LogDNA Logging on Cloudflare Workers

Beta

Please use care when using in production environments.

Requirements

* Your project needs to have either
* [type = "webpack"] in its wrangler.toml
* or some kind of [build configuration].
* An account with [LogDNA] (there's a free tier).
* An account with [Cloudflare] (there's a free tier).

Install

From your Cloudflare Worker project, run:

``sh
npm install @phistrom/cf-logdna
``

Specify your [LogDNA ingest API key] by adding a secret to your Worker:

`sh
wrangler secret put LOGDNA_KEY

put in your API key from LogDNA here when prompted

`

Specify the [APP_NAME] in one of two ways:

Add the following to your wrangler.toml file as an [environment variable]:

`toml
vars = { WORKER_NAME = "cf-logdna-testing" }
`

Or you can add self.WORKER_NAME to your code directly like this:

`javascript
import "@phistrom/cf-logdna"

self.WORKER_NAME = "myworker"

addEventListener('fetch', event => {
// ...
})
`

How to Use

Just import @phistrom/cf-logdna as early in your code as possible to immediately benefit from the logging of incoming
requests, responses, unhandled errors, and objects/messages logged to the console.

`javascript
// as close to the top as possible of your entry script (i.e. index.js)
import "@phistrom/cf-logdna"

addEventListener('fetch', event => {
// ...
})
`

$3

cf-logdna attempts to associate log lines with the request/response context (event) they came from. Sometimes this
isn't possible (due to the way that [Date.now() works]). **To ensure that every log line can be associated with a
FetchEvent**, cf-logdna provides an event.console
object.

`javascript
import "@phistrom/cf-logdna"

addEventListener('fetch', event => {
console.log("I get logged to LogDNA just fine.")
event.console.log("I'm a better way of doing things, though.")
event.console.error("I'm an error message!")
console.critical("I'm a non-standard critical message! But I may not have the FetchEvent information.")
event.console.critical("critical() behaves the same as console.error, but will log a CRITICAL level entry on LogDNA.")
$console.log("I don't get sent to LogDNA. I act like the vanilla console object.")
throw new Error("I'll see you in wrangler tail AND in your LogDNA viewer!")
})
`

event.console ensures that log lines sent to LogDNA have a meta.eventTimestamp field. Using the regular console
may still provide this field, but only until the first fetch()
call made (the Date.now() clock [only advances after I/O calls]).

_Do not_ assign the event.console object to a global variable. You should pass it into the functions handling the
events. It can be a pain going through and changing all your code to say event.console.log instead of console.log,
but it's not a requirement.

License

MIT

Contributing

I'm not very skilled at Javascript. I'm getting better because Cloudflare Workers is such a great product, but I'm sure
there are optimizations that could be made or bugs to be squished. Pull requests are very welcome and very much
appreciated.


[type = "webpack"]:

[build configuration]:

[LogDNA]:

[Cloudflare]:

[LogDNA ingest API key]:

[APP_NAME]:

[environment variable]:

[Date.now()` works]:

[only advances after I/O calls]: