RASA Model Rotator

It watches for RASA model directory changes, copies the latest model with a specific name, and deletes the rest of the models.

Why tho?

I was using the RASA Train a Model API and decided to put this script together for the following reasons: First of all at the time of writing this script the RASA train the model API doesn't replace the latest model automatically and to replace it the RASA Replace a Model API needed to be called which requires the model path which would be a randomly generated name after running the trainings. And second the models directory persisting the previous models thus it keep growing and occupies a lot of space.

Usage

With Kubernetes:

Create a shared volume for models and mount it to both RASA-OS and model rotator containers. Make sure volume access mode is set to ReadWriteMany, so both containers able to do required operations. Then deploy the Pods like following example:

# models.pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: models-pvc
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 100M

# rasa.pod.yaml
apiVersion: v1
kind: Pod
metadata:
  name: rasa
spec:
  containers:
  - image: rasa/rasa:latest
    volumeMounts:
      - mountPath: /app/models
        name: models
  securityContext:
    fsGroup: 2000 # Allows processes to write to mounted volumes.
  volumes:
    - name: models
      persistentVolumeClaim:
        claimName: models-pvc

# rasa-log-rotator.pod.yaml
apiVersion: v1
kind: Pod
metadata:
  name: rasa-log-rotator
spec:
  containers:
  - image: tajpouria/rasa-model-rotator:latest
    volumeMounts:
      - mountPath: /app/models
        name: models
  securityContext:
    fsGroup: 2000 # Allows processes to write to mounted volumes.
  volumes:
    - name: models
      persistentVolumeClaim:
        claimName: models-pvc

Environment Variables

• TARGET_DIR: Model directory to watch for changes. default: "models".
• LATEST_MODEL_PATH: Where to copy the latest trained model. default: "models/latest.tar.gz".
• THROTTLE_DELAY: How many milliseconds to wait before copying the latest model. It's needed because Rasa writes the model gradually. default "5000".
• IGNORE_FILE_PATHS: A list of comma-separated extra file paths that must be ignored for deletion.
• LATEST_MODEL_PATH will be ignored all the time. default: "models/lost+found".