Replace $DAEMON_VERSION and $DAEMON_SUBVERSION

in banner file.

RELEASE-NOTES

@@ -1,3 +1,16 @@
+version 0.7.15
+--------------
+
+The following meta variables in your banner file are now replaced in
+addition to $VERSION described in the notes to 0.17.11.  If you type
+getnetworkinfo in your daemon's debug console you will see what they
+are based on:
+
+- $DAEMON_VERSION is replaced with the daemon's version as a dot-separated
+  string.  For example "0.12.1".
+- $DAEMON_SUBVERSION is replaced with the daemon's user agent string.
+  For example, "/BitcoinUnlimited:0.12.1(EB16; AD4)/".
+
 version 0.7.14
 --------------
 

server/daemon.py

@@ -156,11 +156,15 @@ class Daemon(util.LoggedClass):
         '''Return the fee estimate for the given parameters.'''
         return await self._send_single('estimatefee', params)
 
+    async def getnetworkinfo(self):
+        '''Return the result of the 'getnetworkinfo' RPC call.'''
+        return await self._send_single('getnetworkinfo')
+
     async def relayfee(self):
         '''The minimum fee a low-priority tx must pay in order to be accepted
         to the daemon's memory pool.'''
-        net_info = await self._send_single('getnetworkinfo')
-        return net_info['relayfee']
+        network_info = await self.getnetworkinfo()
+        return network_info['relayfee']
 
     async def getrawtransaction(self, hex_hash):
         '''Return the serialized raw transaction with the given hash.'''

server/protocol.py

@@ -889,7 +889,17 @@ class ElectrumX(Session):
                 self.logger.error('reading banner file {}: {}'
                                   .format(self.env.banner_file, e))
             else:
-                banner = banner.replace('$VERSION', VERSION)
+                network_info = await self.daemon.getnetworkinfo()
+                version = network_info['version']
+                major, minor = divmod(version, 1000000)
+                minor, revision = divmod(minor, 10000)
+                revision //= 100
+                version = '{:d}.{:d}.{:d}'.format(major, minor, revision)
+                subversion = network_info['subversion']
+                banner = (banner.replace('$VERSION', VERSION)
+                          .replace('$DAEMON_VERSION', version)
+                          .replace('$DAEMON_SUBVERSION', subversion))
+
         return banner
 
     async def donation_address(self, params):