Pretalx

Open source tooling for events and conferences

This project is funded by NLnet through these subgrants:

Options

services.ngi-pretalx
services.ngi-pretalx.celery.backendFile

Path to a file that contains the location (connection URI) of Celery backend. If you use a standard Redis-based setup, the file should contain redis://127.0.0.1/1 or similar. Check the documentation https://docs.celeryq.dev/en/stable/getting-started/backends-and-brokers/redis.html. Consider using a secret managing scheme such as agenix or sops-nix to generate this file.

Type:
null or absolute path
Default:
null
services.ngi-pretalx.celery.brokerFile

Path to a file that contains the location (connection URI) of Celery broker. If you use a standard Redis-based setup, the file should contain redis://127.0.0.1/2 or similar. Check the documentation https://docs.celeryq.dev/en/stable/getting-started/backends-and-brokers/redis.html. Consider using a secret managing scheme such as agenix or sops-nix to generate this file.

Type:
null or absolute path
Default:
null
services.ngi-pretalx.celery.enable

Whether to enable Enable support for Celery..

Type:
boolean
Default:
false
services.ngi-pretalx.celery.extraArgs

Extra arguments to pass to celery. See https://docs.celeryq.dev/en/stable/reference/cli.html#celery-worker for more info.

Type:
list of string
Default:
[ ]
services.ngi-pretalx.database.backend

The default is SQLite ("sqlite3"), which is not a production database. Please use a database like PostgreSQL ("postgresql") or MySQL ("mysql").

Type:
one of "postgresql", "mysql", "sqlite3"
Default:
"sqlite3"
services.ngi-pretalx.database.host

Database host, or path to a socket (if you use PostgreSQL or MySQL). For local PostgreSQL authentication, you can leave this variable empty.

Type:
null or string
Default:
null
services.ngi-pretalx.database.name

Database name. If you use SQLite, this is the filesystem path to the database file.

Type:
string
Default:
"pretalx"
services.ngi-pretalx.database.passwordFile

Path to a file containing the database password. If you use PostgreSQL, consider using its peer authentication and not setting a password. Consider using a secret managing scheme such as agenix or sops-nix to generate this file.

Type:
null or absolute path
Default:
null
services.ngi-pretalx.database.port

Database port (e.g. 5432 for PostgreSQL or 3306 for MySQL).

Type:
null or signed integer
Default:
null
services.ngi-pretalx.database.user

Database user that pretalx should connect as.

Type:
null or string
Default:
null
services.ngi-pretalx.enable

Whether to enable Enable pretalx server..

Type:
boolean
Default:
false
services.ngi-pretalx.extraConfig

Extra configuration to be appended to the generated pretalx configuration file. See https://docs.pretalx.org/administrator/configure.html for all options.

Type:
attribute set
Default:
{ }
services.ngi-pretalx.filesystem.data

Path that is the base for all other directories (see options media, static, logs). Unless you have a compelling reason to keep other files apart, setting this option is the easiest way to configure file storage.

Type:
absolute path
Default:
"/var/lib/pretalx/data"
services.ngi-pretalx.filesystem.logs

Directory that contains logged data. It needs to be writable by the pretalx process.

Type:
string
Default:
"/var/lib/pretalx/data/logs"
services.ngi-pretalx.filesystem.media

Directory that contains user generated files. It needs to be writable by the pretalx process.

Type:
string
Default:
"/var/lib/pretalx/data/media"
services.ngi-pretalx.filesystem.static

Directory that contains static files. It needs to be writable by the pretalx process. pretalx will put files there.

Type:
string
Default:
"${config.services.ngi-pretalx.package.static}"
services.ngi-pretalx.group

Group that contains the system user that executes pretalx.

Type:
string
Default:
"pretalx"
services.ngi-pretalx.gunicorn.extraArgs

Command line arguments passed to Gunicorn server.

Type:
string
Default:
"--workers=4 --max-requests=1200 --max-requests-jitter=50 --log-level=error"
services.ngi-pretalx.init.admin.email

E-mail address of the administrator.

Type:
string
services.ngi-pretalx.init.admin.passwordFile

Path to a file containing the administrator password. Consider using a secret managing scheme such as agenix or sops-nix to generate this file.

Type:
absolute path
services.ngi-pretalx.init.organiser.name

Name of the conference organiser.

Type:
string
services.ngi-pretalx.init.organiser.slug

Slug of the conference organiser (to be used in URLs).

Type:
string
services.ngi-pretalx.locale.language_code

Default locale.

