Terminal-first Dev Container launcher for SSH/tmux workflows. Wraps devcontainer CLI with profile selection, shell/exec/rebuild helpers, SSH agent forwarding, and Tailscale Serve/Funnel shortcuts.

devx.bash

#!/usr/bin/env bash
set -euo pipefail

cmd="${1:-shell}"
shift || true

DEVX_FORWARD_SSH_AGENT="${DEVX_FORWARD_SSH_AGENT:-1}"
DEVX_DEBUG="${DEVX_DEBUG:-0}"

DEVX_UP_ARGS=()
DEVX_EXEC_ENV=(
  "LANG=C.UTF-8"
  "LC_ALL=C.UTF-8"
  "LC_CTYPE=C.UTF-8"
)
DEVX_AGENT_DIR=""
DEVX_AGENT_SOCK=""
DEVX_AGENT_PID=""

log() {
  echo "devx: $*" >&2
}

debug() {
  if [[ "$DEVX_DEBUG" == "1" ]]; then
    echo "devx debug: $*" >&2
  fi
}

die() {
  echo "devx: $*" >&2
  exit 1
}

require_command() {
  command -v "$1" >/dev/null 2>&1 || die "$1 が見つかりません"
}

find_workspace() {
  local dir="$PWD"

  while [[ "$dir" != "/" ]]; do
    if [[ -f "$dir/devcontainer.json" ]]; then
      printf '%s\n' "$dir"
      return 0
    fi

    if [[ -f "$dir/.devcontainer/devcontainer.json" ]]; then
      printf '%s\n' "$dir"
      return 0
    fi

    if [[ -d "$dir/.devcontainer" ]]; then
      if find "$dir/.devcontainer" -mindepth 2 -maxdepth 2 -name devcontainer.json -print -quit | grep -q .; then
        printf '%s\n' "$dir"
        return 0
      fi
    fi

    dir="$(dirname "$dir")"
  done

  die "devcontainer configuration が見つかりません: $PWD"
}

workspace="$(find_workspace)"

list_configs() {
  local found=0

  if [[ -f "$workspace/devcontainer.json" ]]; then
    printf 'root\t%s\n' "$workspace/devcontainer.json"
    found=1
  fi

  if [[ -f "$workspace/.devcontainer/devcontainer.json" ]]; then
    printf 'default\t%s\n' "$workspace/.devcontainer/devcontainer.json"
    found=1
  fi

  if [[ -d "$workspace/.devcontainer" ]]; then
    while IFS= read -r file; do
      local parent
      parent="$(basename "$(dirname "$file")")"

      if [[ "$file" == "$workspace/.devcontainer/devcontainer.json" ]]; then
        continue
      fi

      printf '%s\t%s\n' "$parent" "$file"
      found=1
    done < <(find "$workspace/.devcontainer" -mindepth 2 -maxdepth 2 -name devcontainer.json | sort)
  fi

  [[ "$found" -eq 1 ]]
}

select_config() {
  local requested="${1:-}"

  local configs
  configs="$(list_configs)" || die "devcontainer.json が見つかりません: $workspace"

  if [[ -n "$requested" ]]; then
    local matched
    matched="$(printf '%s\n' "$configs" | awk -F '\t' -v name="$requested" '$1 == name { print $2 }')"

    if [[ -z "$matched" ]]; then
      echo "利用可能な devcontainer:" >&2
      printf '%s\n' "$configs" | awk -F '\t' '{ print "  " $1 }' >&2
      die "指定された devcontainer が見つかりません: $requested"
    fi

    printf '%s\n' "$matched"
    return 0
  fi

  local count
  count="$(printf '%s\n' "$configs" | wc -l | tr -d ' ')"

  if [[ "$count" -eq 1 ]]; then
    printf '%s\n' "$configs" | awk -F '\t' '{ print $2 }'
    return 0
  fi

  if command -v fzf >/dev/null 2>&1; then
    printf '%s\n' "$configs" \
      | fzf --prompt='devcontainer> ' --with-nth=1 \
      | awk -F '\t' '{ print $2 }'
    return 0
  fi

  echo "複数の devcontainer があります。名前を指定してください:" >&2
  printf '%s\n' "$configs" | awk -F '\t' '{ print "  " $1 }' >&2
  die "例: devx shell backend-api"
}

config_name_from_path() {
  local config="$1"

  if [[ "$config" == "$workspace/devcontainer.json" ]]; then
    echo "root"
  elif [[ "$config" == "$workspace/.devcontainer/devcontainer.json" ]]; then
    echo "default"
  else
    basename "$(dirname "$config")"
  fi
}

hash_for_config() {
  local config="$1"
  local name
  name="$(printf '%s' "${workspace}:${config}" | sha1sum | awk '{ print $1 }' | cut -c1-12)"
  printf '%s\n' "$name"
}

ensure_devcontainer_mount_supported() {
  if ! devcontainer up --help 2>&1 | grep -q -- '--mount'; then
    die "この devcontainer CLI は 'devcontainer up --mount' に対応していないようです。devcontainer CLI の更新が必要です。"
  fi
}

setup_ssh_agent_forwarding() {
  local config="$1"

