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{yen}

Knowledge packs

An agent with a knowledge store (a triple store such as quipu) can keep the fleet as a graph and query it with SPARQL. yen.lib.rdf.share r gives the eval result as sorted N-Triples: scopes, kinds, parents, active aspects, every routed element as a node with its origin, and errors. It adds a sha256 and a count.

modules/hosts.nix
{ yen, ... }:
{
  yen.environment.prod.domain = "example.com";
  yen.host.web.environment = yen.environment.prod;
  yen.host.db.environment = yen.environment.prod;
  yen.aspects.nginx = {
    at = yen.host.web;
    services = "nginx";
  };
}
<https://yen.dev/fleet/edge/32d0c078116c66f5> <https://yen.dev/fleet/yen/from> <https://yen.dev/fleet/scope/fleet:main> .
<https://yen.dev/fleet/edge/32d0c078116c66f5> <https://yen.dev/fleet/yen/origin> "aspect pack" .
<https://yen.dev/fleet/edge/32d0c078116c66f5> <https://yen.dev/fleet/yen/sink> "out" .
<https://yen.dev/fleet/edge/32d0c078116c66f5> <https://yen.dev/fleet/yen/to> <https://yen.dev/fleet/scope/fleet:main> .
<https://yen.dev/fleet/edge/a8c8404b6ebdf537> <https://yen.dev/fleet/yen/from> <https://yen.dev/fleet/scope/fleet:main/host:web> .
<https://yen.dev/fleet/edge/a8c8404b6ebdf537> <https://yen.dev/fleet/yen/origin> "aspect nginx" .
<https://yen.dev/fleet/edge/a8c8404b6ebdf537> <https://yen.dev/fleet/yen/sink> "services" .
<https://yen.dev/fleet/edge/a8c8404b6ebdf537> <https://yen.dev/fleet/yen/to> <https://yen.dev/fleet/scope/fleet:main/host:web> .
<https://yen.dev/fleet/instance/environment/prod> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <https://yen.dev/fleet/kind/environment> .
<https://yen.dev/fleet/instance/environment/prod> <https://yen.dev/fleet/yen/name> "prod" .
<https://yen.dev/fleet/instance/fleet/main> <http://www.w3.org/1999/02/22-rdf-syntax-ns#type> <https://yen.dev/fleet/kind/fleet> .
<https://yen.dev/fleet/instance/fleet/main> <https://yen.dev/fleet/yen/name> "main" .
…
result
{
  count = 31;
  sha256 = "7d5008a92e83eb458e7a6975294ade014204a79975d870a2c385e87a1ecd3f5e";
}

Same fleet, same hash

Section titled “Same fleet, same hash”

The triples are sorted, and yen gives the same answer whatever the file order. So two revisions compare by hash first. The docs check it: the files of this template, loaded in reverse order, give the same sha256.

A fleet can give its pack as a flake output:

modules/pack.nix
# The routing graph as a knowledge pack: sorted N-Triples with a sha256. Same fleet, same hash, any file order.
{ yen, ... }:
{
  yen.aspects.pack = {
    at = yen.kinds.fleet;
    out.rdfPack = removeAttrs (yen.lib.rdf.share {
      graph = yen.lib.graph;
      active = { };
      errors = [ ];
    }) [ "ntriples" ];
  };
}

Shapes

Section titled “Shapes”

yen.lib.rdf.shacl r gives SHACL shapes from the schema: one node shape per kind with scopes, yen:name required, yen:parent of the spawning kind, each field at most once, and sh:class for ref fields.

@prefix sh: <http://www.w3.org/ns/shacl#> .
@prefix xsd: <http://www.w3.org/2001/XMLSchema#> .
@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .


<https://yen.dev/fleet/kind/fleet> a sh:NodeShape ;
  sh:targetClass <https://yen.dev/fleet/kind/fleet> ;
  sh:property [ sh:path <https://yen.dev/fleet/yen/name> ; sh:minCount 1 ; sh:maxCount 1 ; sh:datatype xsd:string ; ] ;
  sh:property [ sh:path <https://yen.dev/fleet/yen/parent> ; sh:maxCount 1 ; ] ;
  .


<https://yen.dev/fleet/kind/host> a sh:NodeShape ;
  sh:targetClass <https://yen.dev/fleet/kind/host> ;
  sh:property [ sh:path <https://yen.dev/fleet/yen/name> ; sh:minCo…
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