Build Housecarl 0.1.0: the nftables firewall manager

Zones, address sets (IPv4 and IPv6 mixed, dynamic sets with timeouts) and
services, ordered rules in the early, input, forward and output chains,
port forwards with hairpin NAT and IPv6 pinholes, source NAT, redirects,
and switchable built-ins (loopback, conntrack, ICMPv6, antispoofing, MSS
clamping, DHCPv6 client, flowtable). Every change is validated, checked
with nft -c and applied in one transaction to Housecarl's own table,
inet housecarl; changes made over the network roll back unless
confirmed, and the confirmed ruleset is loaded at boot by
housecarl-ruleset.service. An empty configuration applies nothing.

Also: hit counters and the drop log (nflog), 'hc import' of an existing
nftables ruleset and 'hc takeover', the hc CLI, the REST API and the web
UI, users, scoped tokens (sets:write:NAME), the audit log, the web UI's
certificate through Jarl, Debian packages, docs, unit tests with real
nft 1.1.3, and an e2e test with real traffic (71 checks).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

internal/web/static/assets/pages/dashboard.js

@@ -0,0 +1,65 @@
+// Dashboard: the ruleset's state, problems, interfaces, the busiest rules
+// and the latest drops.
+import { h, mount, table, badge, problemsList, time } from "../ui.js";
+import { get, can } from "../api.js";
+import { onLeave } from "../app.js";
+import { describe, hits, humanCount } from "../widgets.js";
+
+export async function render(el) {
+  const draw = async () => {
+    const st = await get("/status");
+    const config = can("config", false), logs = can("log", false);
+    const [rules, cs, log] = await Promise.all([
+      config ? get("/rules") : [],
+      logs ? get("/counters").then((c) => c.counters).catch(() => ({})) : {},
+      logs ? get("/log", { limit: 8 }).catch(() => []) : [],
+    ]);
+    const busiest = rules.filter((r) => cs["r" + r.id] && cs["r" + r.id].packets > 0)
+      .sort((a, b) => cs["r" + b.id].packets - cs["r" + a.id].packets).slice(0, 8);
+    const card = (label, value, sub, href) => {
+      const body = [h("div", { class: "label" }, label), h("div", { class: "value" }, String(value)), h("div", { class: "sub" }, sub)];
+      return href ? h("a", { class: "card link", href }, body) : h("div", { class: "card" }, body);
+    };
+    const policyDrops = (c) => cs["p-" + c] ? humanCount(cs["p-" + c].packets) : "–";
+    mount(el,
+      h("div", { class: "page-head" }, h("div", { class: "grow" }, h("h1", null, "Dashboard"))),
+      st.unconfigured ? h("div", { class: "msg info" }, "Nothing is configured yet, so Housecarl applies no ruleset. Write the rules that let you in (SSH, this web UI) first: the input policy drops what no rule accepts. Or ",
+        h("a", { href: "#/import" }, "import your ruleset"), ".") :
+        !st.applied ? h("div", { class: "msg err" }, "The ruleset isn't in force: ", st.apply_error) : null,
+      st.other_tables.length ? h("div", { class: "msg info" }, "Other tables in the ruleset: ", h("span", { class: "mono" }, st.other_tables.join(", ")),
+        ". A packet must get past them too. Once Housecarl's ruleset replaces one, 'hc takeover' deletes it.") : null,
+      h("div", { class: "cards" },
+        card("Ruleset", st.applied ? "in force" : st.unconfigured ? "none yet" : "not in force", "table inet housecarl", null),
+        card("Rules", st.counts.rule, st.counts.zone + " zones · " + st.counts.set + " sets", "#/rules"),
+        card("NAT", st.counts.forward + st.counts.snat + st.counts.redirect, st.counts.forward + " port forwards", "#/nat"),
+        card("Dropped by policy", policyDrops("input") + " / " + policyDrops("forward"), "input / forward", logs ? "#/log" : null),
+        card("Problems", st.problems.length, st.problems.length ? "see below" : "none", null)),
+      st.problems.length ? h("div", { class: "panel" }, h("h2", null, "Problems"), problemsList(st.problems)) : null,
+      h("div", { class: "panel" }, h("h2", null, "Interfaces"), table([
+        { label: "Interface", render: (i) => [h("span", { class: "dot " + (i.up ? "ok" : "err") }), h("span", { class: "mono" }, h("strong", null, i.name))] },
+        { label: "Zone", render: (i) => i.zone || h("span", { class: "muted" }, "none") },
+        { label: "Addresses", render: (i) => h("span", { class: "mono small" }, i.addresses.join(", ")) },
+      ], st.interfaces.filter((i) => i.name !== "lo"))),
+      busiest.length ? h("div", { class: "panel" },
+        h("div", { class: "panel-head" }, h("h2", null, "Busiest rules"), h("a", { class: "button small", href: "#/rules" }, "All rules")),
+        table([
+          { label: "Chain", render: (r) => r.chain },
+          { label: "Rule", render: (r) => r.raw || describe(r) },
+          { label: "Action", render: (r) => badge(r.action, { accept: "ok", drop: "err", reject: "warn" }[r.action]) },
+          { label: "Hits", render: (r) => hits(cs, "r" + r.id) },
+          { label: "Comment", render: (r) => r.comment },
+        ], busiest)) : null,
+      log.length ? h("div", { class: "panel" },
+        h("div", { class: "panel-head" }, h("h2", null, "Latest logged packets"), h("a", { class: "button small", href: "#/log" }, "The log")),
+        table([
+          { label: "When", render: (e) => time(e.time) },
+          { label: "Why", render: (e) => e.prefix },
+          { label: "From", render: (e) => h("span", { class: "mono" }, e.source) },
+          { label: "To", render: (e) => h("span", { class: "mono" }, e.destination, e.destination_port ? ":" + e.destination_port : "") },
+          { label: "Protocol", render: (e) => e.protocol },
+        ], log)) : null);
+  };
+  await draw();
+  const t = setInterval(() => { if (!document.hidden) draw().catch(() => {}); }, 15000);
+  onLeave(() => clearInterval(t));
+}