Simple webserver for externalizing RASA models.

About

You can configure RASA to fetch models from this server either by:

1. pointing to a specific model (.tar.gz) and overriding said file when you want the model to change
   http://localhost:8080/bot/model.tar.gz
2. pointing to a folder (suffixing the url with @latest) containing multiple models (.tar.gz) and getting the latest model sorted by modified date
   http://localhost:8080/bot@latest

Quick start

I recommend pulling the latest image from Docker hub as this is the easiest way:

$ docker pull vrachieru/rasa-model-server

If you'd like, you can build the Docker image yourself:

docker build -t <yourname>/rasa-model-server .

Specify your desired configuration and run the container:

$ docker run -<d|i> --rm \
    -v /host/path/to/models:/app/models \
    -p <host_port>:8080 \
    vrachieru/rasa-model-server

You can stop the container using:

$ docker stop rasa-model-server

Configuration

You can configure the service via the following environment variables.

Environment Variable	Default Value	Description
PORT	8080	Port on which to run the webserver.
MODELS_DIR	models	The absolute or relative location of the models folder.

Example

Fetch a model without specifying a If-None-Match header.

$ curl -s -I 'http://localhost:8080/bot/model.tar.gz'
HTTP/1.0 200 OK
Content-Disposition: attachment; filename=model.tar.gz
Content-Length: 6478848
Content-Type: application/x-tar
Last-Modified: Tue, 23 Apr 2019 12:28:43 GMT
Cache-Control: public, max-age=43200
Expires: Fri, 26 Jul 2019 23:42:05 GMT
ETag: "1556022523.364716-6478848-1948524791"
Date: Fri, 26 Jul 2019 11:42:05 GMT
Accept-Ranges: bytes
Server: Werkzeug/0.14.1 Python/3.6.3

Once the model is loaded by RASA, subsequent requests will use the received ETAG to check if the model has been updated.

$ curl -s -I 'http://localhost:8080/bot/model.tar.gz' -H 'If-None-Match: 1556022523.364716-6478848-1948524791'
HTTP/1.0 304 NOT MODIFIED
Content-Disposition: attachment; filename=model.tar.gz
Cache-Control: public, max-age=43200
Expires: Fri, 26 Jul 2019 23:42:48 GMT
ETag: "1556022523.364716-6478848-1948524791"
Date: Fri, 26 Jul 2019 11:42:48 GMT
Accept-Ranges: bytes
Server: Werkzeug/0.14.1 Python/3.6.3

Update the model on the server an the next request will pull the new model upon ETag mismatch.

$ curl -s -I 'http://localhost:8080/bot/model.tar.gz' -H 'If-None-Match: 1556022523.364716-6478848-1948524791'
HTTP/1.0 200 OK
Content-Disposition: attachment; filename=model.tar.gz
Content-Length: 900
Content-Type: application/x-tar
Last-Modified: Sat, 29 Dec 2018 23:17:54 GMT
Cache-Control: public, max-age=43200
Expires: Fri, 26 Jul 2019 23:43:32 GMT
ETag: "1546125474.453404-900-1948524791"
Date: Fri, 26 Jul 2019 11:43:32 GMT
Accept-Ranges: bytes
Server: Werkzeug/0.14.1 Python/3.6.3

License

MIT