config: initial loading & env overrides

Signed-off-by: NotAShelf <raf@notashelf.dev>
Change-Id: Iaa7401a20506a084a2a16882e61ea0bc6a6a6964

config.example.yaml

@@ -0,0 +1,30 @@
+server:
+  listen: ":8080"
+  read_timeout: 30s
+  write_timeout: 30s
+
+upstreams:
+  - url: "https://cache.nixos.org"
+    priority: 10
+    public_key: "cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY="
+
+  # Try without a public key
+  - url: "https://nix-community.cachix.org"
+    priority: 20
+
+cache:
+  db_path: "/var/lib/ncro/routes.db"
+  max_entries: 100000
+  ttl: 1h
+  latency_alpha: 0.3
+
+mesh:
+  enabled: false
+  bind_addr: "0.0.0.0:7946"
+  peers: []
+  private_key: "/etc/ncro/node.key"
+  gossip_interval: 30s
+
+logging:
+  level: "info"
+  format: "json"