Implementing Configuration API with ctripcorp/apollo

Objective

Implementation of Configuration API(level-2) with ctripcorp/apollo

Schema

Configuration API map apollo schema

The mapping rules are as follows:

Configuration API Parameters	apollo schema
app_id	///ignore this parameter when searching for or subscribed to it, use app_id in configuration file instead
Group	name
label	//追加到key的后面. 在apollo中key实际存储的格式为'key@$label'
tag	// Put an item in the configuration in json

在apollo中key实际存储的格式为key@$label，value为原始值。

Tags将以key=group@$key@$label and value=

LO
  "tag1": "tag1value",
  "tag2": "tag2value"
}

Format is stored in a specific namespace sidecar_config_tags

Q: Why don't you have an item to store values and tags to reduce the number of queries, e.g. :

{
    "value":"raw value",
    "tags":{
        "tag1":"tag1value",
        "tag2":"tag2value"
    }
}

A: If this design is adopted, the historical legacy of the use of apollo will not be able to migrate to sidecar

How to migrate historical legacy projects

1. Get/subscripbe API is compatible.Without save/delete API, users can easily migrate legacy projects to sidecar.只需要在config.json文件中保持label字段为空，sidecar将会使用原始key来替代key@$label与apollo进行交互。
2. Save/delete API may not be compatible.sidecar uses fixed cluster and env fields in config.json.This means that users cannot use cluster and env fields as parameters for save/deleteAPI if they want to change some configuration items with other appids.

sidecar config.json file

{
  "config_store": {
    "type": "apollo",
    "address": [
      "http://106.54.227.205:8080"
    ],
    "metadata": {
      "app_id": "testApplication_yang",
      "cluster": "dev",
      "namespace_name": "dubbo,product.joe",
      "is_backup_config": true,
      "secret": "6ce3ff7e96a24335a9634fe9abca6d51"
    }
  }
}

API

Which Apollo SDK should I use?

Currently using official maintenanceSDK, other Apollo's third party SDK can be found from链接.

Use some of this sdk's attention:

1. Before connecting to the server and creating the client, the user must declare all namespace in the AppConfig, as shown below in：

	c := &config. ppConfigL
		AppID: "testApplication_yang",
		Cluster: "dev",
		IP: "http://106. 4.227. 05:8080",
		NamespaceName: "dubbo", // Statement
		IsBackupConfig: true,
		Secret: "6ce3ff7e96a24335a9634fe9abca6d51",
	}
	client, err := agolloConfig. tartWithConfig(func() (*config.AppConfig, error) {
		return c, nil
	})

1. You cannot configure the env field.

2. No Save/delete API.

3. No bulk queries for API.

4. Security cannot be ensured in parallel.

5. Configure or don't use Apollo Meta Server.

6. There is a problem setting kv and tags. There is no transaction.

How I should use the Apollo SDK API

Configuration API	apollo sdk API
GetConfiguration	cache := client.GetConfigCache(c.NamespaceName)value,_:= client.Get("key")
SaveConfiguration	通过http. update + commit 使用open API
DeleteConfiguration	使用http. delete + commit 使用open API
SubscripbeConfiguration	https://github.com/apolloconfig/agollo/wiki/%E7%9B%91%E5%90%AC%E5%8F%98%E6%9B%B4%E4%BA%8B%E4%BB%B6

How to subscribe to all configuration changes for the specified app

Subscribe to all declared namespaces in config.json file.