Add dynamic_proxy_prefix configuration

Normally the proxy binds to :8800 and runs containers under
:8800/ipython/... which is great... until you have an upstream proxy
like apache wrapping that at the url FQDN/ipython and suddenly your
cookies aren't available because they're specific to /galaxy.

Thus, when an upstream proxy is in use, we correct the proxy's path to:
with :8800/{cookie_path}/gie_proxy/ipython/... which behaves much more
nicely with upstraem proxies.

config/galaxy.ini.sample

@@ -574,6 +574,12 @@ nglims_config_file = tool-data/nglims.yaml
 # nodejs to wrap connections in SSL).
 #dynamic_proxy_external_proxy=False
 
+# Additionally, when the dynamic proxy is proxied by an upstream server, you'll
+# want to specify a prefixed URL so both Galaxy and the proxy reside under the
+# same path that your cookies are under. This will result in a url like
+# https://FQDN/galaxy-prefix/gie_proxy for proxying
+#dynamic_proxy_prefix=gie_proxy
+
 # -- Logging and Debugging
 
 # If True, Galaxy will attempt to configure a simple root logger if a

lib/galaxy/config.py

@@ -443,6 +443,7 @@ def __init__( self, **kwargs ):
         self.dynamic_proxy_bind_port = int( kwargs.get( "dynamic_proxy_bind_port", "8800" ) )
         self.dynamic_proxy_bind_ip = kwargs.get( "dynamic_proxy_bind_ip", "0.0.0.0" )
         self.dynamic_proxy_external_proxy = string_as_bool( kwargs.get( "dynamic_proxy_external_proxy", "False" ) )
+        self.dynamic_proxy_prefix = kwargs.get( "dynamic_proxy_prefix", "gie_proxy" )
 
         # Default chunk size for chunkable datatypes -- 64k
         self.display_chunk_size = int( kwargs.get( 'display_chunk_size', 65536) )

lib/galaxy/web/proxy/__init__.py

@@ -17,7 +17,9 @@
 class ProxyManager(object):
 
     def __init__( self, config ):
-        for option in [ "manage_dynamic_proxy", "dynamic_proxy_bind_port", "dynamic_proxy_bind_ip", "dynamic_proxy_debug", "dynamic_proxy_external_proxy" ]:
+        for option in ["manage_dynamic_proxy", "dynamic_proxy_bind_port",
+                       "dynamic_proxy_bind_ip", "dynamic_proxy_debug",
+                       "dynamic_proxy_external_proxy", "dynamic_proxy_prefix"]:
             setattr( self, option, getattr( config, option ) )
         self.launch_by = "node"  # TODO: Support docker
         if self.manage_dynamic_proxy:
@@ -44,9 +46,9 @@ def setup_proxy( self, trans, host=DEFAULT_PROXY_TO_HOST, port=None ):
             host = host[0:host.index(':')]
         scheme = trans.request.scheme
         if not self.dynamic_proxy_external_proxy:
-            proxy_url = '%s://%s:%d' % (scheme, host, self.dynamic_proxy_bind_port)
+            proxy_url = '%s://%s:%d/%s' % (scheme, host, self.dynamic_proxy_bind_port, self.dynamic_proxy_prefix)
         else:
-            proxy_url = '%s://%s' % (scheme, host)
+            proxy_url = '%s://%s/%s' % (scheme, host, self.dynamic_proxy_prefix)
         return {
             'proxy_url': proxy_url,
             'proxied_port': proxy_requests.port,