CrashLog payload structure

Readme.markdown

CrashLog events API

CrashLog accepts events over HTTP to stdin.crashlog.io. Events are authenticated with HMAC (see below) using an api_key and secret. Upon successfully authenticating the payload will be consumed.

HMAC authenticated requests

All payloads must be sent along with a HMAC Authorization header, this should be structured like this:

Authorization: CrashLog <api-token>:<HMAC Signature>

In a nutshell this signature is constructed from the headers you are sending with the payload, example:

hmac_string     = HTTP-Verb    + "\n" +
                  Content-Type + "\n" +
                  Content-MD5  + "\n" +
                  Date         + "\n" +
                  request-uri;

"Authorization: CrashLog " + API-Token + ":"  + base64(hmac-sha1(hmac_string))
"Authorization: Staging " + API-Token + ":"  + base64(hmac-sha1(hmac_string))

The service ID CrashLog is to be used for authenticating against the production App at http://crashlog.io and Staging is used for authenticating and sending events to the staging App.

To see exactly how this is constructed take a look at the source of crashlog-auth-hmac gem and crashlog.

The api_key and secret pair can be found on the settings page of your project. You should never send the secret down the wire and only expose it to your application for obvious security reasons.

If these credentials become compromised you can revoke then within the settings page as well.

Endpoints

CrashLog supports two endpoints, one for announcing application launch or deployment, and one for consuming events.

Announce

Host: stdin.crashlog.io

POST /announce

Announce simply returns the application name so you can check that your application is configured correctly. In the Ruby gem this will write a line to your production log file with the name of the project.

Typically you would send the hostname and a timestamp in this payload and it will be displayed in the project overview page.

Events

Host: stdin.crashlog.io

POST /events

Event payload

You can see the event payload example below, but here are the basics:

The payload can contain multiple interfaces, of which only 2 are required:

• notifier (required)
• event (required)
• backtrace
• environment
• context
• data

Notification response

A successfully lodged exception will return a hash like:

"{"location_id": "<128bit UUID>"}

location_id can be used to generate a URL to link directly to the exception or fetch information about it from the CrashLog public API.

Generating URLs

The standard location for locating exceptions within the CrashLog UI is http://crashlog.io/locate/:location_id

This will either return 404 if the exception has not yet been loaded (< T+1 second) or 301 with a redirection to the actual error page.

payload.json

{
  "payload" : {

    // Interface: Notifier
    "notifier" : {
      "name": "crashlog-nodejs",
      "version": "1.0.0"
    },

    // Interface: Event
    "event" : {
      "message" : "Some one line error description",
      "type": "RuntimeError",
      "timestamp" : "2012-08-03T12:34:19+10:00"
    }

    // Interface: Backtrace
    "backtrace" : [
      {
        // Required
        "file": "somewhere.js",
        "number": 14, // Line number
        "method": "raiseTheRoof",

        // Optional
        "context_line": "source code for affected line",
        "pre_context" : ["line -1 before affected line", "line -2 before affected line", "line ..."],
        "post_context" : ["line +1 after affected line", "line ..."]
      },

      {
        // Required
        "file": "somewhere_else.js",
        "number": 192, // Line number
        "method": "setup",

        // Optional
        "context_line": "source code for affected line",
        "pre_context" : ["line -1 before affected line", "line -2 before affected line", "line ..."],
        "post_context" : ["line +1 after affected line", "line ..."]
      }
    ],

    // Interface: Environment
    // Optional
    //
    // Any key value pairs you want to be able to view later on
    //
    // At the moment this is unstructured, this will likely change in the furure.
    "environment": {
      "project_root" : "/home/deploy/my_app/current",
      "platform" : "Node.js 0.6.x",
      "name": "production",
      "system": {
        "distribution": "Ubuntu 12.04 LTS"
      },
      "browser": {
        "ident": "Usual browser tag"
      },

      "plugins": []

      // TODO: Insert more attributes here

    },

    // Interface: Context
    // Optional
    // Any contextual information relating to the cause of this error
    // This is typically a serialisation of the current user
    //
    // The attributes can be used to correlate errors
    "context" : {
      "hostname": "app01.myhostname.com",
      "current_user": {
        "id": 1,
        "email": "ivan@crashlog.io"
      },

      "controller": {
        "name": "usersController",
        "action": "index"
      }
    }
  }
}

Just reviewing this again and a couple of things.

• What HTTP method is "sent" in the context of pushing messages to http://stdin.crashlog.io/notify?
• Can i get a test login to try this logger out?

Hi Mark,

All requests use the POST method and should return a 201 response if successful or a corresponding error code like 400,401,403,500 depending on what went wrong. All responses are JSON encoded hashes.

I've updated the HMAC string above, it should work correctly now.