This packages answers an nginx auth subrequest by looking up the user/password in a database (mysql, postgresql, whatever sqlalchemy supports).
You'll need to provide the DSN and the query using a configuration file:
[default]
dsn = postgresql://localhost/myusers
query = SELECT password FROM users WHERE username = :username AND role = :x_required_role
password_hash = bcrypt
See the sqlalchemy documentation for supported DSNs. Note that you have to install the respective driver python package (mysql-python
, psycopg2
, etc.) yourself.
Settings beginning with sqlalchemy.
are stripped of that prefix and passed through to sqlalchemy.create_engine().
The query gets passed as SQL parameters the basic auth username
and password
as well as any request headers (lowercase, and -
replaced with _
). (If that is not flexible enough for your usecase, you'll have to run separate instances with specialized queries, for the time being).
The query must return the hashed password of the user. Since for simple cases you might get away with using the SQL functions provided by your database to hash the password (e.g. mysql WHERE password=encrypt(:password, password)
), but you can also specify any hash supported by passlib as the password_hash
to perform the comparison in Python (that's why we need the stored password hash from the database). You need to pip install passlib
to use this feature.
Then you need to set up an HTTP server, either with a dedicated process:
$ nginx-db-auth-serve --host localhost --port 8899 --config /path/to/config
or as a CGI script, if you have infrastructure for that set up anyway. Here's an example apache configuration snippet to do this:
ScriptAlias /nginx-auth /path/to/nginxdbauth/nginx-db-auth-cgi
<Location /nginx-auth>
SetEnv NGINXDBAUTH_CONFIG /path/to/config
CGIPassAuth On # apache >= 2.4.13
# SetEnv NGINXDBAUTH_LOGFILE /path/to/log # optional, for debugging
</Location>
Now you can set up a protected nginx location like this:
location /private/ {
auth_request /auth;
# ... define rest of location ...
}
location = /auth {
proxy_pass http://localhost:8899; # or http://mycgi/nginx-auth
proxy_pass_request_body off;
proxy_set_header Content-Length "";
proxy_set_header X-Required-Role "superuser";
proxy_set_header WWW-Authenticate "Basic realm=\"my realm\"";
}
The WWW-Authenticate
header sent by nginx will simply be echoed back on 401 requests (since as far as I can tell, nginx does not provide another way to set the realm string in the auth_request
case).