  DEVX_UP_ARGS=()
  DEVX_EXEC_ENV=(
    "LANG=C.UTF-8"
    "LC_ALL=C.UTF-8"
    "LC_CTYPE=C.UTF-8"
  )

  if [[ "$DEVX_FORWARD_SSH_AGENT" != "1" ]]; then
    debug "SSH agent forwarding disabled"
    return 0
  fi

  if [[ -z "${SSH_AUTH_SOCK:-}" ]]; then
    log "SSH_AUTH_SOCK がないため SSH agent forwarding は無効です"
    return 0
  fi

  if [[ ! -S "${SSH_AUTH_SOCK:-}" ]]; then
    log "SSH_AUTH_SOCK が socket ではないため SSH agent forwarding は無効です: ${SSH_AUTH_SOCK}"
    return 0
  fi

  require_command socat
  ensure_devcontainer_mount_supported

  local uid
  uid="$(id -u)"

  local key
  key="$(hash_for_config "$config")"

  DEVX_AGENT_DIR="/tmp/devx-ssh-agent-${uid}"
  DEVX_AGENT_SOCK="${DEVX_AGENT_DIR}/agent-${key}.sock"
  DEVX_AGENT_PID="${DEVX_AGENT_DIR}/agent-${key}.pid"

  mkdir -p "$DEVX_AGENT_DIR"
  chmod 700 "$DEVX_AGENT_DIR"

  if [[ -f "$DEVX_AGENT_PID" ]]; then
    local old_pid
    old_pid="$(cat "$DEVX_AGENT_PID" 2>/dev/null || true)"

    if [[ -n "$old_pid" ]] && kill -0 "$old_pid" 2>/dev/null; then
      debug "kill old socat pid: $old_pid"
      kill "$old_pid" 2>/dev/null || true
    fi
  fi

  rm -f "$DEVX_AGENT_SOCK"

  debug "start socat relay: ${DEVX_AGENT_SOCK} -> ${SSH_AUTH_SOCK}"

  socat \
    "UNIX-LISTEN:${DEVX_AGENT_SOCK},fork,mode=0600" \
    "UNIX-CONNECT:${SSH_AUTH_SOCK}" \
    >/dev/null 2>&1 &

  echo "$!" > "$DEVX_AGENT_PID"

  # socket 作成を少し待つ
  local i
  for i in {1..20}; do
    if [[ -S "$DEVX_AGENT_SOCK" ]]; then
      break
    fi
    sleep 0.05
  done

  if [[ ! -S "$DEVX_AGENT_SOCK" ]]; then
    die "socat relay socket を作成できませんでした: $DEVX_AGENT_SOCK"
  fi

  # socket 自体ではなく、親ディレクトリを mount する。
  # これにより、同じ path の socket を作り直しても container 側から見える。
  DEVX_UP_ARGS+=(
    --mount "type=bind,source=${DEVX_AGENT_DIR},target=${DEVX_AGENT_DIR}"
  )

  DEVX_EXEC_ENV+=(
    "SSH_AUTH_SOCK=${DEVX_AGENT_SOCK}"
  )

  debug "mount arg: --mount type=bind,source=${DEVX_AGENT_DIR},target=${DEVX_AGENT_DIR}"
  debug "container SSH_AUTH_SOCK: ${DEVX_AGENT_SOCK}"
}

run_devcontainer_up() {
  local config="$1"
  shift || true

  debug "devcontainer up --workspace-folder $workspace --config $config ${DEVX_UP_ARGS[*]} $*"

  devcontainer up \
    --workspace-folder "$workspace" \
    --config "$config" \
    "${DEVX_UP_ARGS[@]}" \
    "$@"
}

run_devcontainer_exec() {
  local config="$1"
  shift

  local env_cmd=(env)
  local e
  for e in "${DEVX_EXEC_ENV[@]}"; do
    env_cmd+=("$e")
  done

  debug "devcontainer exec --workspace-folder $workspace --config $config ${env_cmd[*]} $*"

  devcontainer exec \
    --workspace-folder "$workspace" \
    --config "$config" \
    "${env_cmd[@]}" \
    "$@"
}

