GRM-144: feat(runner): enable IPv6 in rootless Docker via pasta network driver

2026-07-12 01:12:43 +00:00
parent 9f8adf14bc
commit 390fcb9d4b
4 changed files with 62 additions and 5 deletions
@@ -173,9 +173,21 @@ Each runner operates under a dedicated unprivileged system user. The Docker daem

 - User namespace mapping via `/etc/subuid` and `/etc/subgid` (range: 100000-165535)
 - Rootless Docker socket at `/run/user/<UID>/docker.sock`
- `slirp4netns` for user-mode networking
+- `pasta` for user-mode networking with IPv6 support (replaces `slirp4netns`, which lacks outgoing IPv6)
 - `fuse-overlayfs` for rootless container storage

+The rootless Docker daemon is configured via a systemd user override
+(`docker.service.d/override.conf`) that sets:
+
+- `DOCKERD_ROOTLESS_ROOTLESSKIT_NET=pasta` — use pasta as the network driver
+- `DOCKERD_ROOTLESS_ROOTLESSKIT_PORT_DRIVER=implicit` — pasta's native port forwarding
+- `DOCKERD_ROOTLESS_ROOTLESSKIT_FLAGS=--ipv6` — enable IPv6 routing
+
+The daemon.json enables IPv6 with a ULA subnet (`fd00:dead:beef::/48`)
+for container addressing. This ensures runner containers can reach
+both IPv4 and IPv6 services (e.g., the Gitea registry) without
+per-workaround DNS hacks.
+
 Containers launched by the runner never have root access to the host. The rootless Docker daemon is started as a systemd user service and persists via lingering.

 ### Secret handling