moar scripts

home/scripts/lxc/lab-addkey.sh

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+#!/usr/bin/env bash
+set -euo pipefail
+
+usage() {
+  cat <<EOF
+Usage: lab-addkey <user> <keyfile|key-string>
+
+Appends an SSH public key to both:
+  - the host user's ~/.ssh/authorized_keys
+  - the container's /root/.ssh/authorized_keys
+
+Examples:
+  lab-addkey alice /tmp/alice-laptop.pub
+  lab-addkey alice "ssh-ed25519 AAAA... user@host"
+EOF
+  exit 1
+}
+
+[[ $# -lt 2 ]] && usage
+
+USER="$1"
+KEY_INPUT="$2"
+
+# resolve key content
+if [[ -f "$KEY_INPUT" ]]; then
+  KEY=$(cat "$KEY_INPUT")
+else
+  KEY="$KEY_INPUT"
+fi
+
+# basic sanity check
+if [[ ! "$KEY" =~ ^ssh- ]] && [[ ! "$KEY" =~ ^ecdsa- ]]; then
+  echo "ERROR: doesn't look like a valid SSH public key" >&2
+  exit 1
+fi
+
+# resolve container
+if [[ -f "/home/${USER}/.lxc-container" ]]; then
+  CONTAINER=$(cat "/home/${USER}/.lxc-container")
+else
+  echo "ERROR: no container found for user '${USER}'" >&2
+  exit 1
+fi
+
+# --- add to host user ---
+HOST_AUTHKEYS="/home/${USER}/.ssh/authorized_keys"
+mkdir -p "/home/${USER}/.ssh"
+if grep -qF "$KEY" "$HOST_AUTHKEYS" 2>/dev/null; then
+  echo "Key already present on host for ${USER}"
+else
+  echo "$KEY" >> "$HOST_AUTHKEYS"
+  chown "${USER}:" "$HOST_AUTHKEYS"
+  chmod 600 "$HOST_AUTHKEYS"
+  echo "Added key to host: ${HOST_AUTHKEYS}"
+fi
+
+# --- add to container ---
+STATE=$(lxc-info -n "$CONTAINER" -sH 2>/dev/null || true)
+if [[ "$STATE" == "RUNNING" ]]; then
+  echo "$KEY" | lxc-attach --clear-env -n "$CONTAINER" -- /bin/bash -c "
+    export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+    mkdir -p /root/.ssh && chmod 700 /root/.ssh
+    KEY=\$(cat)
+    if grep -qF \"\$KEY\" /root/.ssh/authorized_keys 2>/dev/null; then
+      echo 'Key already present in container'
+    else
+      echo \"\$KEY\" >> /root/.ssh/authorized_keys
+      chmod 600 /root/.ssh/authorized_keys
+      echo 'Added key to container'
+    fi
+  "
+else
+  # container stopped — write directly into rootfs
+  ROOTFS="/var/lib/lxc/${CONTAINER}/rootfs"
+  CONT_AUTHKEYS="${ROOTFS}/root/.ssh/authorized_keys"
+  mkdir -p "${ROOTFS}/root/.ssh"
+  chmod 700 "${ROOTFS}/root/.ssh"
+  if grep -qF "$KEY" "$CONT_AUTHKEYS" 2>/dev/null; then
+    echo "Key already present in container rootfs"
+  else
+    echo "$KEY" >> "$CONT_AUTHKEYS"
+    chmod 600 "$CONT_AUTHKEYS"
+    echo "Added key to container rootfs: ${CONT_AUTHKEYS}"
+  fi
+fi
+
+echo "Done."

home/scripts/lxc/lab-mount.sh

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+#!/usr/bin/env bash
+set -euo pipefail
+
+usage() {
+  cat <<EOF
+Usage: lab-mount <container|user> <host-path> [container-path]
+
+Bind-mounts a host directory into an LXC container, persisting across reboots.
+If container-path is omitted, it mirrors host-path inside the container.
+
+Examples:
+  lab-mount alice /mnt/nas/shared              # -> /mnt/nas/shared inside lxc-alice
+  lab-mount alice /mnt/nas/shared /data/shared  # -> /data/shared inside lxc-alice
+  lab-mount lxc-alice /mnt/nas/shared           # container name directly also works
+
+To mount for ALL containers:
+  lab-mount --all /mnt/nas/shared /data/shared
+EOF
+  exit 1
+}
+
+mount_into() {
+  local CONTAINER="$1"
+  local HOST_PATH="$2"
+  local CONT_PATH="$3"
+  local ROOTFS="/var/lib/lxc/${CONTAINER}/rootfs"
+  local CONFIG="/var/lib/lxc/${CONTAINER}/config"
+
+  if [[ ! -d "$ROOTFS" ]]; then
+    echo "ERROR: container '$CONTAINER' not found" >&2
+    return 1
+  fi
+
+  if [[ ! -e "$HOST_PATH" ]]; then
+    echo "ERROR: host path '$HOST_PATH' does not exist" >&2
+    return 1
+  fi
+
+  # create mountpoint inside rootfs
+  mkdir -p "${ROOTFS}${CONT_PATH}"
+
+  # check if this bind mount is already in config
+  local ENTRY="lxc.mount.entry = ${HOST_PATH} ${CONT_PATH#/} none bind,create=dir 0 0"
+  if grep -qF "$ENTRY" "$CONFIG" 2>/dev/null; then
+    echo "Already configured: ${CONTAINER} ${HOST_PATH} -> ${CONT_PATH}"
+    return 0
+  fi
+
+  # add persistent bind mount to container config
+  echo "$ENTRY" >> "$CONFIG"
+  echo "Added to config: ${CONTAINER} ${HOST_PATH} -> ${CONT_PATH}"
+
+  # if the container is running, also mount it live
+  local STATE
+  STATE=$(lxc-info -n "$CONTAINER" -sH 2>/dev/null || true)
+  if [[ "$STATE" == "RUNNING" ]]; then
+    # lxc-attach to mount from inside
+    lxc-attach --clear-env -n "$CONTAINER" -- /bin/bash -c "
+      export PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+      mkdir -p '${CONT_PATH}'
+    "
+    # note: live bind mounts into running unprivileged containers via config
+    # may require a container restart to take effect
+    echo "NOTE: restart the container for the mount to take effect:"
+    echo "  lxc-stop -n ${CONTAINER} && lxc-start -n ${CONTAINER}"
+  fi
+}
+
+resolve_container() {
+  local NAME="$1"
+  # if it already starts with lxc-, use as-is
+  if [[ "$NAME" == lxc-* ]]; then
+    echo "$NAME"
+  elif [[ -f "/home/${NAME}/.lxc-container" ]]; then
+    cat "/home/${NAME}/.lxc-container"
+  else
+    echo "lxc-${NAME}"
+  fi
+}
+
+# --- parse args ---
+[[ $# -lt 2 ]] && usage
+
+if [[ "$1" == "--all" ]]; then
+  HOST_PATH="$2"
+  CONT_PATH="${3:-$HOST_PATH}"
+  for dir in /var/lib/lxc/lxc-*/; do
+    CONTAINER=$(basename "$dir")
+    mount_into "$CONTAINER" "$HOST_PATH" "$CONT_PATH"
+  done
+else
+  CONTAINER=$(resolve_container "$1")
+  HOST_PATH="$2"
+  CONT_PATH="${3:-$HOST_PATH}"
+  mount_into "$CONTAINER" "$HOST_PATH" "$CONT_PATH"
+fi