readme.md

Load data into a ConfigMap

CUE input file:

package kube

configMap: [ID=_]: {metadata: name: ID}

configMap: "app-metadata": {
    apiVersion: "v1"
    kind:       "ConfigMap"
    data: {
        version: string @readfile(version.txt=trim)
    } @readmap(meta.yaml)
}

configMap: "scripts": {
    apiVersion: "v1"
    kind:       "ConfigMap"
    data: {} @readmap(scripts)
}

objects: [ for v in configMap {v}]

External data, e.g. buildinfo or scripts can be imported into a ConfigMap.

• @readfile(version.txt=trim) reads the whole file, and, because of the =trim suffix, removes any leading and trailing whitespace
• @readmap(meta.yaml) reads the given YAML file as key/value data (readmap only allows one level) and adds it to the data struct
• @readmap(scripts) reads all files from the scripts directory as key/values into the ConfigMap

Using multiple attributes for the structure data is ok, this does not lead to conflicts, as long as the loaded data itself does not conflict.

YAML output:

apiVersion: v1
kind: ConfigMap
metadata:
  name: app-metadata
data:
  version: v1.0.0
  vcs.modified: "false"
  vcs.revision: 54f9ca
  vcs.time: "2023-01-10T12:00:00Z"
  vcs: git
  CGO_ENABLED: "0"
  go: go1.20
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: scripts
data:
  start.sh: |
    #!/bin/bash
    echo "starting demo-app..."
  stop.sh: |
    #!/bin/bash
    echo "stopping demo-app..."