Create configmap from existing file

[mhubig]

Hi there,

is there a way to use ytt to create a config map from an existing file, e.g. like so:

configmap.yaml

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: renovate-config
  namespace: renovate
  annotations:
    kapp.k14s.io/versioned: ""
    kapp.k14s.io/num-versions: "10"
data:
  config.js: <✨magically import config.js here ✨>

config.js

module.exports = {
      platform: "gitlab",
}

[StevenLocke]

Hi! 👋

From what I gather, you're looking for a way to import a JS file into a YAML file.

There's a (probably not what you want) way of simply importing the file as a string, which can be done with the data.read function.

#@ load("@ytt:data", "data")

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: renovate-config
  namespace: renovate
  annotations:
    kapp.k14s.io/versioned: ""
    kapp.k14s.io/num-versions: "10"
data:
  config.js: #@ data.read("config.js")

Resulting in:

apiVersion: v1
kind: ConfigMap
metadata:
  name: renovate-config
  namespace: renovate
  annotations:
    kapp.k14s.io/versioned: ""
    kapp.k14s.io/num-versions: "10"
data:
  config.js: |-
    module.exports = {
          platform: "gitlab",
    }

---

What I think is more likely though, you're asking how to get the values of that JS object into the YAML map. To do that, you'll need to export the object as JSON (with JSON.stringify), then ytt can decode it with json.decode and use it as expected.

#@ load("@ytt:data", "data")
#@ load("@ytt:json", "json")

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: renovate-config
  namespace: renovate
  annotations:
    kapp.k14s.io/versioned: ""
    kapp.k14s.io/num-versions: "10"
data:
  config.js: #@ json.decode(data.read("config.json"))["exports"]

config.json

{"exports":{"platform":"gitlab"}}

which results in:

apiVersion: v1
kind: ConfigMap
metadata:
  name: renovate-config
  namespace: renovate
  annotations:
    kapp.k14s.io/versioned: ""
    kapp.k14s.io/num-versions: "10"
data:
  config.js:
    platform: gitlab

[mhubig]

The first example is actually what I was looking for, thanks a ton!