# HG changeset patch
# User Mads Kiilerich <mads@kiilerich.com>
# Date 2019-12-29 01:41:47
# Node ID ba6418fde72f286a95f207fb14eeeee2ac788a55
# Parent  488b52cad8905eac29645b8dad77117bfd73184d

git: more elegant handling of installed pre/post-receive hook failing on direct repo access

The hook would fail with a long backtrace when get_hook_environment raise an error exception.

Instead, as first thing in the entry point from the hook, catch that situation
and report it nicely before "quietly" skipping the hook:

    [mk@here myrepo]$ git push
    Enumerating objects: 3, done.
    Counting objects: 100% (3/3), done.
    Writing objects: 100% (3/3), 204 bytes | 204.00 KiB/s, done.
    Total 3 (delta 0), reused 0 (delta 0)
    remote: Skipping Kallithea Git post-recieve hook 'hooks/post-receive'.
    remote: Git was apparently not invoked by Kallithea: Environment variable KALLITHEA_EXTRAS not found
    To /tmp/somerepo
     * [new branch]      master -> master
    [mk@here myrepo]$

We could be paranoid and let it (and the pre hook) fail ... but that doesn't
seem helpful.

Reported by Edmund Wong at [1].

[1] https://lists.sfconservancy.org/pipermail/kallithea-general/2019q4/003071.html

diff --git a/kallithea/lib/hooks.py b/kallithea/lib/hooks.py
--- a/kallithea/lib/hooks.py
+++ b/kallithea/lib/hooks.py
@@ -27,12 +27,13 @@ Original author and date, and relevant c
 
 import binascii
 import os
+import sys
 import time
 
 from kallithea.lib import helpers as h
 from kallithea.lib.exceptions import UserCreationError
 from kallithea.lib.utils import action_logger, make_ui, setup_cache_regions
-from kallithea.lib.utils2 import get_hook_environment, safe_str, safe_unicode
+from kallithea.lib.utils2 import HookEnvironmentError, get_hook_environment, safe_str, safe_unicode
 from kallithea.lib.vcs.backends.base import EmptyChangeset
 from kallithea.lib.vcs.utils.hgcompat import revrange
 from kallithea.model.db import Repository, User
@@ -340,7 +341,11 @@ def handle_git_pre_receive(repo_path, gi
 
 def handle_git_post_receive(repo_path, git_stdin_lines):
     """Called from Git post-receive hook"""
-    baseui, repo = _hook_environment(repo_path)
+    try:
+        baseui, repo = _hook_environment(repo_path)
+    except HookEnvironmentError as e:
+        sys.stderr.write("Skipping Kallithea Git post-recieve hook %r.\nGit was apparently not invoked by Kallithea: %s\n" % (sys.argv[0], e))
+        return 0
 
     # the post push hook should never use the cached instance
     scm_repo = repo.scm_instance_no_cache()
diff --git a/kallithea/lib/utils2.py b/kallithea/lib/utils2.py
--- a/kallithea/lib/utils2.py
+++ b/kallithea/lib/utils2.py
@@ -522,6 +522,9 @@ def obfuscate_url_pw(engine):
     return str(_url)
 
 
+class HookEnvironmentError(Exception): pass
+
+
 def get_hook_environment():
     """
     Get hook context by deserializing the global KALLITHEA_EXTRAS environment
@@ -535,13 +538,13 @@ def get_hook_environment():
     try:
         extras = json.loads(os.environ['KALLITHEA_EXTRAS'])
     except KeyError:
-        raise Exception("Environment variable KALLITHEA_EXTRAS not found")
+        raise HookEnvironmentError("Environment variable KALLITHEA_EXTRAS not found")
 
     try:
         for k in ['username', 'repository', 'scm', 'action', 'ip']:
             extras[k]
     except KeyError:
-        raise Exception('Missing key %s in KALLITHEA_EXTRAS %s' % (k, extras))
+        raise HookEnvironmentError('Missing key %s in KALLITHEA_EXTRAS %s' % (k, extras))
 
     return AttributeDict(extras)