Monitor Conditions

[simshaun]

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Description

Hello,

We have a need at work for monitoring values of DNS records. I got (really) bored and decided to do something about it. I understand this is a semi-major feature and may need some changes, or maybe you don't like it all. That's fine.

This PR introduces support for setting up conditions that affect UP/DOWN status on monitors. It pertains to #3919 and eventually, I think, could obviate the need for the keyword type, and maybe the JSON Query type.

It is opt-in per type, and I've only opted-in the DNS type for now. So, this doesn't break existing keyword/JSON query types. It's generic but extendable enough in my opinion that it could allow implementing a wide variety of scenarios without needing further UI changes going forward.

Currently missing the ability to drag conditions around, but that shouldn't be too difficult to shoehorn in eventually.

Screenshots below.

Type of change

• User interface (UI)
• New feature (non-breaking change which adds functionality)
• This change requires a documentation update

Checklist

• My code follows the style guidelines of this project
• I ran ESLint and other linters for modified files
• I have performed a self-review of my own code and tested it
• I have commented my code, particularly in hard-to-understand areas (including JSDoc for methods)
• My changes generates no new warnings
• My code needed automated testing. I have added them (this is optional task)

Screenshots (if any)

Groups:

[CommanderStorm]

Looks very nice. Good job.
The testcases are most appreciated ❤️

I have left a few inline comments below. ^^

[CommanderStorm]

Why not the following? (also goes for NotEqualsOperator)
Could you add a comment explaining the reasoning ^^

Suggested change

	// eslint-disable-next-line eqeqeq
	return variable == value;
	return variable === value;

[simshaun]

I initially was going to add an mx_priority variable to check MX record priorities. Node's DNS module parses MX records and returns priority as a number type.

In this new conditions UI, comparison values are stored as strings. i.e. My condition would be stored in the monitor as mx_priority equals "10".

I have a set of numeric operators (less than, greater than, etc) that cast the value to Number internally, but the EqualsOperator is currently used for both strings and numbers. It needs loose equality to handle 10 == "10".

An alternate solution could be to rename this operator to StringEquals (make it strict) and add a new NumberEquals operator (also strict) that casts value internally.

[CommanderStorm]

Adding a comment that this is because of sharing between numbers and strings to handle 10 == "10" is likely fine.

[simshaun]

I'm flip-flopping on this.

I can't currently think of a scenario where the loose equality operators wouldn't get the job done, but I think it may be advantageous to start this feature out with strict operators rather than maybe trying to implement them later on and have to worry about backwards compatibility.

So, a monitor type would need to use the default string or number operators, or explicitly use either StringEquals or NumberEquals when declaring its supported condition variables.

[simshaun]

Since #5056 was merged, I've fixed, added to, and improved the E2E tests for this PR.

I'll go through your remaining comments sometime later today.

[simshaun]

I think I've handled all the remaining issues.

[CommanderStorm]

Thanks for the enhancement! 🎉

Note

This PR is part of the v2.0 merge window => see #4500 for the bugs that need to be addressed before we can ship this release ^^

_{All changes in this PR are small and uncontroversial ⇒ merging with junior maintainer approval}

[vishalsabhaya]

@simshaun @CommanderStorm

i am working on below improvement.
#5025
i want to do final testing so i taken pull from master branch but i am getting below error.

as per my research.
i have putted log for debug

console.log("sdfwfwkjfhwhfkwefjewf");
console.log(this.conditions);
console.log("sdfwfwkjfhwhfkwefjewf");

this.conditions is no value so it is "".
SyntaxError: Unexpected end of JSON input is occurs.

i think blank then we need to pass some default json or null.

[simshaun]

@vishalsabhaya

The migration in this database changes sets a default value of [] for the conditions column in the database. I'm curious how yours is ending up empty.

[vishalsabhaya]

@simshaun

i am using mariadb. is there any problem with MySQL? have you written migration for MySQL?

[simshaun]

@vishalsabhaya The migration should be database agnostic.

https://github.com/louislam/uptime-kuma/pull/5048/files#diff-4111d2d321bfe6baf61dc1b78521a8ee9445bf86f599aac8fa3be00cb85139f1

Can you confirm via DBMS the default value of the conditions column in the monitor table?