unpack-zulip: Do 2-step upgrade for version <= 1.3.10.

If the current version is less than or equal to 1.3.10, first
recommend an upgrade to the version 1.4.3 and then to the final
version.

scripts/lib/unpack-zulip

@@ -10,7 +10,9 @@ import glob
 os.environ["PYTHONUNBUFFERED"] = "y"
 
 sys.path.append(os.path.join(os.path.dirname(__file__), '..', ".."))
-from scripts.lib.zulip_tools import DEPLOYMENTS_DIR, FAIL, ENDC, make_deploy_path
+from scripts.lib.zulip_tools import DEPLOYMENTS_DIR, FAIL, ENDC, make_deploy_path, \
+    get_deployment_version, is_invalid_upgrade
+import version
 
 if len(sys.argv) != 2:
     print(FAIL + "Usage: %s <tarball>" % (sys.argv[0],) + ENDC)
@@ -22,6 +24,17 @@ deploy_path = make_deploy_path()
 
 extract_path = tempfile.mkdtemp()
 subprocess.check_call(["tar", "-xf", tarball_path, "-C", extract_path])
+
+new_version = get_deployment_version(extract_path)
+current_version = version.ZULIP_VERSION
+if is_invalid_upgrade(current_version, new_version):
+    print(FAIL +
+          "Your current version is very old. Please first upgrade to version "
+          "1.4.3 and then upgrade to {}.".format(new_version) +
+          ENDC)
+    subprocess.check_call(["rm", "-r", extract_path])
+    sys.exit(1)
+
 subprocess.check_call(["mv", glob.glob(os.path.join(extract_path, "zulip-server-*"))[0], deploy_path])
 subprocess.check_call(["rmdir", extract_path])
 subprocess.check_call(["ln", "-nsf", "/etc/zulip/settings.py",

scripts/lib/zulip_tools.py

@@ -4,6 +4,7 @@ import datetime
 import errno
 import os
 import pwd
+import re
 import shutil
 import subprocess
 import sys
@@ -25,6 +26,25 @@ ENDC = '\033[0m'
 BLACKONYELLOW = '\x1b[0;30;43m'
 WHITEONRED = '\x1b[0;37;41m'
 
+def get_deployment_version(extract_path):
+    # type: (str) -> str
+    version = '0.0.0'
+    for item in os.listdir(extract_path):
+        item_path = os.path.join(extract_path, item)
+        if item.startswith('zulip-server') and os.path.isdir(item_path):
+            with open(os.path.join(item_path, 'version.py')) as f:
+                result = re.search('ZULIP_VERSION = "(.*)"', f.read())
+                if result:
+                    version = result.groups()[0]
+            break
+    return version
+
+def is_invalid_upgrade(current_version, new_version):
+    # type: (str, str) -> bool
+    if new_version > '1.4.3' and current_version <= '1.3.10':
+        return True
+    return False
+
 def subprocess_text_output(args):
     # type: (Sequence[str]) -> str
     return subprocess.check_output(args, universal_newlines=True).strip()