1. values.schema.json

values.schema.json 文件是对 helm chart values.yaml 文件的一种格式约束，保障了 values.yaml 的字段和值符合严格的约束条件。

1.1. 如 wordpress 的 values.schema.json

$ cat values.schema.json 
{
  "$schema": "http://json-schema.org/schema#",
  "type": "object",
  "properties": {
    "wordpressUsername": {
      "type": "string",
      "title": "Username",
      "form": true
    },
    "wordpressPassword": {
      "type": "string",
      "title": "Password",
      "form": true,
      "description": "Defaults to a random 10-character alphanumeric string if not set"
    },
    "wordpressEmail": {
      "type": "string",
      "title": "Admin email",
      "form": true
    },
    "wordpressBlogName": {
      "type": "string",
      "title": "Blog Name",
      "form": true
    },
    "persistence": {
      "type": "object",
      "properties": {
        "size": {
          "type": "string",
          "title": "Persistent Volume Size",
          "form": true,
          "render": "slider",
          "sliderMin": 1,
          "sliderMax": 100,
          "sliderUnit": "Gi"
        }
      }
    },
    "mariadb": {
      "type": "object",
      "title": "MariaDB Details",
      "form": true,
      "properties": {
        "enabled": {
          "type": "boolean",
          "title": "Use a new MariaDB database hosted in the cluster",
          "form": true,
          "description": "Whether to deploy a mariadb server to satisfy the applications database requirements. To use an external database switch this off and configure the external database details"
        },
        "primary": {
          "type": "object",
          "properties": {
            "persistence": {
              "type": "object",
              "properties": {
                "size": {
                  "type": "string",
                  "title": "Volume Size",
                  "form": true,
                  "hidden": {
                    "value": false,
                    "path": "mariadb/enabled"
                  },
                  "render": "slider",
                  "sliderMin": 1,
                  "sliderMax": 100,
                  "sliderUnit": "Gi"
                }
              }
            }
          }
        }
      }
    },
    "externalDatabase": {
      "type": "object",
      "title": "External Database Details",
      "description": "If MariaDB is disabled. Use this section to specify the external database details",
      "form": true,
      "properties": {
        "host": {
          "type": "string",
          "form": true,
          "title": "Database Host",
          "hidden": "mariadb/enabled"
        },
        "user": {
          "type": "string",
          "form": true,
          "title": "Database Username",
          "hidden": "mariadb/enabled"
        },
        "password": {
          "type": "string",
          "form": true,
          "title": "Database Password",
          "hidden": "mariadb/enabled"
        },
        "database": {
          "type": "string",
          "form": true,
          "title": "Database Name",
          "hidden": "mariadb/enabled"
        },
        "port": {
          "type": "integer",
          "form": true,
          "title": "Database Port",
          "hidden": "mariadb/enabled"
        }
      }
    },
    "ingress": {
      "type": "object",
      "form": true,
      "title": "Ingress Configuration",
      "properties": {
        "enabled": {
          "type": "boolean",
          "form": true,
          "title": "Use a custom hostname",
          "description": "Enable the ingress resource that allows you to access the WordPress installation."
        },
        "hostname": {
          "type": "string",
          "form": true,
          "title": "Hostname",
          "hidden": {
            "value": false,
            "path": "ingress/enabled"
          }
        },
        "tls": {
          "type": "boolean",
          "form": true,
          "title": "Create a TLS secret",
          "hidden": {
            "value": false,
            "path": "ingress/enabled"
          }
        }
      }
    },
    "service": {
      "type": "object",
      "form": true,
      "title": "Service Configuration",
      "properties": {
        "type": {
          "type": "string",
          "form": true,
          "title": "Service Type",
          "description": "Allowed values: \"ClusterIP\", \"NodePort\" and \"LoadBalancer\"" 
        }
      }
    },
    "resources": {
      "type": "object",
      "title": "Required Resources",
      "description": "Configure resource requests",
      "form": true,
      "properties": {
        "requests": {
          "type": "object",
          "properties": {
            "memory": {
              "type": "string",
              "form": true,
              "render": "slider",
              "title": "Memory Request",
              "sliderMin": 10,
              "sliderMax": 2048,
              "sliderUnit": "Mi"
            },
            "cpu": {
              "type": "string",
              "form": true,
              "render": "slider",
              "title": "CPU Request",
              "sliderMin": 10,
              "sliderMax": 2000,
              "sliderUnit": "m"
            }
          }
        }
      }
    },
    "volumePermissions": {
      "type": "object",
      "properties": {
        "enabled": {
          "type": "boolean",
          "form": true,
          "title": "Enable Init Containers",
          "description": "Use an init container to set required folder permissions on the data volume before mounting it in the final destination"
        }
      }
    },
    "metrics": {
      "type": "object",
      "properties": {
        "enabled": {
          "type": "boolean",
          "title": "Enable Metrics",
          "description": "Prometheus Exporter / Metrics",
          "form": true
        }
      }
    }
  }
}