homelab: v0.5.0 — net/dns/metrics/logs probes (endpoint resolution)

The remaining verbs that pass the "saves reasoning, not just typing" test the
user posed mid-session: each encodes the non-obvious which-endpoint-reached-how
resolution otherwise re-derived every time. (Same test deprioritized node-ssh
and secret-get aliasing — thin wrappers over commands already known.)

- net check <host> [path]: two-legged reachability — external (public DNS→CF)
  vs internal (Traefik LB) — so you see WHERE a break is, not just that one path
  works. (live: surfaced the LB at 6ms vs CF 77ms.)
- dns lookup <name> [type]: Technitium (10.0.20.201) vs public (1.1.1.1) diff.
- metrics query "<promql>" / metrics alerts: Prometheus via the LB
  (prometheus-query.viktorbarzin.lan); alerts uses the synthetic ALERTS series
  since the query frontend has no /api/v1/alerts and Alertmanager has no ingress.
- logs query "<logql>" [--since 1h] [--limit N]: Loki range query via the LB.

All reach auth-free internal ingresses through the LB (Go form of
curl --resolve host:443:10.0.20.203) — no port-forward, no kubectl. In-cluster-
only endpoints (Alertmanager v2) deliberately out of scope. Verified live before
building; all five smoke-tested green.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

cli/probe_test.go

@@ -0,0 +1,49 @@
+package main
+
+import "testing"
+
+func TestQueryArg(t *testing.T) {
+	if got := queryArg([]string{"up"}, nil); got != "up" {
+		t.Errorf(`queryArg(["up"]) = %q, want "up"`, got)
+	}
+	if got := queryArg([]string{"up", "--json"}, nil); got != "up" {
+		t.Errorf(`--json should be dropped, got %q`, got)
+	}
+	// single quoted PromQL arrives as one token
+	if got := queryArg([]string{"count by (node) (up)", "--json"}, nil); got != "count by (node) (up)" {
+		t.Errorf(`quoted query mangled: %q`, got)
+	}
+	// value-flags and their values are skipped, query survives
+	vf := map[string]bool{"--since": true, "--limit": true}
+	if got := queryArg([]string{`{app="x"}`, "--since", "1h", "--limit", "50"}, vf); got != `{app="x"}` {
+		t.Errorf(`value-flag skipping failed: %q`, got)
+	}
+}
+
+func TestLabelStr(t *testing.T) {
+	got := labelStr(map[string]string{"__name__": "up", "job": "x", "instance": "y"})
+	if got != "up{instance=y,job=x}" { // __name__ extracted, rest sorted
+		t.Errorf("labelStr = %q", got)
+	}
+	if got := labelStr(map[string]string{"alertname": "Foo"}); got != "{alertname=Foo}" {
+		t.Errorf("labelStr (no __name__) = %q", got)
+	}
+}
+
+func TestOneLineList(t *testing.T) {
+	if got := oneLineList("  "); got != "(none)" {
+		t.Errorf("empty = %q, want (none)", got)
+	}
+	if got := oneLineList("a\nb"); got != "a, b" {
+		t.Errorf("multi = %q, want 'a, b'", got)
+	}
+}
+
+func TestHostOnly(t *testing.T) {
+	if got := hostOnly("foo.me/path"); got != "foo.me" {
+		t.Errorf("hostOnly = %q", got)
+	}
+	if got := hostOnly("foo.me"); got != "foo.me" {
+		t.Errorf("hostOnly = %q", got)
+	}
+}