ReqStatSrv

A dummy server that reports the number of requests made.

Usage:

docker pull dhontecillas/reqstatsrv:v0.2
docker run --rm -p 9876:9876 -v ./example:/etc/reqstatsrv dhontecillas/reqstatsrv:v0.2  /reqstatsrv /etc/config/example.json

or from the base repo run:

make dockerrun

Configuration

The server uses the Go's standard lib router, so, for now it does not have variable path matching (/foo/{something_to_match}/var), or matching by request method (GET, POST, etc..) for now (but a new router implementation is expected to land soon in next version of Go).

The server can be configured by passing a JSON config file as only argument.

At the root level, you can configure:

• port: the binding port
• host: the address to bind to
• endpoints: the list of endpoints to serve

Enpoint

The endpoint has:

• method: currently is not used to match the request, as we are waiting for the new Go router to land in the stdlib.
• path_pattern: a simple "path prefix" to match (no vars, nor wildcards allowed for now).
• behaviour: configuration about how we want the response to behave (see explanation below).
• content: configuration about the content to serve with the request (headers and body are generated at this level).

Behaviours

Delay

Waits for a certain amount of time defined by a distribution of milliseconds ramp.

You define a list of key (milliseconds) / value (probability) pairs. Those are the probability of having a dalay below that "key" milliseconds.

Example:

Key	Val
0	0.05
50	0.20
150	0.0
300	0.25
500	0.5

With the above values, 5% of request will have no delay at all, a 20% will be between 0 and 50 ms of delay, there will be no requests with a dealay between 50 and 150 ms, and then there will be a 25% of requests with a delay between 150 and 300ms, and the rest of requests will have a delay between 300ms and 500ms.

{
    "name": "delayer",
    "config": {
        "delay_millis_distribution": [
            {"key": 0, "val": 0.05},
            {"key": 10, "val": 0.2},
            {"key": 50, "val": 0.0},
            {"key": 100, "val": 0.5},
            {"key": 200, "val": 0.0},
            {"key": 700, "val": 0.25}
        ],
        "seed": 1
    }
}

Slower

Makes any content to be served at a given rate. The flush call can be also tweaked.

{
    "name": "slower",
    "config": {
        "max_bytes_per_second": 100,
        "flush_bytes": 2
    }
},

Status Distributor

The status code to produce is stored in the incoming request context, so, the content providers can read it (and "respect" the choice taken at the behaviour level), and might be able to select the content based on the status code.

Here we define a similar distribution as in the delay part, but with the difference that the produced values will not be interpolated.

Key	Val
200	0.5
201	0.3
204	0.2

So, with that config, we will have 200 in 50% of the requests, 201 in 30% of the requests and a 204 in the rest.

Values are normalized, meaning that we could set the values to 5, 3 and 2 and the result would be the same.

{
    "name": "status_distributor",
    "config": {
        "code_distribution": [
            {"key": 200, "val": 0.5},
            {"key": 201, "val": 0.3},
            {"key": 204, "val": 0.2}
        ],
        "seed": 1
    }
}

Connection Closer

This behaviour will close the connection with the frequency selected: the range for freq must be between 0.0 and 1.0.

{
    "name": "connection_closer",
    "config": {
        "freq": 0.5,
        "seed": 1
    }
}

Content

Empty

Will just set the Content-Length to 0, and return without writing the body.

Dummy

This content is here for testing purposes, and will surely be deleted on the 1.0 version.

Directory

Will just serve the files that are set in the directory path

{
    "source": "directory",
    "config": {
        "dir": "./example/data"
    }
}

File

The response for the endpoint is directly mapped to the given file. The content-type is extracted from the file extension.

{
    "method": "GET",
    "path_pattern": "/file",
    "behaviour": [],
    "content": {
        "source": "file",
        "config": {
            "path": "./example/data/bar.json" 
        }
    }
}

Stats

This content reports basic stats for the served requests.

Currently it only shows "instant" requests count (the number of requests served for each endpoint in the past second).

"content": {
    "source": "stats",
    "config": {}
}