Type:
string
Default:
"en"
services.ngi-pretalx.locale.time_zone

Default time zone as a pytz name.

You can use following code to generate the full list of timezone names:

import pytz

print(pytz.all_timezones)
Type:
string
Default:
"UTC"
services.ngi-pretalx.logging.email

E-mail address (or comma-separated list of addresses) to send system logs to.

Type:
string
services.ngi-pretalx.logging.email_level

Log level to start sending emails at.

Type:
one of "DEBUG", "INFO", "WARNING", "ERROR", "CRITICAL"
Default:
"ERROR"
services.ngi-pretalx.logging.enable

Whether to enable Enable support for logging..

Type:
boolean
Default:
false
services.ngi-pretalx.mail.enable

Enable sending e-mails from pretalx.

Type:
boolean
Default:
true
services.ngi-pretalx.mail.from

Fall-back sender address, e.g. for when pretalx sends event-independent e-mails.

Type:
string
Default:
"admin@localhost"
services.ngi-pretalx.mail.host

Hostname of the SMTP server for sending e-mails.

Type:
string
Default:
"localhost"
services.ngi-pretalx.mail.passwordFile

Path to a file containing the password for SMTP server authentication. Consider using a secret managing scheme such as agenix or sops-nix to generate this file.

Type:
absolute path
services.ngi-pretalx.mail.port

TCP port of the SMTP server for sending e-mails.

Type:
signed integer
Default:
25
services.ngi-pretalx.mail.ssl

Whether to use SSL for sending mail.

Type:
boolean
Default:
true
services.ngi-pretalx.mail.tls

Whether to use TLS for sending mail.

Type:
boolean
Default:
false
services.ngi-pretalx.mail.user

Username for SMTP server authentication.

Type:
string
services.ngi-pretalx.nginx

nginx virtualHost settings.

Type:
submodule
Default:
{ }
services.ngi-pretalx.nginx.acmeFallbackHost

Host which to proxy requests to if ACME challenge is not found. Useful if you want multiple hosts to be able to verify the same domain name.

With this option, you could request certificates for the present domain with an ACME client that is running on another host, which you would specify here.

Type:
null or string
Default:
null
services.ngi-pretalx.nginx.acmeRoot

Directory for the ACME challenge, which is public. Don't put certs or keys in here. Set to null to inherit from config.security.acme.

Type:
null or string
Default:
"/var/lib/acme/acme-challenge"
services.ngi-pretalx.nginx.addSSL

Whether to enable HTTPS in addition to plain HTTP. This will set defaults for listen to listen on all interfaces on the respective default ports (80, 443).

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.basicAuth

Basic Auth protection for a vhost.

WARNING: This is implemented to store the password in plain text in the Nix store.

Type:
attribute set of string
Default:
{ }
services.ngi-pretalx.nginx.basicAuthFile

Basic Auth password file for a vhost. Can be created by running {command}nix-shell --packages apacheHttpd --run 'htpasswd -B -c FILENAME USERNAME'.

Type:
null or absolute path
Default:
null
services.ngi-pretalx.nginx.default

Makes this vhost the default.

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.enableACME

Whether to ask Let's Encrypt to sign a certificate for this vhost. Alternately, you can use an existing certificate through {option}useACMEHost.

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.extraConfig

These lines go to the end of the vhost verbatim.

Type:
strings concatenated with "\n"
Default:
""
services.ngi-pretalx.nginx.forceSSL

Whether to add a separate nginx server block that redirects (defaults to 301, configurable with redirectCode) all plain HTTP traffic to HTTPS. This will set defaults for listen to listen on all interfaces on the respective default ports (80, 443), where the non-SSL listens are used for the redirect vhosts.

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.globalRedirect

If set, all requests for this host are redirected (defaults to 301, configurable with redirectCode) to the given hostname.

Type:
null or string
Default:
null
services.ngi-pretalx.nginx.http2

Whether to enable the HTTP/2 protocol. Note that (as of writing) due to nginx's implementation, to disable HTTP/2 you have to disable it on all vhosts that use a given IP address / port. If there is one server block configured to enable http2, then it is enabled for all server blocks on this IP. See https://stackoverflow.com/a/39466948/263061.

