LAN-access: fix Include scope + read-only ControlPath, add ssh-lan.conf & RFC1918 autojump

- Fix: Include ~/.ssh/config was scoped to the Host host/mac block, so dssh <peer> by name fell back to SSH defaults. Emit Host * scope reset before every Include. - Fix: redirect ControlPath to writable ~/.ssh-local sidecar (Mac config's ~/.ssh/cm path is read-only in the container, broke multiplexed hosts). - Add: Include host-owned ~/.config/devbox-shell/ssh-lan.conf for named-peer ProxyJump overrides (keeps image generic; peer names stay host-side). - Add: opt-in DEVBOX_LAN_AUTOJUMP_PRIVATE=1 RFC1918 catch-all for roaming. - Docs: README/.env.example/AGENTS/CHANGELOG + new ssh-lan.conf.example.
2026-06-04 00:52:42 +02:00
parent 053dac5308
commit a56a5846a5
6 changed files with 194 additions and 17 deletions
@@ -37,6 +37,30 @@
 #       jump to authenticate. If unset we still generate the config but print
 #       a hint with the public key to authorize on the host.
 #   DEVBOX_HOST_ALIAS — host hostname to reach (default host.docker.internal).
+#   DEVBOX_LAN_AUTOJUMP_PRIVATE = 0 (default) | 1
+#       1 → also emit a catch-all that ProxyJumps *any* RFC1918 (private) IP
+#       through the host. Lets bare `dssh user@<private-IP>` work on whatever
+#       LAN the (roaming) host is currently joined to, without naming peers.
+#       Matches by the address you TYPE, not the resolved HostName, so it never
+#       overrides named hosts that already carry their own ProxyJump.
+#
+# HOST-OWNED PEER POLICY (portable; keeps this image generic)
+#   Named LAN peers are facts about a *specific* host's network, not about the
+#   image — a roaming laptop sees different LANs. So we never bake peer names
+#   here. Instead, if the host bind-mounts ~/.config/devbox-shell/ssh-lan.conf
+#   (the same devbox-shell bridge dir used for shared aliases), we Include it
+#   *before* ~/.ssh/config. That file holds the host's own jump overrides, e.g.
+#       Host pve pve-2 pbs-vm
+#           ProxyJump host
+#   First-value-wins means ProxyJump is taken from there while HostName/User/
+#   IdentityFile are inherited from the matching block in ~/.ssh/config.
+#
+# SCOPING NOTE (important)
+#   `Include` is scoped to the enclosing Host/Match block. So every Include
+#   below is preceded by a bare `Host *` to reset the active context to
+#   match-all — otherwise the included config would only apply when targeting
+#   `host`/`mac` and named peers like `pve` would silently fall back to ssh
+#   defaults.
 #
 # Idempotent: re-renders the config every run (cheap); never regenerates the
 # key. Always non-fatal — never blocks container startup.
@@ -84,9 +108,51 @@ if [ -n "${HOST_SSH_USER:-}" ]; then
  USER_LINE="    User ${HOST_SSH_USER}"
 fi

-INCLUDE_LINE=""
+# Optional host-owned named-peer jump overrides (portable: lives on the host,
+# not in the image). Included BEFORE ~/.ssh/config so its ProxyJump wins.
+SSH_LAN_CONF="${HOME}/.config/devbox-shell/ssh-lan.conf"
+LAN_CONF_BLOCK=""
+if [ -r "$SSH_LAN_CONF" ]; then
+  LAN_CONF_BLOCK=$(cat <<'EOF'
+
+# Host-owned named-peer jump overrides (bind-mounted; edit on the host).
+# Scope reset to match-all so the Include applies to every target host.
+Host *
+Include ~/.config/devbox-shell/ssh-lan.conf
+EOF
+)
+fi
+
+# Optional opt-in RFC1918 catch-all: ProxyJump every private IP through the
+# host. Matches the typed address, never the resolved HostName, so named hosts
+# with their own ProxyJump are unaffected. Network-agnostic → roaming-safe.
+AUTOJUMP_BLOCK=""
+if [ "${DEVBOX_LAN_AUTOJUMP_PRIVATE:-0}" = "1" ]; then
+  AUTOJUMP_BLOCK=$(cat <<'EOF'
+
+# RFC1918 auto-jump (DEVBOX_LAN_AUTOJUMP_PRIVATE=1): reach any private IP on
+# the host's CURRENT LAN via bare `dssh user@<ip>`. Public IPs are unmatched
+# and go direct via the container's NAT egress. NOTE: also matches the
+# container's own bridge subnet and any private IP the host can't actually
+# reach — for non-LAN private hosts behind a different jump, use their named
+# entry (which matches first by name and keeps its own ProxyJump).
+Host 10.* 192.168.* 172.16.* 172.17.* 172.18.* 172.19.* 172.20.* 172.21.* 172.22.* 172.23.* 172.24.* 172.25.* 172.26.* 172.27.* 172.28.* 172.29.* 172.30.* 172.31.*
+    ProxyJump host
+EOF
+)
+fi
+
+INCLUDE_BLOCK=""
 if [ -r "${HOME}/.ssh/config" ]; then
-  INCLUDE_LINE="Include ~/.ssh/config"
+  INCLUDE_BLOCK=$(cat <<'EOF'
+
+# Your own target hosts. Scope reset to match-all so this Include applies to
+# every target (an Include is otherwise scoped to the enclosing Host block).
+# Add 'ProxyJump host' to LAN entries here (or in ssh-lan.conf above).
+Host *
+Include ~/.ssh/config
+EOF
+)
 fi

 cat > "$CONFIG" <<EOF
@@ -95,9 +161,15 @@ cat > "$CONFIG" <<EOF
 # (or the dssh / dscp aliases). See the script header for the full rationale.

 # ~/.ssh is typically mounted read-only, so keep our own known_hosts here.
+# Also redirect ControlPath into the writable sidecar: the bind-mounted
+# ~/.ssh/config commonly sets 'ControlPath ~/.ssh/cm/...' for CGNAT multiplexing,
+# but ~/.ssh is read-only here so the master socket can't be created and those
+# hosts fail to connect. First-value-wins: setting it here (before the Include)
+# overrides the read-only path for every host. Harmless when ControlMaster is off.
 Host *
    UserKnownHostsFile ~/.ssh-local/known_hosts
    StrictHostKeyChecking accept-new
+    ControlPath ~/.ssh-local/cm/%r@%h:%p

 # The container host (OrbStack / Docker Desktop). 'host' and 'mac' are aliases.
 Host host mac
@@ -109,10 +181,9 @@ ${USER_LINE}
    ControlPath ~/.ssh-local/cm/%r@%h:%p
    ControlPersist 4h
    ServerAliveInterval 30
-
-# Your own target hosts: add 'ProxyJump host' to their entries in your
-# bind-mounted ~/.ssh/config, pulled in below.
-${INCLUDE_LINE}
+${LAN_CONF_BLOCK}
+${AUTOJUMP_BLOCK}
+${INCLUDE_BLOCK}
 EOF
 chmod 600 "$CONFIG" 2>/dev/null || true