Adding Sweeper to clean up expired tokens

roles/ipa/server/files/sweeper.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python3
+# Works with both python2 and python3; please preserve this property
+
+# Copyright (C) 2016 mod_auth_gssapi contributors - See COPYING for (C) terms
+
+# If one uses both sessions and unique ccache names, then the filesystem will
+# become littered with ccache files unless the accessed application cleans
+# them up itself.  This script will minimize ccache file proliferation by
+# removing any ccaches that have expired from the filesystem, and serves as an
+# example of how this cleaning can be performed.
+
+# gssproxy note: in order to sweep credentials, the sweeper needs to connect
+# to gssproxy as if it were mod_auth_gssapi.  In the configuration provided
+# with mod_auth_gssapi (80-httpd.conf), this just consists of matching the
+# gssproxy uid - so run it as the appropriate user (i.e., apache).  Custom
+# configurations require careful consideration of how to match the sweeper
+# connection to the correct service in gssproxy; this script is just an
+# example.  This script will not attempt to contact gssproxy unless -g is
+# passed.
+
+import argparse
+import os
+import stat
+import time
+
+# try importing this first to provide a more useful error message
+import gssapi
+del gssapi
+try:
+    from gssapi.raw import acquire_cred_from
+except ImportError:
+    print("Your GSSAPI does not provide cred store extension; exiting!")
+    exit(1)
+
+
+# process file as a ccache and indicate whether it is expired
+def should_delete(fname, t):
+    try:
+        # skip directories and other non-files
+        st = os.stat(fname)
+        if not stat.S_ISREG(st.st_mode):
+            return False
+
+        # ignore files that are newer than 30 minutes
+        if t - st.st_mtime < 30 * 60:
+            return False
+
+        creds = acquire_cred_from({b"ccache": fname.encode("UTF-8")})
+    except FileNotFoundError:
+        # someone else did the work for us
+        return False
+    except Exception as e:
+        print("Not deleting %s due to error %s" % (fname, e))
+        return False
+
+    return creds.lifetime == 0
+
+
+if __name__ == "__main__":
+    parser = argparse.ArgumentParser(description="Sweep expired ccaches")
+    parser.add_argument("-g", dest="gssproxy", action="store_true",
+                        help="is gssproxy in use (default: no)")
+    parser.add_argument("dirs", nargs='+')
+    args = parser.parse_args()
+
+    if args.gssproxy:
+        os.environ["GSS_USE_PROXY"] = "yes"
+        os.environ["GSSPROXY_BEHAVIOR"] = "REMOTE_FIRST"
+
+    print("System looks okay; running sweeper...")
+
+    t = time.time()
+
+    for basedir in args.dirs:
+        os.chdir(basedir)
+        print("Sweeping %s" % basedir)
+
+        for fname in os.listdir(basedir):
+            if should_delete(fname, t):
+                os.unlink(fname)
+
+    print("Sweeper finished successfully!")
+    exit(0)
+

roles/ipa/server/tasks/main.yml

@@ -675,3 +675,22 @@
   tags:
   - ipa/server
   - config
+
+- name: Copy sweeper script to /usr/local/bin/
+  copy:
+    src: sweeper.py
+    dest: /usr/local/bin/sweeper
+    mode: 0755
+  tags:
+    - ipa/server
+    - config
+
+- name: Set sweeper script on a cron schedule
+  cron:
+    name: "clean up mod_auth_gssapi tokens"
+    hour: "3"
+    user: root
+    job: "python3 sweeper"
+  tags:
+    - ipa/server
+    - config