meta/meeting-notes/2024-11-20-architecture-meetup/2024-11-20-architecture-meetup.md

​Architecture meetup 2024-11-20

13:30 -  15:00

Agenda Times are approx. Less is better ;) 
13:30 - 13:35 Goals of the meeting (~5min)
13:35 - 14:15 Diagram discussion (~40min)
14:15 - 14:35 Status of the project (~20min)
14:35 - 14:55 Roles & responsibilities (~25min) 
14:55 - 15:00 FOSSDEM (~5min) 

Attendees: Bjorn, Ronny, Richard, Kevin, Nicolas, Gheorghe, Valentin

Goals:
	*     Clarify uncertainties and "freeze" the architecture

Notes:
	* Robert and Koen are missing today, both are critical
	* Management layer:
		* IdentityManagement should be clarified as Authorization, Authentication, Accounting (AAA)
		* The Nix-Panel to used by the operator (our "customer") with high-level parameters
			* operator's email
			* DNS zone
			* booked storage and compute
			* etc
		* TBD in how much this will be greenfield, see architecture discussion from a few weeks ago
		* About the central database (multiples)
		* Q: what is the datamodel? TBD in more detail.  
			* State of the system per operator
			* AAA stuff 
			* Operator bespoke info
			* Provider bespoke info
				* upstream DNS config
				* Netbox: provider side (physical network layout & hardware) 
		* Q: What's the role  of NixOps4 here?
			* Valentin: NixOps4 merely provides a mechanism. The policy is implemented by "resource providers" which are domain-specific and plugged into NixOps4 to CRUD the various data sources
		* TO DO: There are no "use cases" yet to describe how the services works; e.g setting up a service like Pixelfed etc. Basically a case to describe how the components work together. 
			* (some discussion on the various representations of the system: component dependency graph, data flow graph for how deployments come together, user stories for the various actors)
			* Valentin proposes to focus on the component dependencies for now, as the current diagram already mostly represents those 
				* can sketch user stories on the side
		* "Nix-configuration" and Proxmos are merely resource providers for NixOps4
		* TODO: Glossary for definitions (make sure we all speak the same language).
		* Gheorghe proposes to annotate each box with the component type (e.g. "virtualisation provider") and [at least one, if there are multiple planned] concrete implementation (e.g. "proxmox")
		* Ronny: there may be services that happen not to run under NixOS but some other Linux distro
			* We will need another configuration system for those, e.g. Ansible
				* This would be another resource provider for NixOps4
			* We shouldNix declare it out of scope, since NixOS is the more natural thing to do, or hack it together with shell scripts if absolutely required
				* We currently don't have services that aren't - and defintely none that can't be - nixified
				* Also, centrally managed systems, such as provider-side DNS management, can be handled by the provider classically, e.g. on Debian
					* Our particular target deSEC would be expensive to package for NixOS, but we need it exactly once per provider and it won't be redeployed
		* NixOS services:
			* The only difference between "Services" and "FediServices" is that "FediServices" have federation
				* More nuanced: Fediverse services are intended to be used by the general public, while the others are more interesting for academic institutions
					* This is a distinction per work package
			* Technically, all of them are NixOS modules with configurations that are somewhat specific to our architecture
			* Unspecified requirement: Backups for all of these
				* From previous discussions: storage is one of
					* Service data: Block storage (ZFS), and snapshots are pulled on the provider side
						* Essentially anything that can't be stored as blob storage
					* User data: Blob storage (e.g. Garage), could optionally be replicated to compatible services
						* Q: is this already available in Garage or would we need to build it, and is it relevant to our mission?
				* Storage needs to be rewired for each service so the data actually lands where it should
					* Need to decide whether it's worth the time investment on a case-by-case basis
		* "Core services":
			* secrets management is more of a concern for deployments (as a NixOps4 resource provider)
				* Secrets are a resource & need a resource provider plugin.
				* Which resourceproviders does NixOps need to talk & their context.
			* The purpose of this block is to signify that some services are mandatory for an operator-side deployment, but they exist already and only need to be interfaced with via NixOps4
				* For example, there is a DNS management system and an email server, and a deployment merely needs to register with them
					* TODO: label this in the architecture diagram
				* TODO: move it into the "Management" block, maybe rename this to "existing" or "pre-defined" services
			* TODO: clarify mapping between archtectural components and use case actors, refine naming
			* 

Due to other meetings we had to stop here. We still have to discuss these topics from the agenda: 
14:15 - 14:35 Status of the project (~20min)
14:35 - 14:55 Roles & responsibilities (~25min) 
14:55 - 15:00 FOSSDEM (~5min)