Configuration

guillotina and its addons define a global configuration that is used. All of these settings are configurable by providing a JSON configuration file to the start script.

By default, the startup script looks for a config.yaml file. You can use a different file by using the -c option for the script like this: ./bin/guillotina -c myconfig.yaml.

Databases

Guillotina uses PostgreSQL out-of-the-box.

To configure available databases, use the databases option. Configuration options map 1-to-1 to database setup:

---
databases:
  - db:
      storage: postgresql
      dsn:
        scheme: postgres
        dbname: guillotina
        user: postgres
        host: localhost
        password: ''
        port: 5432
      read_only: false

Currently supported database drivers are:

  • postgresql
  • cockroach

Database configuration options

  • pool_size: Size of connection pool. (defaults to 13)
  • transaction_strategy: Connection strategy to use. See Transaction strategy_ for details. (defaults to resolve_readcommitted)
  • conn_acquire_timeout: How long to wait for connection to be freed up from pool. (defaults to 20)
  • cache_strategy: If you have something like guillotina_rediscache installed, you can configure here. (defaults to dummy)
  • objects_table_name: Table name to store object data. (defaults to objects)
  • blobs_table_name: Table name to store blob data. (defaults to blobs)

Static files

static:
  favicon.ico: static/favicon.ico
  static_files: module_name:static

These files will then be available on urls /favicon.ico and /static_files.

JavaScript Applications

We can also serve JS apps from guillotina. These will allow routing on your JS application without any extra configuration by returning the base directory index.html for every sub directory in the url.

Once there is SSR support in Python, guillotina will integrate with it through this as well.

jsapps:
  app: path/to/app

Root user password

root_user:
  password: root

CORS

cors:
  allow_origin:
    - "*"
  allow_methods:
    - GET
    - POST
    - DELETE
    - HEAD
    - PATCH
    - PUT
  allow_headers:
    - "*"
  expose_headers:
    - "*"
  allow_credentials: true
  max_age: 3660

Applications

To extend/override Guillotina, the applications configuration allows you to specify which to enable.

applications:
  - guillotina_elasticsearch

Async utilities

load_utilities:
  catalog:
    provides: guillotina.interfaces.ICatalogUtility
    factory: guillotina_elasticsearch.utility.ElasticSearchUtility
    settings: {}

Middleware

guillotina is built on aiohttp which provides support for middleware. You can provide an array of dotted names to use for your application.

middlewares:
  - guillotina_myaddon.Middleware

aiohttp settings

You can pass aiohttp_settings to configure the aiohttp server.

aiohttp_settings:
  client_max_size: 20971520

JWT Settings

If you want to enable JWT authentication, you’ll need to configure the JWT secret in Guillotina.

jwt:
  secret: foobar
  algorithm: HS256

Miscellaneous settings

  • port (number): Port to bind to. defaults to 8080
  • access_log_format (string): Customize access log format for aiohttp. defaults to None
  • store_json (boolean): Serialize object into json field in database. defaults to false
  • host (string): Where to host the server. defaults to "0.0.0.0"
  • port (number): Port to bind to. defaults to 8080
  • conflict_retry_attempts (number): Number of times to retry database conflict errors. defaults to 3
  • cloud_storage (string): Dotted path to cloud storage field type. defaults to "guillotina.interfaces.IDBFileField"

Transaction strategy

Guillotina provides a few different modes to operate in to customize the level of performance versus consistency. The setting used for this is transaction_strategy which defaults to resolve.

Even though we have different transaction strategies that provide different voting algorithms to decide if it’s a safe write, all write operations STILL make sure that the object committed matches the transaction it was retrieved with. If not, a conflict error is detected and the request is retried. So even if you choose the transaction strategy with no database transactions, there is still a level of consistency so that you know you will only modify an object that is consistent with the one retrieved from the database.

Example configuration:

databases:
  - db:
      storage: postgresql
      transaction_strategy: resolve
      dsn:
        scheme: postgres
        dbname: guillotina
        user: postgres
        host: localhost
        password: ''
        port: 5432

Available options:

  • none: No db transaction, no conflict resolution. Fastest but most dangerous mode. Use for importing data or if you need high performance and do not have multiple writers.
  • tidonly: The same as none with no database transaction; however, we still use the database to issue us transaction ids for the data committed. Since no transaction is used, this is potentially just as safe as any of the other strategies just as long as you are not writing to multiple objects at the same time — in those cases, you might be in an inconsistent state on tid conflicts.
  • dbresolve: Use db transaction but do not perform any voting when writing(no conflict resolution).
  • dbresolve_readcommitted: Same as no vote; however, db transaction only started at commit phase. This should provide better performance; however, you’ll need to consider the side affects of this for reading data.
  • simple: Detect concurrent transactions and error if another transaction id is committed to the db ahead of the current transaction id. This is the safest mode to operate in but you might see conflict errors.
  • resolve: Same as simple; however, it allows commits when conflicting transactions are writing to different objects.
  • resolve_readcommitted: Same as resolve however, db transaction only started at commit phase. This should provide better performance; however, you’ll need to consider that side affects of this for reading data.

Warning: not all storages are compatible with all transaction strategies.

Connection class

The default asyncpg connection class has some overhead. Guillotina provides a way to override it with a custom class or a provided lighter one:

pg_connection_class: guillotina.db.storages.pg.LightweightConnection