Add support for custom mongodb commands

[SebastianLng]

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Description

Extends the MongoDB monitor to allow running custom MongoDB commands and optionally comparing the value against an expected value.

Besides being able to check database content, this is useful to further check the health of MongoDB, especially clusters. For example, the hello command offers various health information which can be queried and checked with this change.

From a UI standpoint, this adds a command input, a json query input and an expected value input. All are basically the same as comparable HTTP(s) Json query inputs and other DB monitors inputs.
All new fields are optional, and the default command is still the ping command that was used before. All commands are checked for the ok result, so the behaviour without using the new inputs is the same as before.

If the Json Query is set, it'll be applied to the query result. If json query result is undefined, the monitor will produce a failure. The Json query without expected value is basically checking if the value exists. If the expected value is set, it will be compared to the result.

Type of change

• User interface (UI)
• New feature (non-breaking change which adds functionality)

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

Testing

Test MongoDB
docker run --name test-mongodb -p 27017:27017 -e MONGO_INITDB_ROOT_USERNAME=admin -e MONGO_INITDB_ROOT_PASSWORD=admin mongo

Connection string: mongodb://admin:admin@localhost:27017
Test query: { "hello": 1 }

Here are the tests I ran:
mongodb-monitor-tests.json

[CommanderStorm]

Foremost, I think this sort of conflicts with #3919
@chakflying I think this is your area ⇒ I would rather not interfere:
what do you think about this?
Can this be integrated into your plan, or what level of refactoring need to be done to accommodate it?

Given the level of change (basically a rewrite) that this PR adds to the mongodb monitor, I think some additional changes are necessary.

• Please extract this monitor to the newer monitor-type variant of implementing monitors. see chore:extracted the group monitor to a different monitoring type #4395 for an example
• To be make verifying that this works simpler, please attach how you tested it to the description. (docker run..., query executed) ^^

[chakflying]

We discussed this a bit in #3857. Personally, I think the code change here is relatively small, and is good preparation if we wanted to support this generically in the future. I'm not against merging this if people wanted this feature.

[SebastianLng]

Thank you for the response, I migrated to the new monitor type and added some info for testing.

[chakflying]

Tested seems to work okay.

[CommanderStorm]

From my side there are no roadblocks.
Works as intended.

[CommanderStorm]

I don't know if this can be better/automatically tested via #4451

Honestly, such testcases should be build in #4451 first => we can expand this later

Thanks for the new feature!

All changes in this PR work as intended
⇒ merging with junior maintainer approval

[ekbaramundi]

Does this also work for MongoDB Atlas?

[CommanderStorm]

We have not tested that (we have tested the docker container), but you can report the findings.
I cannot see a reason why this should not work..