Proxy with Behavior

Proxy with Behavior is a node application that work as a reverse proxy, and enables apply some behaviors to be executed in requests.

How to use the API?

The proxy API to handle with behaviors, usually uses port 3001.

How to get it running

To run the proxy using docker, execute the following commands:

docker build -t proxy-with-behavior .

docker run --rm -d -p 3000:3000 -p 3001:3001 -e "NODE_ENV=production" -e "SERVICE_URL=https://jsonplaceholder.typicode.com" --name proxy-with-behavior-container proxy-with-behavior

If you want to apply this proxy, in front of your app, you just need to configure the network (or service) as a proxy. Consider that SERVICE_URL is a environment variable used to determine who is the proxied service.

GET /behaviors

List all stored behaviors

# curl http://localhost:3001/behaviors
{
	"behaviors": [
		{
			"id": 1,
			"type": "change-response",
			"resource": "/posts",
			"method": "POST",
			"status": 500,
			"active": true,
			"data": null,
			"pattern_source":null,
			"pattern_flag":null,
			"createdAt": "2022-01-07T19:58:24.895Z",
			"updatedAt": "2022-01-07T19:58:24.895Z"
		},
		{
			"id": 2,
			"type": "change-response",
			"resource": "/posts",
			"method": "GET",
			"status": 500,
			"active": true,
			"data": null,
			"pattern_source":null,
			"pattern_flag":null,
			"createdAt": "2022-01-07T19:58:29.465Z",
			"updatedAt": "2022-01-07T19:58:29.465Z"
		}
	]
}

POST /behaviors

Store behaviors and return the updated list. It's important to say that you can only associate a single behavior to a resource/method. This means, for instance, if you store a change-response behavior to the method/resource GET /posts, you can't store another behavior to the same method/resource, but if you want it, you can do this to another method of a resource (e.g. latency behavior applied to POST /posts).

# curl -X POST http://localhost:3001/behaviors -d '{"type": "change-response","resource": "/posts","method": "GET","status": 500, "pattern": {"source": "see (chapter \\d+(\\.\\d)*)","flag": "i"} }'
{
	"behaviors": [
		{
			"id": 2,
			"type": "change-response",
			"resource": "/posts",
			"method": "POST",
			"status": 500,
			"active": true,
			"data": null,
			"pattern_source": "see (chapter \\d+(\\.\\d)*)",
			"pattern_flag": "i",
			"createdAt": "2022-01-11T01:33:37.187Z",
			"updatedAt": "2022-01-11T01:33:37.187Z"
		}
	]
}

• Required fields: type, resource, and method
• Not required fields: status, pattern.source, pattern.flag, active and data;

When you try latency behavior, use data field and consider this field as timeout in milliseconds value. This means if you use 'data': '5000', the behavior will apply a latency of 5 seconds before execute the request. pattern.source and pattern.flag are used to define a regular expression that will verify where apply the behavior.

PUT /behaviors/:id/toggle

Toggle behavior's active state.

# curl -X PUT http://localhost:3001/behaviors/1/toggle
{
	"behaviors": [
		{
			"id": 2,
			"type": "change-response",
			"resource": "/posts",
			"method": "POST",
			"status": 500,
			"active": true,
			"data": null,
			"pattern_source": "see (chapter \\d+(\\.\\d)*)",
			"pattern_flag": "i",
			"createdAt": "2022-01-11T01:33:37.187Z",
			"updatedAt": "2022-01-11T01:33:37.187Z"
		}
	]
}

DELETE /behaviors/:id

Deletes a behavior by his ID and returns the updated list.

# curl -X DELETE http://localhost:3001/behaviors/1
{
	"behaviors": []
}

Behavior types

• change-response: Change the response (enables you to change status, or the data returned);
• latency: Add latency to the request;

What it does?

• Proxy requests to a service;
• API to enable behavior's manipulation;
• Register of change-response behavior, enabling intercept and change status code's response;
• Register of latency behavior, enabling add latency in milliseconds;
• It's possible define a regular expression pattern, that will check if a behavior must be applied or not. If none pattern is defined, the behavior will be applied;
• Toggle of active behavior's state;

What's next

• On change-response use data attribute as response when exists;