ELK - nginx 日志分析及绘图

时间 2019-11-06

标签 elk nginx 日志分析绘图栏目 Nginx 繁體版

原文原文链接

1. 前言

先上一张总体的效果图：html

上面这张图就是经过 ELK 分析 nginx 日志所获得的数据，经过 kibana 的功能展现出来的效果图。是否是这样对日志作了解析，想要知道的数据一目了然。接下来就是实现过程实录。node

2. 实现过程

经过上一篇：ELK 部署文档已经对 ELK + filebeat 获取 nginx 作了详细的配置介绍，这里重点就不在安装 ELK 上面了。下面这边的内容，主要是针对 logstash 配置文件的编写和 kibana web界面的配置。nginx

主机信息在申明下，和上一篇同样：web

2.1 nginx 日志格式编写

在编写logstash 文件以前，得有一个标准输入输出格式，这个格式通用的就是 json 格式。正则表达式

首先，考虑如何才能获取 json 格式的日志，固然能够直接经过修改 nginx 日志的格式来实现，所以开始修改 nginx 日志格式。若是获取的日志没法修改json 格式，则能够经过正则表达式来匹配。

json

在nginx 配置文件中添加以下日志格式：vim

http {
…
    log_format main_json '{"domain":"$server_name",'
    '"http_x_forwarded_for":"$http_x_forwarded_for",'
    '"time_local":"$time_iso8601",'
    '"request":"$request",'
    '"request_body":"$request_body",'
    '"status":$status,'
    '"body_bytes_sent":"$body_bytes_sent",'
    '"http_referer":"$http_referer",'
    '"upstream_response_time":"$upstream_response_time",'
    '"request_time":"$request_time",'
    '"http_user_agent":"$http_user_agent",'
    '"upstream_addr":"$upstream_addr",'
    '"upstream_status":"$upstream_status"}';


….
}

定义的这个nginx 日志格式叫 main_json 后面的配置文件，均可以引用这个日志格式。除了nginx 日志参数之外，还能够经过配置文件来自行添加自定义参数，好比获取用户的真实ip后端

因而编写一个自定义变量的配置文件：centos

[root@192.168.118.16 ~]#vim /etc/nginx/location.conf

#set $real_ip $remote_addr;
if ( $http_x_forwarded_for ~ "^(\d+\.\d+\.\d+\.\d+)" ) {
        set $real_ip $1;
}

这个配置文件只是为了获取用户的真实IP，变量名为： real_ip 须要在nginx.conf 中引用，在刚才的配置文件中也加入该变量，完整日志格式以下：浏览器

    log_format main_json '{"domain":"$server_name",'
    '"real_ip":"$real_ip",'
    '"http_x_forwarded_for":"$http_x_forwarded_for",'
    '"time_local":"$time_iso8601",'
    '"request":"$request",'
    '"request_body":"$request_body",'
    '"status":$status,'
    '"body_bytes_sent":"$body_bytes_sent",'
    '"http_referer":"$http_referer",'
    '"upstream_response_time":"$upstream_response_time",'
    '"request_time":"$request_time",'
    '"http_user_agent":"$http_user_agent",'
    '"upstream_addr":"$upstream_addr",'
    '"upstream_status":"$upstream_status"}';

注释掉该行：

#access_log  /var/log/nginx/access.log  main;

接下来，编写一个nginx 配置文件端口为 9527 做为测试使用

[root@192.168.118.16 ~]#vim /etc/nginx/conf.d/server_9527.conf
server {
    listen 9527;
    server_name localhost;
    include location.conf;
    location / {
        root /www/9527/;
        index index.html;
        access_log /www/log/access.log main_json;
        error_log /www/log/error.log;
    }
    location /shop {
        root /www/9527;
        access_log /www/log/shop_access.log main_json;
        error_log /www/log/shop_error.log;
    }
}

[root@192.168.118.16 ~]#mkdir -p /www/{9527,log}
[root@192.168.118.16 ~]#cd /www/9527/
[root@192.168.118.16 /www/9527]#vim index.html
hello, 9527
[root@192.168.118.16 /www/9527]#mkdir -pv /www/9527/shop
[root@192.168.118.16 /www/9527]#vim /www/9527/shop/index.html
出售9527

[root@192.168.118.16 /www/9527]#nginx -t
[root@192.168.118.16 /www/9527]#nginx -s reload

Nginx 配置完成，从新加载，访问测试：

[root@192.168.118.16 ~]#curl http://192.168.118.16:9527/index.html
hello, 9527
[root@192.168.118.16 ~]#curl http://192.168.118.16:9527/shop/index.html
出售9527

页面访问正常，查看日志：

[root@192.168.118.16 ~]#ll -tsh /www/log/
total 8.0K
4.0K -rw-r--r--  1 root root 346 Sep 14 14:35 shop_access.log
4.0K -rw-r--r--. 1 root root 341 Sep 14 14:35 access.log
   0 -rw-r--r--. 1 root root   0 Sep 14 14:35 error.log
   0 -rw-r--r--  1 root root   0 Sep 14 14:34 shop_error.log

