任意のWiFi接続・切断時に任意のシェルスクリプトを実行するHammerspoonの設定

config.json

{
    "base": {
        "notify": false,
        "shell": "/bin/bash",
        "with_user_env": true
    },
    "networks": [
        {
            "SSID": "ssid1",
            "profile": "proxy",
            "pre_hook": "hoge.sh",
            "post_hook": "fuga.sh"
        },
        {
            "SSID": "ssid2",
            "pre_hook": "poyo.sh",
            "post_hook": "piyo.sh"
        }
    ]
}

init.lua

-- init
HOME = os.getenv("HOME")
CONFIG_HOME = HOME .. "/.hammerspoon/"
CONFIG_FILE = CONFIG_HOME .. "config.json"
SCRIPTS_PATH = CONFIG_HOME .. "Scripts/"
PROFILE_CHANGE_SCRIPT = SCRIPTS_PATH .. "nw_profile_changer.sh"

-- key
NETWORKS_KEY = "networks"
SHELL_KEY = "shell"
BASE_CONFIG_KEY = "base"
NOTIFY_KEY = "notify"
USER_ENV_KEY = "with_user_env"
SSID_KEY = "SSID"
PROFILE_KEY = "profile"
PRE_HOOK_KEY = "pre_hook"
POST_HOOK_KEY = "post_hook"

-- default settings
NOTIFY = true
SHELL = "/bin/bash"
USER_ENV = true
DEFAULT_NW_PROFILE = "Automatic"

-- tmp
prevSSID = hs.wifi.currentNetwork()

function hasKey(tbl, key)
    for k, v in pairs (tbl) do
        if k == key then 
            return true 
        end
    end
    return false
end

function readConfig(files)
    -- jsonファイルを開いて一行ずつ読み出し，decode
    local fp = io.open(files[1], "r")
    local json = fp:read("*a")
    fp:close()
    local config = hs.json.decode(json)
    if hasKey(config, BASE_CONFIG_KEY) then
        for k, v in pairs(config[BASE_CONFIG_KEY]) do
            hs.settings.set(k, v)
        end
    end
    -- Default valueをセット
    if not hasKey(config, NOTIFY_KEY) then
        hs.settings.set(NOTIFY_KEY, NOTIFY)
    end
    if not hasKey(config, SHELL_KEY) then
        hs.settings.set(SHELL_KEY, SHELL)
    end
    if not hasKey(config, USER_ENV_KEY) then
        hs.settings.set(USER_ENV_KEY, USER_ENV)
    end
    -- Networkプロファイルをロード
    if hasKey(config, NETWORKS_KEY) then
        hs.settings.set(NETWORKS_KEY, config[NETWORKS_KEY])
    end
    if hs.settings.get(NOTIFY_KEY) then
        local notify_msg = string.format("display notification \"Reloaded\" with title \"WLAN Profiles\"")
        hs.osascript.applescript(notify_msg)
    end
end

function execHook(path)
    if path then
        local script = SCRIPTS_PATH .. path
        local shell = hs.settings.get(SHELL_KEY)
        local with_user_env = hs.settings.get(USER_ENV_KEY) 
        hs.execute(shell .. " " .. script, with_user_env)
    end
end

function loadNwProfile(profile_name)
    -- ネットワーク環境の切り替え
    local command = nil
    local shell = hs.settings.get(SHELL_KEY)
    local with_user_env = hs.settings.get(USER_ENV_KEY)  
    if profile_name then
        command = shell .. " " .. PROFILE_CHANGE_SCRIPT .. " " .. profile_name
    else
        command = shell .. " " .. PROFILE_CHANGE_SCRIPT .. " " .. DEFAULT_NW_PROFILE
    end
    hs.execute(command, with_user_envi)
end

function nwProfileChanger(ssid, profile, connection)
    if connection then
        -- hookの実行
        loadNwProfile(profile[PROFILE_KEY])
        if hasKey(profile, PRE_HOOK_KEY) then
            execHook(profile[PRE_HOOK_KEY])
        end
    else
        if hasKey(profile, POST_HOOK_KEY) then
            execHook(profile[POST_HOOK_KEY])
        end
    end
end

function ssidChangedCallback(watcher, msg, interface)
    local newSSID = hs.wifi.currentNetwork()
    if prevSSID ~= newSSID then
        for i, nw in ipairs(hs.settings.get(NETWORKS_KEY)) do
            if not prevSSID and newSSID and nw[SSID_KEY] == newSSID then
                -- 接続時
                nwProfileChanger(newSSID, nw, true)
                break
            elseif prevSSID and not newSSID and nw[SSID_KEY] == prevSSID then
                -- 切断時
                nwProfileChanger(prevSSID, nw, false)
                break
            end 
        end
    end
    prevSSID = newSSID
end

-- exec
readConfig({CONFIG_FILE})
hs.pathwatcher.new(CONFIG_FILE, readConfig):start()
hs.wifi.watcher.new(ssidChangedCallback):start()

nw_profile_changer.sh

currentlocation=`networksetup -getcurrentlocation`

if test $currentlocation = $1; then
    return
fi
scselect `scselect | grep ${1} | cut -b 4-40`