hooks: Switch to passing values through the environment.

puppet/zulip/files/hooks/post-deploy.d/sentry.hook

@@ -1,6 +1,4 @@
 #!/usr/bin/env bash
-# Arguments: OLD_COMMIT NEW_COMMIT ...where both are `git describe`
-# output or tag names.  The CWD will be the new deploy directory.
 
 set -e
 set -u

puppet/zulip/files/hooks/pre-deploy.d/sentry.hook

@@ -1,6 +1,4 @@
 #!/usr/bin/env bash
-# Arguments: OLD_COMMIT NEW_COMMIT ...where both are `git describe`
-# output or tag names.  The CWD will be the new deploy directory.
 
 set -e
 set -u
@@ -42,8 +40,6 @@ if ! which sentry-cli >/dev/null; then
     exit 0
 fi
 
-new_version="$2"
-
 merge_base=""
 if [ "$(git rev-parse --is-inside-work-tree 2>/dev/null || true)" = "true" ]; then
     # Extract the merge-base that tools/cache-zulip-git-version
@@ -57,7 +53,7 @@ if [ "$(git rev-parse --is-inside-work-tree 2>/dev/null || true)" = "true" ]; th
     fi
 fi
 
-sentry_release="zulip-server@$new_version"
+sentry_release="zulip-server@$ZULIP_NEW_VERSION"
 echo "$sentry_release" >./sentry-release
 
 echo "sentry: Creating release $sentry_release"

scripts/lib/upgrade-zulip-stage-2

@@ -29,6 +29,7 @@ from scripts.lib.zulip_tools import (
     assert_running_as_root,
     get_config,
     get_config_file,
+    get_zulip_pwent,
     listening_publicly,
     parse_os_release,
     parse_version_from,
@@ -445,11 +446,22 @@ def run_hooks(kind: Literal["pre-deploy", "post-deploy"]) -> None:
     path = f"/etc/zulip/hooks/{kind}.d"
     if not os.path.exists(path):
         return
+    # Pass in, via environment variables, the old/new "version
+    # string" (which is a `git describe` output)
+    env = os.environ.copy()
+    env["ZULIP_OLD_VERSION"] = old_version
+    env["ZULIP_NEW_VERSION"] = NEW_ZULIP_VERSION
+
+    # preexec_fn=su_to_zulip normally handles this, but our explicit
+    # env overrides that
+    env["HOME"] = get_zulip_pwent().pw_dir
+
     for script_name in sorted(f for f in os.listdir(path) if f.endswith(".hook")):
         subprocess.check_call(
-            [os.path.join(path, script_name), old_version, NEW_ZULIP_VERSION],
+            [os.path.join(path, script_name)],
             cwd=deploy_path,
             preexec_fn=su_to_zulip,
+            env=env,
         )