upgrade-zulip-from-git: Refactor deploy_options logic to zulip_tools.py.

This a preparatory commit moving the deploy_options logic to
zulip_tools.py so it can be imported and used in upgrade-zulip.

scripts/lib/upgrade-zulip-from-git

@@ -6,25 +6,20 @@ import subprocess
 import logging
 import time
 import argparse
+from typing import List
+import configparser
 
-config_file = configparser.RawConfigParser()
-config_file.read("/etc/zulip/zulip.conf")
 LOCAL_GIT_CACHE_DIR = '/srv/zulip.git'
-
-try:
-    remote_url = config_file.get('deployment', 'git_repo_url')
-except (configparser.NoSectionError, configparser.NoOptionError):
-    remote_url = "https://github.com/zulip/zulip.git"
-try:
-    deploy_options = config_file.get('deployment', 'deploy_options').strip().split()
-except (configparser.NoSectionError, configparser.NoOptionError):
-    deploy_options = []
-
 os.environ["PYTHONUNBUFFERED"] = "y"
 
 sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..'))
 from scripts.lib.zulip_tools import DEPLOYMENTS_DIR, FAIL, WARNING, ENDC, make_deploy_path, \
-    get_deployment_lock, overwrite_symlink, release_deployment_lock, su_to_zulip, assert_running_as_root
+    get_deployment_lock, overwrite_symlink, release_deployment_lock, su_to_zulip, assert_running_as_root, \
+    get_config_file, get_deploy_options, get_config
+
+config_file = get_config_file()
+deploy_options = get_deploy_options(config_file)
+remote_url = get_config(config_file, 'deployment', 'git_repo_url', "https://github.com/zulip/zulip.git")
 
 assert_running_as_root(strip_lib_from_paths=True)
 

scripts/lib/zulip_tools.py

@@ -15,9 +15,10 @@ import tempfile
 import time
 import json
 import uuid
+import configparser
 
 if False:
-    from typing import Sequence, Set, Any, Dict, List
+    from typing import Sequence, Set, Any, Dict, List, Optional
 
 DEPLOYMENTS_DIR = "/home/zulip/deployments"
 LOCK_DIR = os.path.join(DEPLOYMENTS_DIR, "lock")
@@ -410,3 +411,18 @@ def assert_running_as_root(strip_lib_from_paths: bool=False) -> None:
     if not is_root():
         print("{} must be run as root.".format(script_name))
         sys.exit(1)
+
+def get_config(config_file, section, key, default_value=""):
+    # type: (configparser.RawConfigParser, str, str, str) -> str
+    if config_file.has_option(section, key):
+        return config_file.get(section, key)
+    return default_value
+
+def get_config_file() -> configparser.RawConfigParser:
+    config_file = configparser.RawConfigParser()
+    config_file.read("/etc/zulip/zulip.conf")
+    return config_file
+
+def get_deploy_options(config_file):
+    # type: (configparser.RawConfigParser) -> List[str]
+    return get_config(config_file, 'deployment', 'deploy_options', "").strip().split()