Feature : Add Prometheus metrics

[pichouk]

Hi,

I'm currently hosting a Wekan instance for several organisations, and I wonder if we can add a Prometheus endpoint to get some metrics from Wekan, for example :

• number of users
• number of connected users
• number of boards (public or private)

Prometheus is really the leading monitoring solution, and a lot of online softwares have integrated Prometheus exporter (or plugins that does the job).
I guess it should not be too complicated as it consists of exposing a simple plain text file under /metrics, as described in Prometheus documentation. This page is generated regularly based on database query.

I'm not a Javascript developer (nor a developer actually), but I may try to implement an opt-in Prometheus exporter feature if it sounds interesting for other people. Or at least help to describe/design the feature.

[mfilser]

I think the best to integrate third party apps is using the Wekan API.

[xet7]

Yes. For those counts, you would add REST API code to wekan/models/*.js so that admin user (that has logged in to rest api and has valid bearer token) is aithorized to get that info. Then you would call that api in cron script that would write that textfile.

[xet7]

Related https://github.com/wekan/wekan-scheduler

[xet7]

Related #1308

[pichouk]

Yes, maybe I can directly use the API. But I would like some advices because it would be nice to have an API endpoint to get all private boards.

Right now, /api/boards return only public boards, and to get private boards I have to loop on /api/users/{user}/boards for each user (which is really inefficient for a large instance). IMHO it seems logical that /api/boards returns all boards, with an attribute that indicate if a board is private or not.
But it would be a breaking change, so I don't think it will be merged if I submit a PR. Should we had another endpoint ? /api/privateboard ? Or add a GET parameter to /api/boards to choose public or private boards ?

[xet7]

@pichouk

You should add new API endpoint that does .count query/queries and returns number. Not loop through everything with cursor.

[pichouk]

🤔 I'm not sure to understand. You mean I should create a /api/boards_count endpoint that return the number of public/private boards ?

[xet7]

@pichouk

Yes. Somewhere here:
https://github.com/wekan/wekan/blob/master/models/boards.js#L1710

With this kind of MongoDB database counting query:

const privateBoardsCount = Boards.find({ 'permission': 'private' }).count()
const publicBoardsCount = Boards.find({ 'permission': 'public' }).count()

[pichouk]

Ok I see, thanks I'll take a look and submit a PR !

[xet7]

@pichouk

You can build Wekan, test code changes, and send pull request like similar like here:
https://github.com/wekan/wekan/wiki/Emoji#how-you-could-add-another-plugin

But with only your code changes, no need to add any plugin.

[xet7]

Fixed at #3556

[Emile840]

Hi,

@pichouk, did you find a way to implement that prometheus exporter ?
@xet7, do you mind (or do you thing is a good idea) if i implement a new end point in WeKan "/metrics" that will be exposed without authentication and return severals metrics on promotheus text format ?

[xet7]

@Emile840

Wow, without authentication? Those that mass scan Internet would get a lot of details. I prefer no.

[xet7]

WeKan already has Matomo Web Analytics integration, is that not enough?
https://github.com/wekan/wekan-snap/wiki/Supported-settings-keys#matomo-web-analytics-integration

[Emile840]

@xet7,
You're right about authentication issue.
unfortunately, Matomo web will not be enough, how about below solution for working around this authentication issue?

• Adding a possibility for wekan admin user to set (in admin panel ) a list of ip adress that will be authorized when calling "/metrics" end point
• When "/metrics" is called, before performing any action, check first if calling adress was been setted by wekan user

[xet7]

@Emile840

Yes allowed IP address list for metrics is OK.

[pichouk]

Just FYI I made a little python script to act as a Prometheus exporter, which use the Wekan API. it is hosted here but IIRC this is a private Gitlab instance. If you need it I may provide you a gist.

[xet7]

@pichouk

Please provide gist. Thanks!

[pichouk]

You can find a copy of the code here https://gist.github.com/pichouk/2040c30127bec7a561d31d646c4571a7

I'm not sure it will be very helpful because this is just a simple Python script running (in Docker) on the same server than the Wekan instance. This is not great software 😂
Also, please note that I'm not on the entity that run this script anymore, so I am not really able to debug it.

[xet7]

@pichouk

It's very helpful. There are many Python scripts for WeKan already, this is great addition. Thanks!

[xet7]

@pichouk

I added wiki page about what Python code there is for WeKan:
https://github.com/wekan/wekan/wiki/Python

[Emile840]

@xet7
regarding allowed IP address list for metrics, would you mind if a list of trusted ip adress is setted by using an environment variable instead of changing admin panel and corresponded back-end ?

[xet7]

@Emile840

Environment variable usually is less code to add, it's OK.