Type:
boolean
Default:
true
services.ngi-pretalx.nginx.http3

Whether to enable the HTTP/3 protocol. This requires using pkgs.nginxQuic package which can be achieved by setting services.nginx.package = pkgs.nginxQuic; and activate the QUIC transport protocol services.nginx.virtualHosts.<name>.quic = true;. Note that HTTP/3 support is experimental and not yet recommended for production. Read more at https://quic.nginx.org/ HTTP/3 availability must be manually advertised, preferably in each location block.

Type:
boolean
Default:
true
services.ngi-pretalx.nginx.http3_hq

Whether to enable the HTTP/0.9 protocol negotiation used in QUIC interoperability tests. This requires using pkgs.nginxQuic package which can be achieved by setting services.nginx.package = pkgs.nginxQuic; and activate the QUIC transport protocol services.nginx.virtualHosts.<name>.quic = true;. Note that special application protocol support is experimental and not yet recommended for production. Read more at https://quic.nginx.org/

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.kTLS

Whether to enable kTLS support. Implementing TLS in the kernel (kTLS) improves performance by significantly reducing the need for copying operations between user space and the kernel. Required Nginx version 1.21.4 or later.

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.listen

Listen addresses and ports for this virtual host. IPv6 addresses must be enclosed in square brackets. Note: this option overrides addSSL and onlySSL.

If you only want to set the addresses manually and not the ports, take a look at listenAddresses.

Type:
list of (submodule)
Default:
[ ]
services.ngi-pretalx.nginx.listen.*.addr

Listen address.

Type:
string
services.ngi-pretalx.nginx.listen.*.extraParameters

Extra parameters of this listen directive.

Type:
list of string
Default:
[ ]
services.ngi-pretalx.nginx.listen.*.port

Port number to listen on. If unset and the listen address is not a socket then nginx defaults to 80.

Type:
null or 16 bit unsigned integer; between 0 and 65535 (both inclusive)
Default:
null
services.ngi-pretalx.nginx.listen.*.proxyProtocol

Enable PROXY protocol.

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.listen.*.ssl

Enable SSL.

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.listenAddresses

Listen addresses for this virtual host. Compared to listen this only sets the addresses and the ports are chosen automatically.

Note: This option overrides enableIPv6

Type:
list of string
Default:
[ ]
services.ngi-pretalx.nginx.locations

Declarative location config

Type:
attribute set of (submodule)
Default:
{ }
services.ngi-pretalx.nginx.locations..alias

Alias directory for requests.

Type:
null or absolute path
Default:
null
services.ngi-pretalx.nginx.locations..basicAuth

Basic Auth protection for a vhost.

WARNING: This is implemented to store the password in plain text in the Nix store.

Type:
attribute set of string
Default:
{ }
services.ngi-pretalx.nginx.locations..basicAuthFile

Basic Auth password file for a vhost. Can be created by running {command}nix-shell --packages apacheHttpd --run 'htpasswd -B -c FILENAME USERNAME'.

Type:
null or absolute path
Default:
null
services.ngi-pretalx.nginx.locations..extraConfig

These lines go to the end of the location verbatim.

Type:
strings concatenated with "\n"
Default:
""
services.ngi-pretalx.nginx.locations..fastcgiParams

FastCGI parameters to override. Unlike in the Nginx configuration file, overriding only some default parameters won't unset the default values for other parameters.

Type:
attribute set of (string or absolute path)
Default:
{ }
services.ngi-pretalx.nginx.locations..index

Adds index directive.

Type:
null or string
Default:
null
services.ngi-pretalx.nginx.locations..priority

Order of this location block in relation to the others in the vhost. The semantics are the same as with lib.mkOrder. Smaller values have a greater priority.

Type:
signed integer
Default:
1000
services.ngi-pretalx.nginx.locations..proxyPass

Adds proxy_pass directive and sets recommended proxy headers if recommendedProxySettings is enabled.

Type:
null or string
Default:
null
services.ngi-pretalx.nginx.locations..proxyWebsockets

Whether to support proxying websocket connections with HTTP/1.1.

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.locations..recommendedProxySettings

Enable recommended proxy settings.

Type:
boolean
Default:
config.services.nginx.recommendedProxySettings
services.ngi-pretalx.nginx.locations..recommendedUwsgiSettings

Enable recommended uwsgi settings.

Type:
boolean
Default:
config.services.nginx.recommendedUwsgiSettings
services.ngi-pretalx.nginx.locations..return

Adds a return directive, for e.g. redirections.

Type:
null or string or signed integer
Default:
null
services.ngi-pretalx.nginx.locations..root

Root directory for requests.

Type:
null or absolute path
Default:
null
services.ngi-pretalx.nginx.locations..tryFiles

Adds try_files directive.

