kustomize入门示例及基本语法使用说明

拼搏现实的明天。 2023-09-28 19:18 108阅读 0赞

本文对kustomize进行学习，参见文档[GitHub][]， [Document][]。

`kustomize`lets you customize raw, template-free YAML files for multiple purposes, leaving the original YAML untouched and usable as is.

在[v1.14][]之后，the kustomize build system被合到kubectl中。安装kustomize请参见[Install][]。

一般使用base+overlays的方式来管理yaml文件，base中包含resource yaml文件以及自己的kustomization.yaml文件，overlays中包含base的变种，用来对base中的yaml文件进行修改，适应于不同的环境。

![84a37b04c2ad403832d3e8ec431fe269.jpeg][]

![2c05ddbf60897feb4e2ac79d170aed2b.jpeg][]

通常的文件结构如下：

~/someApp
    ├── base
    │   ├── deployment.yaml
    │   ├── kustomization.yaml
    │   └── service.yaml
    └── overlays
        ├── development
        │   ├── cpu_count.yaml
        │   ├── kustomization.yaml
        │   └── replica_count.yaml
        └── production
            ├── cpu_count.yaml
            ├── kustomization.yaml
            └── replica_count.yaml

使用下面命令来生成YAML文件，也可以直接apply生成的YAML文件。

kustomize build ~/someApp/overlays/production
    kustomize build ~/someApp/overlays/production | kubectl apply -f -

下面来讲解具体使用Kustomization.yaml来定制化k8s yaml文件。

Kustomization.yaml中通常包含3种类型的标注：

*  **Generator** 用来为Kustomize提供Resource Config，像：[bases][], [resources][], [configMapGenerator][], [secretGenerator][];
 *  **Transformers** 用来修改Resource Config， 包括：[images][]， [namespace][]， [namePrefix][]， [nameSuffix][]， [vars][]， [commonAnnotations][]， [commonLabels][]， [patchesJson6902][]， [patchesStrategicMerge][]；
 *  **Meta** 用来配置Generator和Transformers的行为，包括：[configurations][]， [generatorOptions][]。

**-bases:**

bases用来提供一系列包含kustomization.yaml文件的目录或git repo。

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    bases:
    - path/to/dir/with/kust/
    - https://github.com/org/repo/dir/

**-resources：**

用来指定一系列需要配置的Resource Config file，每个文件中可定义多个resource config并使用"\\n---\\n"来分隔。

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    # list of files containing Resource Config to add
    resources:
    - path/to/resource.yaml
    - another/path/to/resource.yaml

**-configMapGenerator：**

包含一系列需要生成的ConfigMaps。默认情况下，会将configmap的hash作为name的后缀，放在nameSuffix之后。

ConfigMap data的更改将会创建具有新name的ConfigMap，并滚动更新正在被使用的ConfigMap。PodTemplates中使用ConfigMap需要使用configMapGenerator的name，这样configmap name更新后会自动更新refer的configmap name。

通过指定generatorOptions.disableNameSuffixHash=true并将该kustomization.yaml作为base，将使得生成的configmap中不包含hash后缀。但这样就不会有滚动升级来实时更新configmap。

包含如下的参数：

*  behavior：定义在base中时指定merge行为，包括：create, replace, merge。
 *  env：指定生成configmap的文件，文件内容以key=value指定；
 *  files: 指定用来生成configmap的多个文件，文件名作为configmap key，文件内容作为value；
 *  literals：使用key=value对来生成configmap；
 *  name：configmap的名称，会被nameprefix和namesuffix修改；
 *  namespace：指定configmap的namespace，会被kustomize的namespace修改。

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    configMapGenerator:
    # generate a ConfigMap named my-java-server-props-<some-hash> where each file
    # in the list appears as a data entry (keyed by base filename).
    - name: my-java-server-props
      files:
      - application.properties
      - more.properties
    # generate a ConfigMap named my-java-server-env-vars-<some-hash> where each literal
    # in the list appears as a data entry (keyed by literal key).
    - name: my-java-server-env-vars
      literals:    
      - JAVA_HOME=/opt/java/jdk
      - JAVA_TOOL_OPTIONS=-agentlib:hprof
    # generate a ConfigMap named my-system-env-<some-hash> where each key/value pair in the
    # env.txt appears as a data entry (separated by \n).
    - name: my-system-env
      env: env.txt

