Code change:
${optionalString cfg.caching.apcu "'memcache.local' => 'OCMemcacheAPCu',"} 'log_type' => 'syslog', 'log_level' => '${builtins.toString cfg.logLevel}', <del> ${optionalString (cfg.config.overwriteProtocol != null) "'overwriteprotocol' => '${cfg.config.overwriteProtocol}',"} </del> <ins> ${optionalString (c.overwriteProtocol != null) "'overwriteprotocol' => '${c.overwriteProtocol}',"} ${optionalString (c.dbname != null) "'dbname' => '${c.dbname}',"} ${optionalString (c.dbhost != null) "'dbhost' => '${c.dbhost}',"} ${optionalString (c.dbport != null) "'dbport' => '${toString c.dbport}',"} ${optionalString (c.dbuser != null) "'dbuser' => '${c.dbuser}',"} ${optionalString (c.dbtableprefix != null) "'dbtableprefix' => '${toString c.dbtableprefix}',"} ${optionalString (c.dbpass != null) "'dbpassword' => '${c.dbpass}',"} ${optionalString (c.dbpassFile != null) "'dbpassword' => nix_read_pwd(),"} 'dbtype' => '${c.dbtype}', 'trusted_domains' => ${writePhpArrary c.extraTrustedDomains}, </ins> ]; ''; occInstallCmd = let <del> c = cfg.config; adminpass = if c.adminpassFile != null then ''"$(<"${toString c.adminpassFile}")"'' else ''"${toString c.adminpass}"''; </del> dbpass = if c.dbpassFile != null then ''"$(<"${toString c.dbpassFile}")"'' else if c.dbpass != null then ''"${toString c.dbpass}"'' else null; <ins> adminpass = if c.adminpassFile != null then ''"$(<"${toString c.adminpassFile}")"'' else ''"${toString c.adminpass}"''; </ins> installFlags = concatStringsSep " n    " (mapAttrsToList (k: v: "${k} ${toString v}") { "--database" = ''"${c.dbtype}"'';

Related discussion:
text: If nobody else wants to take over, I'd volunteer to do this during the next week as investing time on improving the nextcloud module is one item on my todo list :) I was aware of being stateful, but thanks a lot for linking the corresponding ticket! I'll have a look at this as soon as I have sufficient time to :)
In the light of this issue, what's the correct way to upgrade nextcloud to a new major version? Do I just pull a newer , upgrade my system and hope that the systemd job will do the right thing?
The service runs an that should apply all changes like database migrations needed for the new Nextcloud version (beware, downgrades aren't possible). As long as you let Nextcloud do its job, you shouldn't get that much issues. IMHO the actual problem here is the configuration of the software within Nix(OS).
just a simple question (could not come to a conclusion after the lengthy thread) but I recently updated my nextcloud via nixops deploy and the update disabled the calendar module. Did I mess up or is that expected ? any way to configure this from nix ?
Assuming that you installed the calendar module via the UI, it is installed in . The beginning of my config reads: So in principle nextcloud can edit the apps installed via the web interface (otherwise you couldn't install them via the interface in the first place).
I don't think there's anything actionable here - the nextcloud nixos module is limited by how Nextcloud (imperatively) manages its configuration. The current state is properly documented in , and we raised our concerns to upstream in - closing this issue, feel free to reopen if there's more to be done.
I think one actionable item would be to have the nextcloud service fail with an explicit error if the configuration being used is not compatible with the configuration defined in the .nix. At least the user would be warned in practice that configuration is not really applied, and not only by the manual that they are relatively unlikely to actually read. Reopening for now, feel free to reclose if you think that's not a reasonable “solution” :)
The problem is we don't know whether the configuration on disk containing database connection information () differs from the one that would be generated through an installation via - we don't render the configuration on our own, but the installer writes it out as a side-effect.