fix(promunifi): accept a bracketed IPv6 http_listen in the health check

pkg/promunifi/collector.go

@@ -240,9 +240,8 @@ func (u *promUnifi) DebugOutput() (bool, error) {
 	}
 
 	// check the port
-	parts := strings.Split(u.HTTPListen, ":")
-	if len(parts) != 2 {
-		return false, fmt.Errorf("invalid listen address: %s (must be of the form \"IP:Port\"", u.HTTPListen)
+	if _, _, err := net.SplitHostPort(u.HTTPListen); err != nil {
+		return false, fmt.Errorf("invalid listen address: %s (must be of the form \"IP:Port\")", u.HTTPListen)
 	}
 
 	// Skip network binding check during health checks to avoid "address already in use"

pkg/promunifi/collector_test.go

@@ -20,3 +20,32 @@ func TestDebugOutputAcceptsUnsetHTTPListen(t *testing.T) {
 	assert.True(t, ok)
 	assert.Equal(t, defaultHTTPListen, u.HTTPListen)
 }
+
+func TestDebugOutputAcceptsAnIPv6HTTPListen(t *testing.T) {
+	poller.SetHealthCheckMode(true)
+	t.Cleanup(func() { poller.SetHealthCheckMode(false) })
+
+	tests := []struct {
+		listen string
+		valid  bool
+	}{
+		{"0.0.0.0:9130", true},
+		{"[::]:9130", true},
+		{":9130", true},
+		{"0.0.0.0", false},
+		{"0.0.0.0:9130:9131", false},
+	}
+
+	for _, test := range tests {
+		u := &promUnifi{Config: &Config{HTTPListen: test.listen}}
+
+		ok, err := u.DebugOutput()
+		assert.Equal(t, test.valid, ok, test.listen)
+
+		if test.valid {
+			require.NoError(t, err, test.listen)
+		} else {
+			require.Error(t, err, test.listen)
+		}
+	}
+}