**-secretGenerator**

用来生成Secrets。跟configMapGenerator类似，secretGenerator的name后也会有hash值并在hash值变化时创建新的secret进行滚动升级,同样，可以取消。

具有configMapGenerator中所有的参数并且意义相同。同时，存在参数type来指定Secret的类型，若为"[http://kubernetes.io/tls][http_kubernetes.io_tls]"，需要包含2个key:"tls.key" and "tls.crt".

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    secretGenerator:
      # generate a tls Secret
    - name: app-tls
      files:
        - secret/tls.cert
        - secret/tls.key
      type: "kubernetes.io/tls"
    - name: env_file_secret
      # env is a path to a file to read lines of key=val
      # you can only specify one env file per secret.
      env: env.txt
      type: Opaque

**-commonAnnotations**

用来为所有resources添加或更新指定annotation。

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    commonAnnotations:
      annotationKey1: "annotationValue2"
      annotationKey2: "annotationValue2"

**-commonLabels**

类似于commonAnnotations，用来为所有resource添加或更新指定label。但不同的是，label也会添加到PodTemplates中的label selector和label字段。

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    commonLabels:
      labelKey1: "labelValue1"
      labelKey2: "labelValue2"

**-images**

用来更新所有匹配image name的\[spec.template.\]spec.containers.image字段中的image name和image tag。

若image名称为name:tag，digest用来替代tag来refer image的另一种方法。具有如下参数：

*  name 用于获取匹配image name的所有image；
 *  newName 用来替换所有匹配image的name；
 *  newTag 用来替换所有匹配image的tag；
 *  digest 用来替换所有匹配image的tag；

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    images:
      - name: postgres
        newName: my-registry/my-postgres
        newTag: v1
      - name: nginx
        newTag: 1.8.0
      - name: my-demo-app
        newName: my-app
      - name: alpine
        digest: sha256:24a0c4b4a4c0eb97a1aabb8e29f18e917d05abfe1b7a7c07857230879ce7d3d3

**-patchesJson6902**

用来根据path指定的json或yaml文件来生成target指定的k8s resource。Target中可以包含group, kind, name, namespace, version等信息，Path中指定patch file的路径。

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    patchesJson6902:
    - target:
        version: v1
        kind: Deployment
        name: my-deployment
      path: add_init_container.yaml
    - target:
        version: v1
        kind: Service
        name: my-service
      path: add_service_annotation.yaml

其中，path字段指定的JSON patch文件，格式参见[JSON patch][]。示例如下：

- op: add
       path: /some/new/path
       value: value
     - op: replace
       path: /some/existing/path
       value: new value

**-patchesStrategicMerge**

为匹配的resource config实施patches。推荐使用只修改单个资源的小patch。

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    patchesStrategicMerge:
    - service_port_8888.yaml
    - deployment_increase_replicas.yaml
    - deployment_increase_memory.yaml

**-namespace**

用来指定所有resource的namespace，会覆盖resource中已经指定的namespace。

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    namespace: "my-app-namespace"

\-**namePrefix/nameSuffix**

用来为所有resource name指定前缀或后缀。

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    namePrefix: "my-app-name-prefix-"
    nameSuffix: "-my-app-name-suffix"

**-vars**

用来定义Pod container中的参数或环境变量，使用$(MY\_VAR\_NAME)来使用变量。

包含如下参数：

*  **name** 变量的名称，以$\{name\}方式使用
 *  **objref** Reference to the object containing the field to be referenced.
 *  **fieldref** Reference to the field in the object， 默认为metadata.name

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    vars:
      - name: SOME_SECRET_NAME
        objref:
          kind: Secret
          name: my-secret
          apiVersion: v1
      - name: MY_SERVICE_NAME
        objref:
          kind: Service
          name: my-service
          apiVersion: v1
        fieldref:
          fieldpath: metadata.name
      - name: ANOTHER_DEPLOYMENTS_POD_RESTART_POLICY
        objref:
          kind: Deployment
          name: my-deployment
          apiVersion: apps/v1
        fieldref:
          fieldpath: spec.template.spec.restartPolicy

