Keep mesh and node config with their history, and move whole-mesh module layers onto each assigned node (hq issue 630)

An assignment is one module on one node, so a new whole-mesh layer is refused and the ones held are laid under each assigned node's layer, every replaced layer kept, so no machine composes differently.
2026-10-13 13:14:42 +00:00
parent fba6a7c454
commit df5254f308
3 changed files with 459 additions and 2 deletions
@@ -0,0 +1,92 @@
+-- A config value comes from four sources, the last set winning (novox/hq issue 630): the module's
+-- default, mesh config, node config, and the module's own value on the node. Mesh config and node config
+-- hold values only for the predefined keys, a fixed list kept in the catalogue (`predefined.json`). An
+-- assignment is one module on one node: there is no module layer for the whole mesh any more.
+
+-- The list of predefined keys, as the catalogue's predefined.json last said it. Replaced whole when a
+-- build of the catalogue carries the file; `repository` and `commit` say which.
+create table predefined_key (
+    key        text        primary key,
+    type       text        not null check (type in ('number', 'string', 'boolean')),
+    why        text        not null,
+    repository text,
+    commit     text,
+    listed_at  timestamptz not null default now()
+);
+
+-- Mesh config (node null) and node config: one value per predefined key, and per node. Not a foreign key
+-- to predefined_key: a key the list drops keeps its value, said as reaching nothing, rather than losing it.
+create table config (
+    key    text        not null,
+    node   uuid        references node(id) on delete cascade,
+    value  jsonb       not null,
+    set_at timestamptz not null default now(),
+    set_by text,
+    why    text        not null
+);
+create unique index config_for_the_mesh on config (key) where node is null;
+create unique index config_for_a_node   on config (key, node) where node is not null;
+
+-- Every value that was replaced or cleared, with who set it and why, and who replaced it and why.
+create table config_history (
+    key          text        not null,
+    node         uuid        references node(id) on delete cascade,
+    value        jsonb       not null,
+    set_at       timestamptz,
+    set_by       text,
+    why          text,
+    replaced_at  timestamptz not null default now(),
+    -- set · clear
+    replaced_by  text        not null,
+    replaced_why text
+);
+create index config_history_by_key on config_history (key, node, replaced_at desc);
+
+-- The module layer for the whole mesh goes: each one is laid under the layer of every node the module is
+-- assigned to — the mesh's values first, the node's over them, maps merged key by key as composition
+-- merged them — so every machine composes what it did. Every layer replaced, and the mesh-wide layer
+-- itself, is kept in settings_history (ADR 0217) with the reason `moved-to-nodes`. A mesh-wide layer of
+-- a module assigned nowhere is kept in the history only: no machine read it.
+create function pg_temp.config_630_merge(under jsonb, over jsonb) returns jsonb language plpgsql immutable as $$
+declare
+    merged jsonb;
+    k      text;
+begin
+    if jsonb_typeof(under) is distinct from 'object' or jsonb_typeof(over) is distinct from 'object' then
+        return over;
+    end if;
+    merged := under;
+    for k in select jsonb_object_keys(over) loop
+        if merged ? k then
+            merged := jsonb_set(merged, array[k], pg_temp.config_630_merge(merged -> k, over -> k));
+        else
+            merged := merged || jsonb_build_object(k, over -> k);
+        end if;
+    end loop;
+    return merged;
+end
+$$;
+
+insert into settings_history (node, module, values, set_at, replaced_by, set_by)
+select t.node, t.module, t.values, t.set_at, 'moved-to-nodes', t.set_by
+  from settings t
+  join settings s on s.module = t.module and s.node is null
+ where t.node is not null
+   and exists (select 1 from assignment a where a.node = t.node and a.module = t.module);
+
+insert into settings_history (node, module, values, set_at, replaced_by, set_by)
+select null, module, values, set_at, 'moved-to-nodes', set_by from settings where node is null;
+
+insert into settings (node, module, values, set_at, set_by)
+select a.node, s.module, s.values, now(),
+       coalesce(s.set_by || '; ', '') || 'moved from the whole mesh''s layer to this node''s (novox/hq issue 630)'
+  from settings s
+  join assignment a on a.module = s.module
+ where s.node is null
+on conflict (node, module) where node is not null
+do update set values = pg_temp.config_630_merge(excluded.values, settings.values),
+              set_at = now(),
+              set_by = coalesce(settings.set_by || '; ', '') ||
+                       'the whole mesh''s layer laid under it (novox/hq issue 630)';
+
+delete from settings where node is null;