Warn when cqlsh does not match the server version it was built with

Patch by brandonwilliams; reviewed by bereng for CASSANDRA-18745

.build/build-cqlsh.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!--
+  Licensed to the Apache Software Foundation (ASF) under one
+  or more contributor license agreements.  See the NOTICE file
+  distributed with this work for additional information
+  regarding copyright ownership.  The ASF licenses this file
+  to you under the Apache License, Version 2.0 (the
+  "License"); you may not use this file except in compliance
+  with the License.  You may obtain a copy of the License at
+
+      http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+-->
+<project basedir="." name="apache-cassandra-cqlsh-tasks"
+         xmlns:if="ant:if">
+    <target name="set-cqlsh-version">
+        <echo file="pylib/cqlshlib/serverversion.py" append="false">version = "${base.version}"${line.separator}</echo>
+    </target>
+</project>

CHANGES.txt

@@ -1,4 +1,5 @@
 3.0.30
+ * CQLSH emits a warning when the server version doesn't match (CASSANDRA-18745)
  * Fix missing speculative retries in tablestats (CASSANDRA-18767)
  * Fix Requires for Java for RPM package (CASSANDRA-18751)
  * Fix CQLSH online help topic link (CASSANDRA-17534)

bin/cqlsh.py

@@ -171,6 +171,7 @@ from cqlshlib.formatting import (DEFAULT_DATE_FORMAT, DEFAULT_NANOTIME_FORMAT,
                                  formatter_for)
 from cqlshlib.tracing import print_trace, print_trace_session
 from cqlshlib.util import get_file_encoding_bomsize, trim_if_present
+from cqlshlib.serverversion import version as build_version
 
 DEFAULT_HOST = '127.0.0.1'
 DEFAULT_PORT = 9042
@@ -797,6 +798,8 @@ class Shell(cmd.Cmd):
         if stdin is None:
             stdin = sys.stdin
 
+        self.check_build_versions()
+
         if tty:
             self.reset_prompt()
             self.report_connection()
@@ -816,6 +819,14 @@ class Shell(cmd.Cmd):
     def batch_mode(self):
         return not self.tty
 
+    def check_build_versions(self):
+        baseversion = self.connection_versions['build']
+        extra = baseversion.rfind('-')
+        if extra:
+            baseversion = baseversion[0:extra]
+        if baseversion != build_version:
+            print("WARNING: cqlsh was built against {}, but this server is {}.  All features may not work!".format(baseversion, build_version))
+
     @property
     def is_using_utf8(self):
         # utf8 encodings from https://docs.python.org/{2,3}/library/codecs.html

build.xml

@@ -684,7 +684,7 @@
     </target>
 
     <!-- create properties file with C version -->
-    <target name="createVersionPropFile">
+    <target name="createVersionPropFile" depends="set-cqlsh-version">
       <taskdef name="propertyfile" classname="org.apache.tools.ant.taskdefs.optional.PropertyFile"/>
       <mkdir dir="${version.properties.dir}"/>
       <propertyfile file="${version.properties.dir}/version.properties">
@@ -1970,4 +1970,5 @@
   <import file="${basedir}/.build/build-resolver.xml"/>
   <import file="${basedir}/.build/build-rat.xml"/>
   <import file="${basedir}/.build/build-owasp.xml"/>
+  <import file="${basedir}/.build/build-cqlsh.xml"/>
 </project>