Type:
null or string
Default:
null
services.ngi-pretalx.nginx.locations..uwsgiPass

Adds uwsgi_pass directive and sets recommended proxy headers if recommendedUwsgiSettings is enabled.

Type:
null or string
Default:
null
services.ngi-pretalx.nginx.onlySSL

Whether to enable HTTPS and reject plain HTTP connections. This will set defaults for listen to listen on all interfaces on port 443.

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.quic

Whether to enable the QUIC transport protocol. This requires using pkgs.nginxQuic package which can be achieved by setting services.nginx.package = pkgs.nginxQuic;. Note that QUIC support is experimental and not yet recommended for production. Read more at https://quic.nginx.org/

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.redirectCode

HTTP status used by globalRedirect and forceSSL. Possible usecases include temporary (302, 307) redirects, keeping the request method and body (307, 308), or explicitly resetting the method to GET (303). See https://developer.mozilla.org/en-US/docs/Web/HTTP/Redirections.

Type:
integer between 300 and 399 (both inclusive)
Default:
301
services.ngi-pretalx.nginx.rejectSSL

Whether to listen for and reject all HTTPS connections to this vhost. Useful in default server blocks to avoid serving the certificate for another vhost. Uses the ssl_reject_handshake directive available in nginx versions 1.19.4 and above.

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.reuseport

Create an individual listening socket . It is required to specify only once on one of the hosts.

Type:
boolean
Default:
false
services.ngi-pretalx.nginx.root

The path of the web root directory.

Type:
null or absolute path
Default:
null
services.ngi-pretalx.nginx.serverAliases

Additional names of virtual hosts served by this virtual host configuration.

Type:
list of string
Default:
[ ]
services.ngi-pretalx.nginx.serverName

Name of this virtual host. Defaults to attribute name in virtualHosts.

Type:
null or string
Default:
null
services.ngi-pretalx.nginx.sslCertificate

Path to server SSL certificate.

Type:
absolute path
services.ngi-pretalx.nginx.sslCertificateKey

Path to server SSL certificate key.

Type:
absolute path
services.ngi-pretalx.nginx.sslTrustedCertificate

Path to root SSL certificate for stapling and client certificates.

Type:
null or absolute path
Default:
null
services.ngi-pretalx.nginx.useACMEHost

A host of an existing Let's Encrypt certificate to use. This is useful if you have many subdomains and want to avoid hitting the rate limit. Alternately, you can generate a certificate through {option}enableACME. Note that this option does not create any certificates, nor it does add subdomains to existing ones – you will need to create them manually using .

Type:
null or string
Default:
null
services.ngi-pretalx.package

The pretalxFull package to use.

Type:
package
Default:
pkgs.pretalxFull
services.ngi-pretalx.redis.enable

Whether to enable Enable support for Redis..

Type:
boolean
Default:
false
services.ngi-pretalx.redis.locationFile

Path to a file that contains the location (connection URI) of Redis server, if you want to use it as a cache. Contents of the file: redis://[:password]@127.0.0.1:6379/1 would be sensible, or unix://[:password]@/path/to/socket.sock?db=0 if you prefer to use sockets. Consider using a secret managing scheme such as agenix or sops-nix to generate this file.

Type:
absolute path
services.ngi-pretalx.redis.session

Whether to use Redis as session storage.

Type:
boolean
Default:
false
services.ngi-pretalx.site.csp

Use this setting to update the CSP security headers. See https://docs.pretalx.org/administrator/configure.html#csp-csp-script-csp-style-csp-img-csp-form.

Type:
null or string
Default:
null
services.ngi-pretalx.site.csp_form

Use this setting to update the CSP security headers. See https://docs.pretalx.org/administrator/configure.html#csp-csp-script-csp-style-csp-img-csp-form.

Type:
null or string
Default:
null
services.ngi-pretalx.site.csp_img

Use this setting to update the CSP security headers. See https://docs.pretalx.org/administrator/configure.html#csp-csp-script-csp-style-csp-img-csp-form.

Type:
null or string
Default:
null
services.ngi-pretalx.site.csp_script

Use this setting to update the CSP security headers. See https://docs.pretalx.org/administrator/configure.html#csp-csp-script-csp-style-csp-img-csp-form.

Type:
null or string
Default:
null
services.ngi-pretalx.site.csp_style

Use this setting to update the CSP security headers. See https://docs.pretalx.org/administrator/configure.html#csp-csp-script-csp-style-csp-img-csp-form.