日志文件已生成，查看日志格式：

[root@192.168.118.16 ~]#cat /www/log/access.log 
{"domain":"localhost","real_ip":"","http_x_forwarded_for":"-","time_local":"2019-09-14T14:35:11+08:00","request":"GET /index.html HTTP/1.1","request_body":"-","status":200,"body_bytes_sent":"12","http_referer":"-","upstream_response_time":"-","request_time":"0.000","http_user_agent":"curl/7.29.0","upstream_addr":"-","upstream_status":"-"}

定义的 json 格式已经被引用到，nginx日志格式配置完成，接下来就是经过filebeat 将nginx 日志传递给 logstash

2.2 filebeat 传输 nginx 日志

这里在上一篇的基础上作修改，直接修改 filebeat 配置文件：

[root@192.168.118.16 ~]#vim /etc/filebeat/modules.d/nginx.yml

重启 filebeat 服务

[root@192.168.118.16 ~]#systemctl restart filebeat

2.3 logstash 配置文件编写

经过上面的步骤，filebeat 已经将 nginx 日志传输过来了，接下来就看 logstash 要怎么接收日志数据了，仍是经过按部就班的方式来编写。

首先将日志数据打印到屏幕，保证数据的正确性。

从 nginx.conf 启动 logstash。经过浏览器访问 nginx 9527端口产生日志数据。

这里启动 logstash 能够添加修改自动重载的模式，这样当修改了 nginx.conf 时，没必要频繁的去关闭重启。

[root@192.168.118.15 /etc/logstash/conf.d]#logstash -f nginx.conf  --config.reload.automatic

经过抓取一段 json 数据，分析下：

{
    "@timestamp" => 2019-09-14T06:52:16.056Z,
      "@version" => "1",
        "source" => "/www/log/access.log",
         "input" => {
        "type" => "log"
    },
          "beat" => {
            "name" => "web-node1",
         "version" => "6.8.2",
        "hostname" => "web-node1"
    },
          "host" => {
                 "name" => "web-node1",
         "architecture" => "x86_64",
                   "id" => "4b3b32a1db0343458c4942a10c79acef",
                   "os" => {
                "name" => "CentOS Linux",
            "codename" => "Core",
              "family" => "redhat",
            "platform" => "centos",
             "version" => "7 (Core)"
        },
        "containerized" => false
    },
           "log" => {
        "file" => {
            "path" => "/www/log/access.log"
        }
    },
          "tags" => [
        [0] "beats_input_codec_plain_applied"
    ],
    "prospector" => {
        "type" => "log"
    },
       "fileset" => {
        "module" => "nginx",
          "name" => "access"
    },
        "offset" => 9350,
         "event" => {
        "dataset" => "nginx.access"
    },
       "message" => "{\"domain\":\"localhost\",\"real_ip\":\"\",\"http_x_forwarded_for\":\"-\",\"time_local\":\"2019-09-14T14:52:15+08:00\",\"request\":\"GET / HTTP/1.1\",\"request_body\":\"-\",\"status\":304,\"body_bytes_sent\":\"0\",\"http_referer\":\"-\",\"upstream_response_time\":\"-\",\"request_time\":\"0.000\",\"http_user_agent\":\"Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36\",\"upstream_addr\":\"-\",\"upstream_status\":\"-\"}"
}

logstash 输出内容

这里面数据不少，可是这里的有些数据不是必要的，应该保留须要的数据，而剔除不必的数据，使 json 看起来更加简洁。

首先来查看这段 json ，发现真正的 nginx 日志数据都存在 message 里面，其余的都是一些主机服务相关的信息，可是 message 看起来乱糟糟的，简直无法看。既然采用的 json 格式，那就可以格式化。

修改配置文件以下：

{
                  "@version" => "1",
                      "host" => {
                   "os" => {
                "name" => "CentOS Linux",
             "version" => "7 (Core)",
              "family" => "redhat",
            "platform" => "centos",
            "codename" => "Core"
        },
                 "name" => "web-node1",
                   "id" => "4b3b32a1db0343458c4942a10c79acef",
         "architecture" => "x86_64",
        "containerized" => false
    },
    "upstream_response_time" => "-",
                      "beat" => {
            "name" => "web-node1",
         "version" => "6.8.2",
        "hostname" => "web-node1"
    },
                    "domain" => "localhost",
              "request_body" => "-",
                       "log" => {
        "file" => {
            "path" => "/www/log/access.log"
        }
    },
           "http_user_agent" => "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36",
                "prospector" => {
        "type" => "log"
    },
              "http_referer" => "-",
                   "real_ip" => "",
                   "fileset" => {
        "module" => "nginx",
          "name" => "access"
    },
           "upstream_status" => "-",
           "body_bytes_sent" => "0",
                "@timestamp" => 2019-09-14T07:03:36.087Z,
      "http_x_forwarded_for" => "-",
                    "status" => 304,
                    "source" => "/www/log/access.log",
                     "input" => {
        "type" => "log"
    },
                "time_local" => "2019-09-14T15:03:28+08:00",
              "request_time" => "0.000",
             "upstream_addr" => "-",
                      "tags" => [
        [0] "beats_input_codec_plain_applied"
    ],
                    "offset" => 11066,
                     "event" => {
        "dataset" => "nginx.access"
    },
                   "request" => "GET / HTTP/1.1"
}

