choose server_name at installation

[Thatoo]

I was reading synapse documentation and I discovered that the server_name could be different than the real address of the server. It is explain here : https://github.com/matrix-org/synapse#setting-up-federation
So we can run a server at synapse.example.com, but have our Matrix user-ids look like @user:example.com instead of @user:synapse.example.com .
It could be pretty cool for yunohost admin to be able to choose the server_name before install and then when the install is finish, to get the correct SRV record to put in the DNS record of his/her registrar's interface. and also the homeserver.yaml being already set with the desired server_name.

I know I would have loved that!
Now, I don't dare to make the change of my homeserver.yaml because of that sentence : "If you've already started Synapse and a database has been created, you will have to recreate the database."
I'm afraid all users loose their data. I don't know what imply to recreate the database. Will users loose their data? the ID and key device check (for encryption...)?
And first of all, I don't know how to recreate this database.

I guess, this would be a very welcomed enhancement.

[Thatoo]

Does anyone know how we could change the server_name after install on a prod server of yunohost?
Is it even possible or way to risky and better keep the @user:synapse.domaine.tld and forget about the nicer @user:domaine.tld ?

[Thatoo]

I tried to understand what would need to change in files to take in account the choice of server_name at install and I've made some modifications. As I'm new, I hope I didn't make mistakes and what I did is understandable.
If I'm on the good track or completely wrong or something in between, don't hesitate to tell me. I just want to try to help.

[gnouts]

I would have been interested in that, too.

@Thatoo From what I've been told, it's not possible to change this parameter, unless you do a complete reinstall and loose data and federation. So it's basically a start from crash.

Adding a server_name parameter (with short description of what it implies) at installation doesn't seem too complicated.
Changing server_name at install here , and in config here, seems enough. I'll try to setup a test server to confirm this, if time is gentle with me...

[Josue-T]

You can do it if you want...

[Thatoo]

I had this same understanding too so I decided to keep on with what I have already.
I tried to look into the code to see what needed to change for fun but I guess it's out of my computing abilities as I don't know much about coding. You can have a look at what I did in here if you know how to display differences between my fork and the original (I don't even know how to do that :-) : https://github.com/Thatoo/synapse_ynh
I remember I had found more than two things to be changed... and as I was not sure what I was doing and if it was enough, I didn't say anything.

I found how to make comparisons. Here they are :
master...Thatoo:patch-1
and
master...Thatoo:patch-2

[Thatoo]

@gnouts did you succeed to make it working. If it's set before matrix 1.0, it might be an idea to make a reinstall when 1.0 releases.

[Thatoo]

@Josue-T did you have time to glance what I did. I'd like to know if I was on the good track or if I was doing nonsense.

[Josue-T]

@Thatoo , maybe you can create one PR with your patch. Because, as I see it's not bad, but some other change are also needed... and with a PR it' more easy to discuss about some part of code.

Sorry but I quite busy these time...

[gnouts]

@Thatoo I did some hack and managed to get a working synapse install with my account being @nouts:test.com while having synapse installed on matrix.test.com. Though I didn't tested if federation was actually working and I don't kown how it impact upgrade/backup/restore.
I'll do a PR if someone want to try it.
Also I don't really know how to test federation as I use fake domain on a virtual network in a VM... (or actually, I know but it's a heavy setup for testing ^^' )

[Thatoo]

gnouts wrote the PR faster than me.

[Thatoo]

I have a problem with the update script : #136

[Thatoo]

Withe the PR of @gnouts, #119 and mine, #136, it is possible to have this server_name option at install.
With the .well-known solution, it is working out of the box, without any need of registering any SRV record into DNS.
Once our PR merged, this comment could be closed.
Thank you @gnouts for starting the job.

[Josue-T]

Closed by #119