使用示例：

containers:
    - image: myimage
      command: ["start", "--host", "$(MY_SERVICE_NAME)"]
      env:
       - name: SECRET_TOKEN
         value: $(SOME_SECRET_NAME)

Meta options用来控制Kustomize怎么生成来更新resource config。包含configurations和generatorOptions。

**-configurations**

用来配置built-in Kustomize Transformers指定CRD过程中的行为。

**-generatorOptions**

用来定制化configmap/secret generator的行为。

示例：

apiVersion: kustomize.config.k8s.io/v1beta1
    kind: Kustomization
    generatorOptions:
      # labels to add to all generated resources
      labels:
        kustomize.generated.resources: somevalue
      # annotations to add to all generated resources
      annotations:
        kustomize.generated.resource: somevalue
      # disableNameSuffixHash is true disables the default behavior of adding a
      # suffix to the names of generated resources that is a hash of
      # the resource contents.
      disableNameSuffixHash: true

样例Kustomization.yaml参见[Kustomization.yaml][]。

--------------------

参考链接：

[kustomize - 知乎本文对kustomize进行学习，参见文档 GitHub， Document。 kustomizelets you customize raw, template-free YAML files for multiple purposes, leaving the original YAML untouched and usable as is.在 v1.14之…![apple-touch-icon-152.a53ae37b.png][]https://zhuanlan.zhihu.com/p/92487688][kustomize - _kustomize_ GitHub_ Document_ kustomizelets you customize raw_ template-free YAML files for multiple purposes_ leaving the original YAML untouched and usable as is._ v1.14_apple-touch-icon-152.a53ae37b.png_https_zhuanlan.zhihu.com_p_92487688]

[GitHub]: https://link.zhihu.com/?target=https%3A//github.com/kubernetes-sigs/kustomize
[Document]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html
[v1.14]: https://link.zhihu.com/?target=https%3A//kubernetes.io/blog/2019/03/25/kubernetes-1-14-release-announcement
[Install]: https://link.zhihu.com/?target=https%3A//github.com/kubernetes-sigs/kustomize/blob/master/docs/INSTALL.md
[84a37b04c2ad403832d3e8ec431fe269.jpeg]: https://img-blog.csdnimg.cn/img_convert/84a37b04c2ad403832d3e8ec431fe269.jpeg
[2c05ddbf60897feb4e2ac79d170aed2b.jpeg]: https://img-blog.csdnimg.cn/img_convert/2c05ddbf60897feb4e2ac79d170aed2b.jpeg
[bases]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23bases
[resources]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23resources
[configMapGenerator]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23configmapgenerator
[secretGenerator]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23secretgenerator
[images]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23images
[namespace]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23namespace
[namePrefix]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23nameprefix
[nameSuffix]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23namesuffix
[vars]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23vars
[commonAnnotations]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23commonannotations
[commonLabels]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23commonlabels
[patchesJson6902]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23patchesjson6902
[patchesStrategicMerge]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23patchesstrategicmerge
[configurations]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23configurations
[generatorOptions]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/reference/kustomize.html%23generatoroptions
[http_kubernetes.io_tls]: https://link.zhihu.com/?target=http%3A//kubernetes.io/tls
[JSON patch]: https://link.zhihu.com/?target=https%3A//tools.ietf.org/html/rfc6902
[Kustomization.yaml]: https://link.zhihu.com/?target=https%3A//kubectl.docs.kubernetes.io/pages/examples/kustomize.html
[apple-touch-icon-152.a53ae37b.png]: https://static.zhihu.com/heifetz/assets/apple-touch-icon-152.a53ae37b.png
[kustomize - _kustomize_ GitHub_ Document_ kustomizelets you customize raw_ template-free YAML files for multiple purposes_ leaving the original YAML untouched and usable as is._ v1.14_apple-touch-icon-152.a53ae37b.png_https_zhuanlan.zhihu.com_p_92487688]: https://zhuanlan.zhihu.com/p/92487688