【air】/app/tmpmain.exe: not foundの解決方法【Golang】

こんにちはRujuuです。

今回は「/app/tmpmain.exe: not found」の解決方法を紹介します。

発生経緯
環境
解決方法
- 変更前
- 変更後
おわりに

発生経緯

Echoでバックエンドの開発をしていて、ホットリロードを行うためにairを導入したところ以下の様な「/app/tmpmain.exe: not found」エラーが出ました。

環境

Docker Desktop 4.10.1
Go 1.20.4
Echo v4.10.2
air 1.43.0 https://github.com/cosmtrek/air/releases/tag/v1.43.0

必要ないかもしれませんが、Dockerfileとdocker-compose.ymlのコードも載せておきます。

Dockerfile

FROM golang:1.20-bullseye

ENV TZ /usr/share/zoneinfo/Asia/Tokyo

WORKDIR /app

RUN apt-get update && apt-get install -y tree vim

RUN go install github.com/cosmtrek/air@latest

COPY go.mod go.sum ./
RUN go mod download && go mod verify

docker-compose.yml

version: "3.8"

services:
  echo:
    container_name: echo
    build: .
    volumes:
      - .:/app
    tty: true
    ports:
      - "8080:8080"
    networks:
      - backend

  postgres:
    image: postgres:15.1-alpine
    ports:
      - 5432:5432
    environment:
      POSTGRES_USER: test
      POSTGRES_PASSWORD: test
      POSTGRES_DB: test
    restart: always
    networks:
      - backend

networks:
  backend:

解決方法

「air init」で生成される「.air.toml」のbinのpathを書き換えると正常に動きます。

以下のコードでいうと7行目です。

変更前

.air.toml

root = "."
testdata_dir = "testdata"
tmp_dir = "tmp"

[build]
  args_bin = []
  bin = "tmp\\main.exe"
  cmd = "go build -o ./tmp/main.exe ."
  delay = 0
  exclude_dir = ["assets", "tmp", "vendor", "testdata"]
  exclude_file = []
  exclude_regex = ["_test.go"]
  exclude_unchanged = false
  follow_symlink = false
  full_bin = ""
  include_dir = []
  include_ext = ["go", "tpl", "tmpl", "html"]
  include_file = []
  kill_delay = "0s"
  log = "build-errors.log"
  poll = false
  poll_interval = 0
  rerun = false
  rerun_delay = 500
  send_interrupt = false
  stop_on_error = false

[color]
  app = ""
  build = "yellow"
  main = "magenta"
  runner = "green"
  watcher = "cyan"

[log]
  main_only = false
  time = false

[misc]
  clean_on_exit = false

[screen]
  clear_on_rebuild = false
  keep_scroll = true

変更後

.air.toml

root = "."
testdata_dir = "testdata"
tmp_dir = "tmp"

[build]
  args_bin = []
  bin = "./tmp/main.exe"
  cmd = "go build -o ./tmp/main.exe ."
  delay = 0
  exclude_dir = ["assets", "tmp", "vendor", "testdata"]
  exclude_file = []
  exclude_regex = ["_test.go"]
  exclude_unchanged = false
  follow_symlink = false
  full_bin = ""
  include_dir = []
  include_ext = ["go", "tpl", "tmpl", "html"]
  include_file = []
  kill_delay = "0s"
  log = "build-errors.log"
  poll = false
  poll_interval = 0
  rerun = false
  rerun_delay = 500
  send_interrupt = false
  stop_on_error = false

[color]
  app = ""
  build = "yellow"
  main = "magenta"
  runner = "green"
  watcher = "cyan"

[log]
  main_only = false
  time = false

[misc]
  clean_on_exit = false

[screen]
  clear_on_rebuild = false
  keep_scroll = true

これで以下のように、airが正常に動くようになったと思います！