scripts: Fix check for services running when upgrading.

When upgrading from a pre-4.0 release, scripts/stop-server logic would
check whether supervisord configuration files were present to
determine what it needed to restart, but only considered paths to
those files that are introduced in Zulip 4.0.

scripts/lib/zulip_tools.py

@@ -600,7 +600,21 @@ def is_vagrant_env_host(path: str) -> bool:
 
 
 def has_application_server() -> bool:
-    return os.path.exists("/etc/supervisor/conf.d/zulip/zulip.conf")
+    return (
+        # Current path
+        os.path.exists("/etc/supervisor/conf.d/zulip/zulip.conf")
+        # Old path, relevant for upgrades
+        or os.path.exists("/etc/supervisor/conf.d/zulip.conf")
+    )
+
+
+def has_process_fts_updates() -> bool:
+    return (
+        # Current path
+        os.path.exists("/etc/supervisor/conf.d/zulip/zulip_db.conf")
+        # Old path, relevant for upgrades
+        or os.path.exists("/etc/supervisor/conf.d/zulip_db.conf")
+    )
 
 
 def deport(netloc: str) -> str:

scripts/restart-server

@@ -17,6 +17,7 @@ from scripts.lib.zulip_tools import (
     get_config_file,
     get_tornado_ports,
     has_application_server,
+    has_process_fts_updates,
     overwrite_symlink,
 )
 
@@ -90,7 +91,7 @@ if has_application_server():
             worker_status.check_returncode()
         workers.extend(status_line.split()[0] for status_line in worker_status.stdout.splitlines())
 
-if os.path.exists("/etc/supervisor/conf.d/zulip/zulip_db.conf"):
+if has_process_fts_updates():
     workers.append("process-fts-updates")
 
 if action == "restart" and len(workers) > 0:

scripts/stop-server

@@ -7,7 +7,13 @@ import sys
 import time
 
 sys.path.append(os.path.join(os.path.dirname(__file__), ".."))
-from scripts.lib.zulip_tools import ENDC, OKGREEN, WARNING, has_application_server
+from scripts.lib.zulip_tools import (
+    ENDC,
+    OKGREEN,
+    WARNING,
+    has_application_server,
+    has_process_fts_updates,
+)
 
 deploy_path = os.path.realpath(os.path.join(os.path.dirname(__file__), ".."))
 os.chdir(deploy_path)
@@ -22,7 +28,7 @@ logging.basicConfig(format="%(asctime)s stop-server: %(message)s", level=logging
 services = []
 
 # Start with the least-critical services:
-if os.path.exists("/etc/supervisor/conf.d/zulip/zulip_db.conf"):
+if has_process_fts_updates():
     services.append("process-fts-updates")
 
 if has_application_server():