无法通过Kustomize将ConfigMap注入Deployment的问题排查

我正在学习Kubernetes（K8s）基础知识，尝试用Kustomize将ConfigMap注入Deployment，但书中示例无法正常运行。执行kubectl kustomize .后，生成的YAML里没有把ConfigMap/env注入到Deployment中，以下是我的文件内容和命令输出，请问哪里操作错了？

kustomization.yaml #

configMapGenerator:
  - name: outputmap
    files:
      - myconfig1.yaml
resources:
  - nginxdeployment.yaml

myconfig1.yaml #

apiVersion: v1
kind: ConfigMap
metadata:
  name: examplemap
data: |
  key1: value1
  key2: value2

nginxdeployment.yaml #

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginxexercise
spec:
  replicas: 2
  selector:
    matchLabels:
      appKey: nginxValue
  template:
    metadata:
      labels:
        appKey: nginxValue
    spec:
      containers:
        - image: "nginx:1.21.1"
          name: mynginx
          ports:
            - name: myport
              containerPort: 80

kubectl kustomize . 命令输出 #

apiVersion: v1
data:
  myconfig1.yaml: |
    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: examplemap
    data: |
      key1: value1
      key2: value2
kind: ConfigMap
metadata:
  name: outputmap-dc4gdb5cg2
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginxexercise
spec:
  replicas: 2
  selector:
    matchLabels:
      appKey: nginxValue
  template:
    metadata:
      labels:
        appKey: nginxValue
    spec:
      containers:
      - image: nginx:1.21.1
        name: mynginx
        ports:
        - containerPort: 80
          name: myport

问题原因及解决方法 #

你的操作存在两个核心问题：

1. ConfigMapGenerator的使用方式错误 #

你当前通过files字段将整个myconfig1.yaml文件内容作为单个键值对存入了ConfigMap，这完全不是注入Deployment所需的键值对数据结构。

修正方式二选一：

• 方法一：修改myconfig1.yaml为纯键值对格式（移除ConfigMap的API定义）：

key1: value1
key2: value2

• 方法二：在kustomization.yaml中改用literals字段直接定义键值：

configMapGenerator:
  - name: outputmap
    literals:
      - key1=value1
      - key2=value2

2. 缺少ConfigMap与Deployment的关联配置 #

Kustomize不会自动将ConfigMap注入Deployment，必须显式配置关联关系，可通过两种方式实现：

方式一：用Kustomize的patches字段修改Deployment

在kustomization.yaml中添加补丁，将ConfigMap作为环境变量注入容器：

configMapGenerator:
  - name: outputmap
    literals:
      - key1=value1
      - key2=value2
resources:
  - nginxdeployment.yaml
patches:
  - target:
      kind: Deployment
      name: nginxexercise
    patch: |-
      - op: add
        path: /spec/template/spec/containers/0/envFrom
        value:
          - configMapRef:
              name: outputmap

方式二：直接修改Deployment配置

在nginxdeployment.yaml的容器部分添加envFrom字段，引用ConfigMap：

containers:
  - image: "nginx:1.21.1"
    name: mynginx
    ports:
      - name: myport
        containerPort: 80
    envFrom:
      - configMapRef:
          name: outputmap

注意：使用ConfigMapGenerator时，生成的ConfigMap会自动添加哈希后缀（如outputmap-dc4gdb5cg2），Kustomize会自动替换Deployment中的引用，无需手动修改名称。

内容的提问来源于stack exchange，提问作者curiousengineer