使用 Docker compose 搭建 wlua 开发环境

[hanxi]

仿造这里的： https://docs.docker.com/compose/gettingstarted/

前置要求

You need to have Docker Engine and Docker Compose on your machine. You can either:

• Install Docker Engine and Docker Compose as standalone binaries
• Install Docker Desktop which includes both Docker Engine and Docker Compose

第 1 步：写段 wlua 代码

1. 创建一个工程目录：

$ mkdir composetest
$ cd composetest

2. 在工程目录下新键文件 main.lua ，代码如下：

local wlua = require "wlua"
local redis = require "skynet.db.redis"

local g_db
local function getdb()
    if g_db then return g_db end
    local conf = { host = "redis", port = 6379, db = 0, }
    g_db = redis.connect(conf)
    return g_db
end

local app = wlua:default()
app:get("/", function (c)
    local db = getdb()
    local count = db:incr("hits")
    c:send(string.format("Hello World! I have been seen %d times.\n", count))
end)

app:run()

在这个例子中， "redis" 是 redis 容器的网络名字，我们使用的默认的 Redis 端口 6379 和默认的数据库 0 。

第 2 步：创建一个 Dockerfile 文件

Dockerfile 用于构建一个 Docker 镜像，在你的 composetest 目录创建一个名为 Dockerfile 的文件，内容如下：

FROM hanxi/wlua
RUN cd / && wlua new code
WORKDIR /code
EXPOSE 8081
CMD [ "bash", "-c", "wlua start && tail -F log/wlua.log" ]

这几行告诉 Docker 干这些事：

• 从镜像 hanxi/wlua 的基础上构建一个新的镜像。
• 在根目录执行 wlua new code 命令，用于创建 /code 工程目录。
• 设置工作目录为 /code 。
• 在镜像中添加元数据来描述容器正在监听 8081 端口。
• 使用 bash 执行命令：启动 wlua 和输出日志。

第 3 步：在 Compose 文件中定义服务

在 composetest 目录创建名为 docker-compose.yml 的文件，内容如下：

version: "3.9"
services:
  web:
    build: .
    ports:
      - "8000:8081"
    volumes:
      - ./main.lua:/code/app/main.lua
  redis:
    image: "redis:alpine"

这个 Compose 文件定义了 2个服务： web 和 redis 。

web 服务使用从当前目录中的 Dockerfile 构建的镜像。然后它将容器和主机绑定到公开的端口 8000。此示例服务使用 wlua Web 服务器的默认端口 8081。 还挂载了主机的 main.lua 文件到容器中。

redis 服务使用从 Docker Hub 镜像仓库中提取的公共 Redis 镜像。

第 4 步：使用 Compose 构建并运行您的应用

1. 在你的 composetest 目录执行命令 docker compose up ：

$ docker compose up
Creating network "composetest_default" with the default driver
Creating composetest_web_1   ... done
Creating composetest_redis_1 ... done
Attaching to composetest_redis_1, composetest_web_1
redis_1  | 1:C 07 Jan 2023 07:29:35.235 # oO0OoO0OoO0Oo Redis is starting oO0OoO0OoO0Oo
redis_1  | 1:C 07 Jan 2023 07:29:35.235 # Redis version=7.0.7, bits=64, commit=00000000, modified=0, pid=1, just started
redis_1  | 1:C 07 Jan 2023 07:29:35.235 # Warning: no config file specified, using the default config. In order to specify a config file use redis-server /path/to/redis.conf
redis_1  | 1:M 07 Jan 2023 07:29:35.236 * monotonic clock: POSIX clock_gettime
redis_1  | 1:M 07 Jan 2023 07:29:35.236 * Running mode=standalone, port=6379.
redis_1  | 1:M 07 Jan 2023 07:29:35.236 # Server initialized
redis_1  | 1:M 07 Jan 2023 07:29:35.236 # WARNING Memory overcommit must be enabled! Without it, a background save or replication may fail under low memory condition. Being disabled, it can can also cause failures without low memory condition, see https://github.com/jemalloc/jemalloc/issues/1328. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.
redis_1  | 1:M 07 Jan 2023 07:29:35.237 * Ready to accept connections
web_1    | start server
web_1    | tail: cannot open 'log/wlua.log' for reading: No such file or directory
web_1    | tail: 'log/wlua.log' has appeared;  following new file
web_1    | [0000000a][2023-01-07 07:29:36] LAUNCH snlua main
web_1    | [0000000b][2023-01-07 07:29:36] LAUNCH snlua app/main http 1
web_1    | [0000000b][2023-01-07 07:29:36] [DEBUG] wlua new.
web_1    | [0000000b][2023-01-07 07:29:36] [DEBUG] routergroup new
web_1    | [0000000b][2023-01-07 07:29:36] [DEBUG] combine_handlers. n: 1
web_1    | [0000000b][2023-01-07 07:29:36] [DEBUG] calculate_absolute_path / /
web_1    | [0000000b][2023-01-07 07:29:36] [DEBUG] combine_handlers. n: 1
web_1    | [0000000b][2023-01-07 07:29:36] [DEBUG] add_route: GET / 2
web_1    | [0000000b][2023-01-07 07:29:36] [INFO] Open wlua agent. protocol: http , agent_id: 1
web_1    | [0000000a][2023-01-07 07:29:36] [INFO] Start web. host: 0.0.0.0 ,port: 8081
web_1    | [0000000a][2023-01-07 07:29:36] [WARN] Disable https server.
web_1    | [0000000a][2023-01-07 07:29:36] [INFO] Hello wlua.
web_1    | [00000002][2023-01-07 07:29:36] KILL self

2. Enter http://localhost:8000/ in a browser to see the application running.

If this doesn’t resolve, you can also try http://127.0.0.1:8000.

You should see a message in your browser saying:

Hello World! I have been seen 1 times.

3. Refresh the page.

The number should increment.

Hello World! I have been seen 2 times.

最后

composetest 工程地址： https://github.com/hanxi/docker-compose-wlua