Kustomize configMapGenerator

configMapGenerator creates ConfigMaps from files, literals, or env files and appends a content hash to the name.

Generated ConfigMaps get a hash suffix, so changing the data changes the name and forces a rollout. This is the idiomatic way to ship config with Kustomize.

What it does

configMapGenerator produces a ConfigMap from literals, whole files, or an env file. By default Kustomize appends an 8-character content hash to the name and rewrites every reference to it, so editing the data renames the ConfigMap and triggers a rolling update of the consuming Deployment.

Common usage

kustomization.yaml

configMapGenerator:
  - name: app-config
    literals:
      - LOG_LEVEL=info
      - REGION=us-east-1
    files:
      - config.json
    envs:
      - app.env

Fields

Field	What it does
name	Base name of the ConfigMap
literals	KEY=value pairs as data entries
files	Files whose contents become data (key is the filename)
envs	Env files: each line becomes a data key
behavior	create, replace, or merge with an existing ConfigMap
options.disableNameSuffixHash	Turn off the content hash suffix

In CI

The hash suffix is the feature, not a bug: it guarantees a rollout when config changes. Only disable it (disableNameSuffixHash: true) when an external system references the ConfigMap by a fixed name. Keep env files out of secrets; use secretGenerator for sensitive values.

Common errors in CI

"already registered id" or a hash-mismatch reference means a manifest references the ConfigMap by its base name without the generator rewriting it; reference it through the generated resource, not a hardcoded name. "env file ... not found" means the envs path is wrong. A key with characters outside [-._a-zA-Z0-9] is rejected with "a valid config key must consist of alphanumeric characters".