ConfigMapper

ConfigMapper is meant to be used as a sidecar in a Kubernetes Pod to map local files to ConfigMaps (or Secrets). It can watch files in the local filesystem and when they change, create or update a ConfigMap (or Secret). It can also watch ConfigMaps (or Secrets) with a specific label selector and create or update files in the local filesystem.

Features

• Create or update ConfigMaps or Secrets from local files
  • Watch the local filesystem to keep ConfigMaps and Secrets up-to-date
• Create or update ConfigMaps or Secrets from URLs
  • Poll URLs and store the response in a ConfigMap or Secret
• Extract files from ConfigMaps and Secrets
• Update or delete local files when the ConfigMap or Secret changes
  • Watch ConfigMaps and Secrets to keep local files up-to-date
• Filter based on labels

Configuration

The tool can be configured using a yaml file nameed configmapper.yaml:

# fileMap maps file paths to k8s ConfigMaps or Secrets
fileMap:
  "/tmp/config.yaml":
    type: ConfigMap
    name: my-cm
    namespace: foo
  "/tmp/secrets.yaml":
    type: Secret
    name: my-secret
    namespace: foo

# urlMap maps urls to k8s ConfigMaps or Secrets
urlMap:
  "https://fs.example.com/config":
    type: ConfigMap
    name: my-other-cm
    key: config.json
    namespace: foo
  "https://fs.example.com/secret":
    type: Secret
    name: my-other-secret
    key: secret.json
    namespace: foo

# watcher can watch ConfigMap and Secrets to create files in the Pod's FS
watcher:
  configMaps: true
  secrets: true
  labelSelector: "app=foo"
  namespaces: foo
  defaultPath: "/tmp"

The default path is the local filesystem path where files will be created from the observed ConfigMaps and Secrets, this can be overridden from each ConfigMap (or Secret) through an annotation, you can also use annotations to tell the tool to ignore specific resources or to ignore deletes, to kepp the generated file after the resource was deleted:

metadata:
  annotations:
    configmapper/target-directory: "/path/to/target/directory"
    configmapper/skip: "false"
    configmapper/ignore-delete: "false"

The watcher config can also be set, using environment variables, for example, WATCHER_NAMESPACES can be used to set the list of namespaces to watch. Environment variables are automatically mapped to the comandline flags and named after the config file paths.

Usage

$ configmapper -h
Watch files, ConfigMaps and Secrets.

Usage:
  configmapper [flags]

Flags:
  -c, --config string           config file (default is $HOME/.configmapper.yaml)
  -p, --default-path string     Default path where to write the files (default "/tmp")
  -h, --help                    help for configmapper
  -l, --label-selector string   Label selector for configMaps and secrets
  -n, --namespaces string       Comma separated list of namespaces to watch (defaults to the Pod's namespace)
      --watch-configmaps        Whether to watch ConfigMaps
      --watch-secrets           Whether to watch secrets