tekton & buildpack: certificate signed by unknown authority

Question

I've deployed a local docker registry. It uses a self-signed certificate.

When I'm trying to run buildpacks task, I'm getting this message:

x509: certificate signed by unknown authority

I've took a look on documentation, about how to add my docker registry certificate, but I've not been able to set it up.

pipeline.yaml is:

apiVersion: tekton.dev/v1beta1
kind: Pipeline
metadata:
  name: build-and-deploy-pipeline
spec:
  workspaces:
    - name: git-source
      description: The git repo
    - name: dockerconfig-ws
      description: Docker configuration
  params:
    - name: gitUrl
      description: Git repository url
  tasks:
    - name: fetch-repository
      taskRef:
        name: git-clone
      workspaces:
        - name: output
          workspace: git-source
      params:
        - name: url
          value: "$(params.gitUrl)"
        - name: subdirectory
          value: "."
        - name: deleteExisting
          value: "true"
    - name: buildpacks
      taskRef:
        name: buildpacks
      runAfter:
        - fetch-repository
      workspaces:
        - name: source
          workspace: git-source
        - name: dockerconfig
          workspace: dockerconfig-ws
      params:
        - name: APP_IMAGE
          value: host.k3d.internal:5443/restservice
        - name: BUILDER_IMAGE
          value: paketobuildpacks/builder:tiny

And pipelinerun.yaml:

apiVersion: tekton.dev/v1beta1
kind: PipelineRun
metadata:
  generateName: tekton101lab-pipelinerun-
spec:
  pipelineRef:
    name: build-and-deploy-pipeline
  params:
    - name: gitUrl
      value: https://[email protected]/cicdgitops/rest-service.git/
  workspaces:
    - name: git-source
      persistentVolumeClaim:
        claimName: git-pvc
    - name: cache-ws
      persistentVolumeClaim:
        claimName: cache-pvc
    - name: dockerconfig-ws
      secret:
        secretName: dockerconfig-secret

Any ideas?

I mean, how could I add my docker registry certificate as a trusted ca certificate?

You can see behavior here. Problem arises when buildpacks tasks are trying to reach my docker registry (host.k3d.internal).