType)
 
+        if status:
+            if status==400:
+                print("Status: 400 Bad Request")
+            elif status==429:
+                print("Status: 429 Too Many Requests")
+            else:
+                raise Exception("Unknown status code, please update hgLib.py")
+
         if fname is not None:
             print("Content-Disposition: attachment; filename=%s" % fname)
-        print
+
+        print  # this newline is essential, it means: end of header lines
 
     if doWarnBot:
         print ("<div style='background-color:yellow; border:2px solid black'>")
         print ("We have a suspicion that you are an automated web bot software, not a real user. ")
-        print ("To keep our site fast for other users, we have slowed down this page. ")
+        print ("To keep our site fast for other users, we have slowed down this page by %d milliseconds. ")
         print ("The slowdown will gradually disappear. ")
         print ("If you think this is a mistake, please contact us at genome-www@soe.ucsc.edu. ")
         print ("Also note that all data for hgGeneGraph can be obtained through our public MySQL server and")
         print ("all our software source code is available and can be installed locally onto your own computer. ")
         print ("If you are unsure how to use these resources, do not hesitate to contact us.")
         print ("</div>")
 
 
 def queryBottleneck(host, port, ip):
     " contact UCSC-style bottleneck server to get current delay time. From hg/lib/botDelay.c "
     # send ip address
     import socket
     s =  socket.socket()
     s.connect((host, int(port)))
     msg = ip
@@ -392,40 +404,40 @@
     Using the hgsid makes little sense. It is more lenient than the C version.
     """
     import time
     if "DOCUMENT_ROOT" not in os.environ: # skip if not called from Apache
         return
     global hgConf
     global doWarnBot
     hgConf = parseHgConf()
     if "bottleneck.host" not in hgConf:
         return
     ip = os.environ["REMOTE_ADDR"]
     delay = queryBottleneck(hgConf["bottleneck.host"], hgConf["bottleneck.port"], ip)
     debug(1, "Bottleneck delay: %d msecs" % delay)
 
     if delay>botDelayBlock:
-        errAbort("Too many HTTP requests. Your IP has been blocked to keep this website responsive for other users. "
+        errAbort("Too many HTTP requests and not enough delay between them. "
+        "Your IP has been blocked to keep this website responsive for other users. "
         "Please contact genome-www@soe.ucsc.edu to unblock your IP address. We can also help you obtain the data you need without "
-        "web crawling. ")
+        "web crawling. ", status=429)
         sys.exit(0)
 
     if delay>botDelayWarn:
         time.sleep(delay/1000.0)
         doWarnBot = True # = show warning message later in printContentType()
 
-
 def parseRa(text):
     " Parse ra-style string and return as dict name -> value "
     import string
     lines = text.split("\n")
     data = dict()
     for l in lines:
         if len(l)==0:
             continue
         key, val = string.split(l, " ", maxsplit=1)
         data[key] = val
     return data
 
 def lineFileNextRow(inFile):
     """
     parses tab-sep file with headers in first line. Yields collection.namedtuples.