Add a REST API output

[andrewkroh]

Add an "output" that hosts the log messages via a REST API. The format of the returned document could be configurable via a Go text/template

Things that should be configurable:

• path
• content-type
• paging style (timestamp based or http link headers)
• body format template
• tls settings

[marc-gr]

Since this is meant to fake an HTTP Server, it should be able to handle a serie of requests. Maybe having some sort of configuration file to define how to behave and what to return to a particular call could be nice.

I was thinking of something on the lines:

// A list of match rule definitions.
// It will match by the combination of method, path, query, and request_headers.
// If no method is defined, any will match, if no query is defined, any will match, etc.
// They will match in order, so more specific rules must go on top.
[
    {
        "method": "post",
        "path":"/foo/bar", // accepts a regexp
        "query": {}, // accepts a regexp in the values, the values must not be URL encoded.
        "request_headers": {}, // they can accept regexp in the values.
        "response_headers": {},
        "tls": {
            "cert": ""
            // ...
        },
        "body": [ // If more than 1 body is defined, 
                  // they will be returned in serie, first time the rule matches, will return body.0, second, body.1, etc. 
            "{ 
                // Not sure how text/template would work here other that functions, 
                // where would we get the values from? maybe from the request?
            }"
        ] 
    },
    // ...
]

When it comes to pagination, I think with this the users can define how it should behave and fake pagination as needed.