enter_default_shell() {
  local config="$1"

  run_devcontainer_exec "$config" sh -lc '
    if command -v zsh >/dev/null 2>&1; then
      exec zsh -l
    elif command -v bash >/dev/null 2>&1; then
      exec bash -l
    else
      exec sh -l
    fi
  '
}

show_doctor() {
  echo "workspace: $workspace"
  echo

  echo "configs:"
  list_configs | awk -F '\t' '{ print "  " $1 " -> " $2 }'
  echo

  echo "host:"
  echo "  user: $(id -un)"
  echo "  uid: $(id -u)"
  echo "  SSH_AUTH_SOCK: ${SSH_AUTH_SOCK:-}"
  if [[ -n "${SSH_AUTH_SOCK:-}" && -S "${SSH_AUTH_SOCK:-}" ]]; then
    echo "  SSH_AUTH_SOCK exists: yes"
  else
    echo "  SSH_AUTH_SOCK exists: no"
  fi
  echo

  echo "commands:"
  if command -v devcontainer >/dev/null 2>&1; then
    echo "  devcontainer: $(command -v devcontainer)"
    if devcontainer up --help 2>&1 | grep -q -- '--mount'; then
      echo "  devcontainer up --mount: yes"
    else
      echo "  devcontainer up --mount: no"
    fi
  else
    echo "  devcontainer: missing"
  fi

  if command -v socat >/dev/null 2>&1; then
    echo "  socat: $(command -v socat)"
  else
    echo "  socat: missing"
  fi

  if command -v jq >/dev/null 2>&1; then
    echo "  jq: $(command -v jq)"
  else
    echo "  jq: missing"
  fi

  if command -v fzf >/dev/null 2>&1; then
    echo "  fzf: $(command -v fzf)"
  else
    echo "  fzf: missing"
  fi
}

require_command devcontainer

case "$cmd" in
  list|ls)
    list_configs | awk -F '\t' '{ print $1 }'
    ;;

  path)
    echo "$workspace"
    ;;

  config)
    profile="${1:-}"
    config="$(select_config "$profile")"
    echo "$config"
    ;;

  doctor)
    show_doctor
    ;;

  up)
    profile="${1:-}"
    config="$(select_config "$profile")"
    setup_ssh_agent_forwarding "$config"

    log "up $(config_name_from_path "$config")"
    run_devcontainer_up "$config"
    ;;

  rebuild)
    profile="${1:-}"
    config="$(select_config "$profile")"
    setup_ssh_agent_forwarding "$config"

    log "rebuild $(config_name_from_path "$config")"
    run_devcontainer_up "$config" --remove-existing-container
    ;;

  shell|sh)
    profile="${1:-}"
    config="$(select_config "$profile")"
    setup_ssh_agent_forwarding "$config"

    log "shell $(config_name_from_path "$config")"
    run_devcontainer_up "$config"
    enter_default_shell "$config"
    ;;

  exec)
    profile="${1:-}"
    [[ -n "$profile" ]] || die "usage: devx exec <profile> -- <command...>"
    shift || true

    if [[ "${1:-}" == "--" ]]; then
      shift
    fi

    [[ "$#" -gt 0 ]] || die "usage: devx exec <profile> -- <command...>"

    config="$(select_config "$profile")"
    setup_ssh_agent_forwarding "$config"

    run_devcontainer_up "$config"
    run_devcontainer_exec "$config" "$@"
    ;;

  serve)
    port="${1:-18000}"
    tailscale serve "localhost:${port}"
    ;;

  serve-off)
    tailscale serve off
    ;;

  funnel)
    port="${1:-18000}"
    tailscale funnel "localhost:${port}"
    ;;

  funnel-off)
    tailscale funnel off
    ;;

  url)
    require_command jq
    host="$(tailscale status --json | jq -r '.Self.DNSName // empty' | sed 's/\.$//')"
    [[ -n "$host" ]] || die "Tailscale DNSName を取得できませんでした"
    echo "https://${host}"
    ;;

  *)
    cat >&2 <<EOF
usage:
  devx list
  devx path
  devx config [profile]
  devx doctor
  devx up [profile]
  devx rebuild [profile]
  devx shell [profile]
  devx exec <profile> -- <command...>
  devx serve [host_port]
  devx serve-off
  devx funnel [host_port]
  devx funnel-off
  devx url

examples:
  devx shell backend-api
  devx shell client-app
  devx exec backend-api -- ssh-add -L
  DEVX_DEBUG=1 devx rebuild backend-api
  DEVX_FORWARD_SSH_AGENT=0 devx shell backend-api
EOF
    exit 2
    ;;
esac