Integrating Local File Access into a Knative Function on a Local Kubernetes Cluster

Question

I have a Python code deployed as Knative-functions in which I would like to read a file saved in the local machine under the path '/app/uploads/file.csv'. The Knative cluster is deployed localy using Kind. I would like to have read access of all the files inside '/app/uploads' folder.

What I have so far is:

1. python code that attemps to read the file

    # (...)
    df = csv.read_csv("/app/uploads/file.csv")
    # (...)

2. func.yaml

    specVersion: 0.35.0
    name: func-demo
    runtime: python
    registry: docker.io/<user>
    image: docker.io/<user>/func-demo:latest
    imageDigest: sha256:aa0b6e014726916253b2b37b83044a8d2b94b362b1087dcb189e2465e13663c6
    created: 2023-05-09T13:08:08.390261821+01:00
    build:
      buildpacks: []
      builder: pack
      buildEnvs: []
    run:
      volumes: []
      envs: []
    deploy:
      namespace: default
      remote: false
      annotations: {}
      options: {}
      labels: []
      healthEndpoints:
        liveness: /health/liveness
        readiness: /health/readiness

After deploying the python function to the knative local cluster and invoking it I get this error:

Function raised [Errno 2] No such file or directory: '/app/uploads/file.csv'

---

I also tried definning PersistentVolume and PersistentVolumeClaim in my cluster:

pv.yaml

apiVersion: v1
kind: PersistentVolume
metadata:
  name: uploads
  labels:
    type: local
spec:
  storageClassName: standard
  accessModes:
    - ReadWriteOnce
  capacity:
    storage: 1Gi
  hostPath:
    path: "/app/uploads"

pvc.yaml

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: uploads-claim
spec:
  accessModes:
    - ReadWriteOnce
  storageClassName: standard
  resources:
    requests:
      storage: 1Gi

and defined the previous func.yaml as:

(...)
run:
  volumes:
    - persistentVolumeClaim:
        claimName: uploads-claim
      path: /app/uploads
(...)

but when I deploy the function I get this error:

Error: 'func.yaml' contains errors:
        volume entry #0 is missing secret or configMap field, only path '/app/uploads' is set

Answer 1

You need to define mounts and volumes

https://kind.sigs.k8s.io/docs/user/configuration/#extra-mounts