Simplify sync by cloning in a temporary directory

See elekto-io#72 and elekto-io#73

Author: mscherer

config.py

@@ -83,12 +83,10 @@
 # application via gitops, see the design documentation [/docs/DESIGN.md] for
 # more detailed information on working.
 # - REMOTE : Remote repository url
-# - PATH : Where the meta repository is cloned (if development is local)
 # - DEPLOYMENT : mode of deployment (local, sidecar)
 META = {
     'REMOTE': env('META_REPO'),
     'ELECDIR': env('ELECTION_DIR'),
-    'PATH': env('META_PATH', 'meta'),
     'DEPLOYMENT': env('META_DEPLOYMENT', 'local'),
     'BRANCH': env('META_BRANCH', 'main'),
     'SECRET': env('META_SECRET')

console

@@ -81,10 +81,8 @@ if __name__ == "__main__":
 
         print('# ----------- Syncing the meta with the database ----------- #')
 
-        if not os.path.exists(backend.META) or not os.path.isdir(backend.META):
-            backend.clone()
+        backend.clone()
 
-        backend.pull()
 
         print(sync(SESSION, meta.Election.all()))
         exit()

elekto/controllers/webhook.py

@@ -27,8 +27,5 @@
 @csrf.exempt
 def webhook_sync():
     backend = meta.Meta(APP.config['META'])
-    if not os.path.exists(backend.META) or not os.path.isdir(backend.META):
-        backend.clone()
-    else:
-        backend.pull()
+    backend.clone()
     return sync(SESSION, meta.Election.all())

elekto/models/meta.py

@@ -16,6 +16,8 @@
 
 import os
 import random
+import subprocess
+import tempfile
 import flask as F
 
 from datetime import datetime
@@ -32,20 +34,18 @@ class Meta:
     """
 
     def __init__(self, config):
-        self.META = os.path.abspath(config['PATH'])
+        # keep this, as it ties the directory to the object lifecycle
+        self.TMPDIR = tempfile.TemporaryDirectory("elekto")
+        self.META = self.TMPDIR.name
         self.ELECDIR = config['ELECDIR']
         self.REMOTE = config['REMOTE']
         self.BRANCH = config['BRANCH']
         self.SECRET = config['SECRET']
         self.git = '/usr/bin/git'
-        self.pref = "/usr/bin/git --git-dir={}/.git --work-tree={}\
-            ".format(self.META, self.META)
 
     def clone(self):
-        os.system('{} clone -b {} -- {} {}'.format(self.git, self.BRANCH, self.REMOTE, self.META))
+        subprocess.check_call([self.git, 'clone', '-b', self.BRANCH, '--', self.REMOTE, self.META])
 
-    def pull(self):
-        os.system('{} pull --ff-only origin {}'.format(self.pref, self.BRANCH))
 
 
 class Election(Meta):