Question

以下片段将一次选择一个服务器。有没有办法立刻击中它们？

upstream backend {
    server 17.0.0.1:8000;
    server 17.0.0.1:8001;
    server 17.0.0.1:8002;
    server 17.0.0.1:8003;

}

server {
    location / {
        proxy_pass http://backend;
    }
}

Answer 1

我今天遇到了类似的情况，想要对我的许多服务器广播一个GET，这些服务器正在监听API以触发git pulls。我在Nginx中找不到任何处理这种行为的东西，我不想跳到编写扩展名。

相反，我使用Python的Flask和Requests模块将一些东西混在一起：

from flask import Flask, jsonify, request
import requests

app = Flask(__name__)

# add whatever you need here to the methods
@app.route("/http/replay/<method>", methods=["POST", "GET", "PUT", "OPTIONS"])
def http_replay(method):
    """Replay an incoming request of type <method> against the parameter list of endpoints"""

    endpoint_list = request.args.get("host", "")
    endpoint_list = endpoint_list.split(";")
    timeout = request.args.get("timeout", None) or 5

    if not endpoint_list:
        return jsonify(status=500,
                       message="Expected parameters in the form of ?host=http://host/path;host=http://host2/path")
    else:

        responses = []
        for ep in endpoint_list:
            try:
                _r = requests.__getattribute__(method.lower())(ep, timeout=timeout)

                status_code = _r.status_code
            except requests.exceptions.Timeout:
                status_code = 408  # request timeout
            except requests.exceptions.RequestException:
                status_code = 520

            responses.append(status_code)

        _r_status = set(responses)

        if len(_r_status) == 1 and _r_status.pop == 200:
            status = 200
        else:
            status = 520

        return jsonify(status=status)

这只是监听路径并允许我发送请求，例如：

curl "http://localhost:5000/plugins/http/replay/POST?host=http://localhost:80/api;host=http://dev.localhost:8080/api?timeout=10"

并且如果URL参数中的所有端点都相同，则返回HTTP 200状态代码。

Answer 2

如果您是通过Lua模块构建了nginx（或者您正在使用OpenResty），则以下代码段将允许您将响应广播到上游组中的所有服务器。

请求是并行进行的，完成后，将返回单独的HTTP响应和响应头。

upstream @api {
    server  10.0.0.1:80;
    server  10.0.0.2:80 backup;
}

server {
    server_name _;
    listen 443 ssl;

    location ~ ^/broadcast(?<proxy_path>/.*)$ {
        lua_need_request_body on;

        content_by_lua '
            local upstream = require "ngx.upstream"
            local servers = upstream.get_servers("@api")

            local requests = {}
            for _, srv in ipairs(servers) do
                local addr = srv.addr
                table.insert(requests, { "/proxy", { method = ngx["HTTP_" .. ngx.var.request_method], always_forward_body = true, copy_all_vars = true, vars = { proxy_host = addr } } })
            end

            local responses = { ngx.location.capture_multi(requests) }
            for i, res in ipairs(responses) do
                local addr = servers[i].addr
                ngx.say(addr, " HTTP/1.1 ", res.status)
                for header, value in pairs(res.header) do
                    ngx.say(header, ": ", value)
                end
                ngx.say()
                ngx.print(res.body)
                ngx.say()
            end
        ';
    }

    location /proxy {
        internal;
        proxy_pass http://$proxy_host$proxy_path$is_args$args;
    }

}

Answer 3

以下是使用ngx_http_mirror_module的解决方案（自nginx 1.13.4起可用）：

server {
    location / {
        proxy_pass http://17.0.0.1:8000;
        mirror /s1;
        mirror /s2;
        mirror /s3;       
    }
    location /s1 { internal; proxy_pass http://17.0.0.1:8001$request_uri; }
    location /s2 { internal; proxy_pass http://17.0.0.1:8002$request_uri; }
    location /s3 { internal; proxy_pass http://17.0.0.1:8003$request_uri; }
}

nginx将：

向所有服务器发送相同的请求
等待他们全部完成
回复http://17.0.0.1:8000（并忽略其他回复）

有没有办法配置Nginx同时向多个上游服务器广播传入请求？

3 个答案: