Set default MongoDB version to 7.0.25

[axllent]

Resolves #2680

Changes

• Sets the default MongoDB version in Ansible to version 7.0.25
• Sets the default MongoDB version in DigitalOcean to version 7

Tests

This has been tested with a new DigitalOcean deployment. I assume there is also a level of automated tests which I am unfamiliar with.

Comments

Should the Docker image version be exact (ie: docker.io/library/mongo:7.0.25), or should it maybe be scoped to docker.io/library/mongo:7 to include all future 7.* releases? If this needs changing then please let me know and I'll update the MR.

[ikreymer]

We've tested Mongo 8 locally as well on DigitalOcean cluster and Browsertrix works well with it.
However, Mongo doesn't update directly from 6 -> 8, so this change could break existing users that are on a local Mongo 6, as first have to upgrade to Mongo 7, or, possible update the feature compatibility in a migration to be at 7.0:
https://www.mongodb.com/docs/upcoming/release-notes/8.0-upgrade-standalone/#prerequisites

Otherwise, the 8.0 image will exit.. need to test some more to figure out best way to do this to avoid breaking existing deployments.

[axllent]

Thanks @ikreymer, and that's a good point about the upgrade between 6 -> 8. I guess the alternative would be to switch to v7 now, and in a year or so switch to v8? That should allow more than enough time for everyone to have updated their systems.

If you would like me to update my PR then just let me know. Also please note my question in the comment in my PR ~ that question would apply to v7 as well.

[ikreymer]

Thanks @ikreymer, and that's a good point about the upgrade between 6 -> 8. I guess the alternative would be to switch to v7 now, and in a year or so switch to v8? That should allow more than enough time for everyone to have updated their systems.

If you would like me to update my PR then just let me know. Also please note my question in the comment in my PR ~ that question would apply to v7 as well.

Yeah, I think maybe safest would be to update to 7, and then looks like we need to manually set that field, eg: db.adminCommand( { setFeatureCompatibilityVersion: "7.0", confirm: true } ) after upgrading to 7.
And in a future release, we can upgrade to 8.
I think pinning to specific version is safest, looks like for 7, that'd be 7.0.25.

Of course, for anyone who wants to upgrade sooner can then also override mongo_image in their local overrides.

I did that for testing locally: first deployed with 7.0.25, then patched in mongosh via the adminCommand, then updated to 8.0.15

But I think we'd want the upgrade to be as smooth as possible so users don't have to do that.

[axllent]

@ikreymer No problem - I've updated the PR to use 7.0.25 instead of 8. I haven't a clue how one would go about running the db.adminCommand( { setFeatureCompatibilityVersion: "7.0", confirm: true } ) part, but I'll leave that up to you as it will be in the application itself.

[ikreymer]

We need to add a migration in the db to ensure a smooth upgrade, will push to further release so we can test this better.