Type:
null or string
Default:
null
services.ngi-pretalx.site.media

Path that is appended to the site URL to address media files (all files uploaded by users or generated by pretalx).

Type:
string
Default:
"/media/"
services.ngi-pretalx.site.secretFile

Path to a file containing a secret key that the Django web framework uses for cryptographic signing. See https://docs.pretalx.org/administrator/configure.html#secret. Consider using a secret managing scheme such as agenix or sops-nix to generate this file.

Type:
null or absolute path
Default:
null
services.ngi-pretalx.site.static

Path that is appended to the site URL to address static files.

Type:
string
Default:
"/static/"
services.ngi-pretalx.site.url

URL for pretalx. pretalx uses this value when it has to render full URLs, for example in emails or feeds. It is also used to determine the allowed incoming hosts.

Type:
string
Default:
"http://options.invalid"
services.ngi-pretalx.user

Username of the system user that should own files and services related to pretalx.

Type:
string
Default:
"pretalx"

Examples

Basic configuration for Pretalx, incl. secret management with SOPS, excl. database settings. 
{
  config,
  pkgs,
  ...
}:
{
  networking = {
    firewall.allowedTCPPorts = [ config.services.nginx.defaultHTTPListenPort ];
    hostName = "server";
    domain = "example.com";
  };

  sops = {
    # See <https://github.com/Mic92/sops-nix>.

    age.keyFile = "/dev/null"; # For a production configuration, set this option.
    defaultSopsFile = "/dev/null"; # For a production configuration, set this option.
    validateSopsFiles = false; # For a production configuration, remove this line.

    secrets =
      let
        pretalxSecret = {
          owner = config.services.ngi-pretalx.user;
          group = config.services.ngi-pretalx.group;
        };
      in
      {
        "pretalx/database/password" = pretalxSecret;
        "pretalx/redis/location" = pretalxSecret;
        "pretalx/init/admin/password" = pretalxSecret;
        "pretalx/celery/backend" = pretalxSecret;
        "pretalx/celery/broker" = pretalxSecret;
      };
  };

  services = {
    ngi-pretalx = {
      enable = true;
      package = pkgs.pretalxFull;
      nginx = {
        # For a production configuration use this attribute set to configure the virtual host for pretalx.
      };
      database = {
        user = "pretalx";
        passwordFile = config.sops.secrets."pretalx/database/password".path;
      };
      redis = {
        enable = true;
        locationFile = config.sops.secrets."pretalx/redis/location".path;
      };
      celery = {
        enable = true;
        backendFile = config.sops.secrets."pretalx/celery/backend".path;
        brokerFile = config.sops.secrets."pretalx/celery/broker".path;
      };
      init = {
        admin = {
          email = "pretalx@localhost";
          passwordFile = config.sops.secrets."pretalx/init/admin/password".path;
        };
        organiser = {
          name = "NGI Packages";
          slug = "ngipkgs";
        };
      };
      mail.enable = false;
    };

    redis.servers."pretalx" = {
      enable = true;
      user = config.services.ngi-pretalx.user;
    };

    nginx = {
      enable = true;
      recommendedTlsSettings = true;
      recommendedOptimisation = true;
      recommendedGzipSettings = true;
      recommendedProxySettings = true;
    };
  };
}
Supplementary to `base.nix`, adds database configuration for MySQL. 
{
  config,
  pkgs,
  ...
}:
{
  services = {
    ngi-pretalx.database = {
      backend = "mysql";
      host = "/var/run/mysqld/mysqld.sock";
      user = "pretalx";
    };

    mysql = {
      enable = true;
      package = pkgs.mariadb;
      ensureUsers = [
        {
          name = config.services.ngi-pretalx.database.user;
          ensurePermissions."${config.services.ngi-pretalx.database.name}.*" = "ALL PRIVILEGES";
        }
      ];
      ensureDatabases = [ config.services.ngi-pretalx.database.name ];
    };
  };
}
Supplementary to `base.nix`, adds database configuration for PostgreSQL. 
{ config, ... }:
{
  services = {
    ngi-pretalx.database = {
      backend = "postgresql";
      user = "pretalx";
    };

    postgresql = {
      enable = true;
      authentication = "local all all trust";
      ensureUsers = [
        {
          name = config.services.ngi-pretalx.database.user;
          ensureDBOwnership = true;
        }
      ];
      ensureDatabases = [ config.services.ngi-pretalx.database.name ];
    };
  };
}