move-server.sh: --docker-sock to give the container the target's Docker

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

docs/MOVING.md

@@ -47,6 +47,7 @@ Decide:
 | Folder for agent installs and `/tmp` | `--tools-dir` | `/mnt/disks/ssd/codecraft` |
 | Your projects | `--workspace` | `/mnt/user/projects` |
 | Owner of files (the container runs as this user) | `--uid`, `--gid` | Unraid default `99`/`100` (nobody:users); today `1000`/`1000` |
+| Docker of the new host for agents and terminals | `--docker-sock` | bind mount of `/var/run/docker.sock` plus its group (see below) |
 | Port and address | `--port`, `--bind` | `8787`; `0.0.0.0` if the reverse proxy runs on another machine or in another Docker network, `127.0.0.1` if it runs on the same host with host networking |
 
 ## Moving
@@ -57,12 +58,12 @@ On the **current host**, in the repository folder (where `.env` is):
 # 1. Look at the steps first (changes nothing)
 scripts/move-server.sh root@unraid:/mnt/user/appdata/codecraft \
   --workspace /mnt/user/projects --tools-dir /mnt/disks/ssd/codecraft \
-  --uid 99 --gid 100 --bind 0.0.0.0 --dry-run
+  --uid 99 --gid 100 --bind 0.0.0.0 --docker-sock --dry-run
 
 # 2. Move (same command without --dry-run)
 scripts/move-server.sh root@unraid:/mnt/user/appdata/codecraft \
   --workspace /mnt/user/projects --tools-dir /mnt/disks/ssd/codecraft \
-  --uid 99 --gid 100 --bind 0.0.0.0
+  --uid 99 --gid 100 --bind 0.0.0.0 --docker-sock
 ```
 
 What happens:
@@ -93,6 +94,21 @@ Afterwards:
 - **Clean up** on the old host when everything works: `docker rm codecraft`, later
   `docker volume rm codecraft-data`.
 
+## Docker socket (`--docker-sock`)
+
+With `--docker-sock` the container gets the new host's Docker: `/var/run/docker.sock` is bind
+mounted and the container joins the socket's group (the script reads its group id on the
+target). This is **root-equivalent access to the host**: whoever can start containers can mount
+any host folder.
+
+- Admins' agents and terminals (they run without sandbox) can use it.
+- Sandboxed users do not see the socket (the sandbox does not mount `/var/run`).
+- `docker` and `docker-compose` commands always need an approval, except in *bypass* mode.
+- The image has no Docker CLI; agents install the static CLI into their home when they need it
+  (on the tools disk with `--tools-dir`).
+
+The current host has the same setup in its local `docker-compose.override.yml` (group 997).
+
 ## Rollback
 
 Nothing is deleted on the old host. On Unraid stop the new container (`docker stop codecraft`),

scripts/move-server.sh

@@ -27,6 +27,10 @@
 #                        (/data/home), the users' homes (/data/users) and /tmp are bind
 #                        mounts from DIR/home, DIR/users and DIR/tmp (default: inside <dir>/data)
 #   --uid N --gid N      owner of data and workspace on the target (default: UID/GID of .env)
+#   --docker-sock        give the container the target's Docker (bind mount of
+#                        /var/run/docker.sock plus its group). Root-equivalent access to the
+#                        target host for admins' agents and terminals; sandboxed users do not
+#                        see it, and docker commands still need approval
 #   --port N             host port on the target (default: PORT of .env)
 #   --bind ADDR          bind address on the target (default: BIND_ADDR of .env or 127.0.0.1)
 #   --name NAME          container name on the target (default codecraft)
@@ -37,12 +41,13 @@
 #   --dry-run            show the steps only
 set -euo pipefail
 
-target="" ws_target="" tools_dir="" uid="" gid="" port="" bind="" name="codecraft"
+target="" ws_target="" tools_dir="" docker_sock=0 uid="" gid="" port="" bind="" name="codecraft"
 src_container="codecraft" src_volume="codecraft-data" ws_source="" stop=1 dry=0
 while (($#)); do
   case "$1" in
     --workspace) ws_target="$2"; shift ;;
     --tools-dir) tools_dir="$2"; shift ;;
+    --docker-sock) docker_sock=1 ;;
     --uid) uid="$2"; shift ;;
     --gid) gid="$2"; shift ;;
     --port) port="$2"; shift ;;
@@ -137,8 +142,15 @@ fi
 step "Copying the workspace (changes since the first pass)"
 sync_workspace
 remote "chown -R $uid:$gid $(q "$dir/data") $(q "$ws_target") ${tools_dir:+$(q "$tools_dir/home") $(q "$tools_dir/users")} 2>/dev/null || echo 'note: could not chown (not root) – check file owners'"
-# Bind mounts for the tools disk (compose lines and docker run flags).
+# Bind mounts for the tools disk and the Docker socket (compose lines and docker run flags).
-tool_mounts="" tool_flags=""
+tool_mounts="" tool_flags="" sock_compose="" sock_flags=""
+if (( docker_sock )); then
+  if (( dry )); then sock_gid=0; else
+    sock_gid=$(remote "stat -c %g /var/run/docker.sock") || fail "no /var/run/docker.sock on the target"
+  fi
+  sock_compose=$(printf '      - /var/run/docker.sock:/var/run/docker.sock\n    group_add:\n      - "%s"\n' "$sock_gid")
+  sock_flags="-v /var/run/docker.sock:/var/run/docker.sock --group-add $sock_gid "
+fi
 if [[ -n "$tools_dir" ]]; then
   tool_mounts=$(printf '      - %s/home:/data/home\n      - %s/users:/data/users\n      - %s/tmp:/tmp\n' "$tools_dir" "$tools_dir" "$tools_dir")
   tool_flags="-v $tools_dir/home:/data/home -v $tools_dir/users:/data/users -v $tools_dir/tmp:/tmp "
@@ -168,6 +180,7 @@ services:
       - $dir/data:/data
       - \${WORKSPACE}:/workspace
 $tool_mounts
+$sock_compose
     extra_hosts:
       - "host.docker.internal:host-gateway"
     shm_size: "1gb"
@@ -186,7 +199,7 @@ val() { sed -n "s/^\$1=//p" .env | tail -1; }
 docker rm -f $name >/dev/null 2>&1 || true
 exec docker run -d --name $name --restart unless-stopped --user "\$(val UID):\$(val GID)" \\
   -p "\$(val BIND_ADDR):\$(val PORT):8787" --env-file .env \\
-  -v $dir/data:/data -v "\$(val WORKSPACE):/workspace" $tool_flags\\
+  -v $dir/data:/data -v "\$(val WORKSPACE):/workspace" $tool_flags$sock_flags\\
   --add-host host.docker.internal:host-gateway --shm-size 1g \\
   --security-opt seccomp=$dir/docker/seccomp-sandbox.json \\
   --security-opt apparmor=unconfined --security-opt systempaths=unconfined \\