Force the admin password from CM_INITIAL_ADMIN_PASS on every boot (#24)

Upstream scripts/docker/create_superuser.py only acts when no superuser
exists. Every VFB instance boots by restoring a *.pgsql dump that already
contains superusers, so that check always fails and CM_INITIAL_ADMIN_PASS
is silently ignored - the admin password is whatever the dump happened to
carry. It has therefore never been applied to any seeded instance, and the
passwords have drifted apart (l1em no longer matches the others).

Postgres data lives inside the container and only /backup persists, so a
manual correction is wiped on the next recreate. Reapplying on boot is the
only durable fix.

modify_superuser.py now reads CM_INITIAL_ADMIN_USER/CM_INITIAL_ADMIN_PASS
instead of carrying a hardcoded password hash, and is idempotent: it writes
only when the password or the staff/active flags actually differ, and is a
no-op when the variable is unset or the user does not exist.

init.sh invokes it in the background, since catmaid-entry.sh never returns,
polling for up to 10 minutes while the fixture loads and the database comes
up. Loaders are unaffected - they start from an empty /backup, so upstream
create_superuser.py already applies the variable correctly there.

Author: Robbie1977

init.sh

@@ -12,6 +12,30 @@ tail -F /var/log/postgresql/postgresql-11-main.log &
 # is set. No-op when empty. Idempotent across container restarts.
 python3 /opt/VFB/inject_gtm.py || echo "inject_ga: non-fatal failure, continuing"
 
+# Force the admin password to match CM_INITIAL_ADMIN_PASS.
+#
+# Upstream create_superuser.py only creates a superuser when none exists, so on
+# an instance restored from a /backup dump it does nothing and the environment
+# variable is silently ignored - the admin password stays whatever the dump
+# carried. Postgres data lives inside the container, so a manual fix is lost on
+# the next recreate; this reapplies it on every boot.
+#
+# catmaid-entry.sh below never returns, so wait for the database in the
+# background. modify_superuser.py is idempotent and a no-op when the password
+# already matches or CM_INITIAL_ADMIN_PASS is unset.
+(
+  cd /home/django/projects || exit 0
+  for _ in $(seq 1 120); do
+    if printf '\n\n' | cat /opt/VFB/modify_superuser.py - \
+         | /home/env/bin/python manage.py shell 2>/dev/null \
+         | grep '^modify_superuser:'; then
+      exit 0
+    fi
+    sleep 5
+  done
+  echo "modify_superuser: database not ready after 10 minutes, giving up" >&2
+) &
+
 if [ -e /backup/*.pgsql ]
 then
   export DB_FIXTURE=true

modify_superuser.py

@@ -1,4 +1,42 @@
+# -*- coding: utf-8 -*-
+# Force CATMAID's admin account to the password given in the environment.
+#
+# Upstream scripts/docker/create_superuser.py only acts when NO superuser
+# exists:
+#
+#     if User.objects.filter(is_superuser=True).count() == 0:
+#         User.objects.create_superuser(...)
+#
+# Every VFB instance boots by restoring a *.pgsql dump that already contains
+# superusers, so that check always fails and CM_INITIAL_ADMIN_PASS is silently
+# ignored. The admin password is then whatever the dump happened to carry,
+# which drifts per instance and cannot be corrected durably by setting the
+# environment variable.
+#
+# This script closes that gap. It is idempotent: it only writes when the
+# password (or the staff/active flags) actually differ, so a boot that is
+# already correct touches nothing.
+#
+# Piped into `manage.py shell` by init.sh; the file needs a trailing blank
+# line so the input stream ends cleanly.
+import os
+
 from django.contrib.auth.models import User
-user = User.objects.get(username='admin')
-user.password=u'pbkdf2_sha256$24000$OlTY7BRHr07a$Pw2rmvcwaFAx0o/ogfagwptO9/R4PtmoA407MNFYUSU='
-user.save()
+
+admin_user = os.environ.get('CM_INITIAL_ADMIN_USER', 'admin')
+admin_pass = os.environ.get('CM_INITIAL_ADMIN_PASS')
+
+if not admin_pass:
+    print('modify_superuser: CM_INITIAL_ADMIN_PASS is not set, leaving the password unchanged')
+else:
+    user = User.objects.filter(username=admin_user).first()
+    if user is None:
+        print('modify_superuser: no user %r on this instance, nothing to do' % admin_user)
+    elif user.check_password(admin_pass) and user.is_staff and user.is_active:
+        print('modify_superuser: %r already matches the environment, no change' % admin_user)
+    else:
+        user.set_password(admin_pass)
+        user.is_staff = True
+        user.is_active = True
+        user.save()
+        print('modify_superuser: reset the password for %r from the environment' % admin_user)