Advanced Openresty health check for multiple backends using LUA

openresty_healthcheck.lua

access_by_lua_block {
    local http = require "resty.http"
    local h = http.new()
    h:set_timeout(2 * 1000)
    local url = "http://127.0.0.1:18086/ping"
    local res, err = h:request_uri(url, {method = "GET"})
    if err or not res or res.status ~= 204 then
        ngx.status = ngx.HTTP_SERVICE_UNAVAILABLE
        ngx.exit(ngx.HTTP_OK)
    end
    url = "http://127.0.0.1:9096/ping"
    res, err = h:request_uri(url, {method = "GET"})
    if err or not res or res.status ~= 200 then
        ngx.status = ngx.HTTP_SERVICE_UNAVAILABLE
    end
    ngx.exit(ngx.HTTP_OK)
}