OPA(Rego)作为Go库:如何应用外部数据?

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英文:

OPA (Rego) as Go lib: How to apply external data?

问题

我按照https://www.openpolicyagent.org/docs/latest/#5-try-opa-as-a-go-library的示例进行了操作。重要的代码片段:

r := rego.New(
rego.Query("x = data.example.allow"),
rego.Load([]string{"./example.rego"}, nil)
...
rs, err := query.Eval(ctx, rego.EvalInput(input))
...

我该如何添加外部数据(data.json),以便在rego策略中使用,例如data.wantedName来访问它?

我尝试阅读go文档和示例,但没有找到有用的信息。

谢谢!

英文:

I followed the example of https://www.openpolicyagent.org/docs/latest/#5-try-opa-as-a-go-library. Important code snippets:

r := rego.New(
rego.Query("x = data.example.allow"),
rego.Load([]string{"./example.rego"}, nil)
...
rs, err := query.Eval(ctx, rego.EvalInput(input))
...

How can I add external data (data.json) such that I can use, e.g., data.wantedName in the rego policy to access it?

I tried to read through the go doc and the examples but I couldn't find any helpful information.

Thanks!

答案1

得分: 6

你看过rego.Store()的文档和这个示例吗?

对于简单的情况,可以按照以下方式进行操作:

	data := `{
        "example": {
            "users": [
                {
                    "name": "alice",
                    "likes": ["dogs", "clouds"]
                },
                {
                    "name": "bob",
                    "likes": ["pizza", "cats"]
                }
            ]
        }
    }`

	var json map[string]interface{}

	err := util.UnmarshalJSON([]byte(data), &json)
	if err != nil {
		// 处理错误。
	}

	store := inmem.NewFromObject(json)

	// 创建返回值的新查询
	rego := rego.New(
		rego.Query("data.example.users[0].likes"),
		rego.Store(store))

如果需要更复杂的用法,你可以自己实现存储方式,但这将会更加复杂。如果可以通过将inmem.NewFromObject()存储传递给rego.New()来解决问题,建议首先尝试这种方法。

英文:

Have you seen the docs on rego.Store() and this example?

Something along these lines should do the trick for simple cases:

	data := `{
        "example": {
            "users": [
                {
                    "name": "alice",
                    "likes": ["dogs", "clouds"]
                },
                {
                    "name": "bob",
                    "likes": ["pizza", "cats"]
                }
            ]
        }
    }`

	var json map[string]interface{}

	err := util.UnmarshalJSON([]byte(data), &json)
	if err != nil {
		// Handle error.
	}

	store := inmem.NewFromObject(json)

	// Create new query that returns the value
	rego := rego.New(
		rego.Query("data.example.users[0].likes"),
		rego.Store(store))

You could implement your own storage for more intricate uses, but that's going to be a lot more involved. If you get by with feeding inmem.NewFromObject() stores into rego.New(), you should try that first.

huangapple
  • 本文由 发表于 2021年10月8日 15:18:12
  • 转载请务必保留本文链接:https://go.coder-hub.com/69491963.html
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