logstash 输出内容

将这两次获取的数据进行一个对比，下面这个数据 message 被删除了，可是 message 中的每一个字段都独立出来了。这样的好处：

　　（1）日志信息更加清晰，可以准确的定位到某一个字段；

　　（2）为后面存储到 elasticsearch 中，进行查询或者筛选作好了准备。

上面这个操做就等因而将原来的 message 分列存放了。

上面这个json 发现有两个时间：

　　@timestamp - 格林尼治时间 - logstash 获取日志时间

　　Time_local - 东八区时间 - nginx日志记录时间

这两个时间的分钟和秒钟并不一致，然后面过滤日志采用的是 @timestamp 时间，也就是 logstash 时间，这就会形成 nginx 日志时间不许确的现象，所以须要将两个时间修改成一致。

{
                  "@version" => "1",
                      "host" => {
                 "name" => "web-node1",
                   "os" => {
                "name" => "CentOS Linux",
             "version" => "7 (Core)",
              "family" => "redhat",
            "platform" => "centos",
            "codename" => "Core"
        },
                   "id" => "4b3b32a1db0343458c4942a10c79acef",
         "architecture" => "x86_64",
        "containerized" => false
    },
    "upstream_response_time" => "-",
                      "beat" => {
            "name" => "web-node1",
         "version" => "6.8.2",
        "hostname" => "web-node1"
    },
                    "domain" => "localhost",
              "request_body" => "-",
                       "log" => {
        "file" => {
            "path" => "/www/log/access.log"
        }
    },
           "http_user_agent" => "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36",
                "prospector" => {
        "type" => "log"
    },
              "http_referer" => "-",
                   "real_ip" => "",
                   "fileset" => {
        "module" => "nginx",
          "name" => "access"
    },
           "upstream_status" => "-",
           "body_bytes_sent" => "0",
                    "status" => 304,
      "http_x_forwarded_for" => "-",
                "@timestamp" => 2019-09-14T07:14:46.000Z,
                    "source" => "/www/log/access.log",
                     "input" => {
        "type" => "log"
    },
                "time_local" => "2019-09-14T15:14:46+08:00",
              "request_time" => "0.000",
             "upstream_addr" => "-",
                      "tags" => [
        [0] "beats_input_codec_plain_applied"
    ],
                    "offset" => 11495,
                     "event" => {
        "dataset" => "nginx.access"
    },
                   "request" => "GET / HTTP/1.1"
}

logstash 输出内容

如今，对比两个时间的分钟和秒钟，彻底一致了。接下来，删除一些没必要要的字段，并重命名一些字段名，修改配置文件以下：

{
           "@version" => "1",
              "agent" => "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36",
             "domain" => "localhost",
       "request_body" => "-",
                "log" => {
        "file" => {
            "path" => "/www/log/access.log"
        }
    },
       "http_referer" => "-",
      "response_time" => [
        [0] "-"
    ],
            "real_ip" => "",
            "fileset" => {
        "module" => "nginx",
          "name" => "access"
    },
    "upstream_status" => "-",
    "body_bytes_sent" => "0",
             "status" => 304,
         "@timestamp" => 2019-09-14T07:22:14.000Z,
         "time_local" => "2019-09-14T15:22:14+08:00",
       "request_time" => "0.000",
      "upstream_addr" => "-",
    "x_forwarded_for" => [
        [0] "-"
    ],
            "request" => "GET / HTTP/1.1"
}

logstash 输出内容

通过重命名和删除没有的字段，json 也变的精简了不少，这样存储 elasticsearch 消耗的存储空间也响应的变小了。

接下来就能够将数据写入到 elasticsearch 中了。在这以前，作的都是 access.log，压根就没考虑到 error.log 的格式，由于 nginx 中 error.log 日志格式没法自定义。

尝试访问一个错误uri 来查看下获取到的数据：

[WARN ] 2019-09-14 15:25:34.300 [[main]>worker3] json - Error parsing json {:source=>"message", :raw=>"2019/09/14 15:25:29 [error] 2122#0: *33 open() \"/www/9527/123.html\" failed (2: No such file or directory), client: 192.168.118.41, server: localhost, request: \"GET /123.html HTTP/1.1\", host: \"192.168.118.16:9527\"", :exception=>#<LogStash::Json::ParserError: Unexpected character ('/' (code 47)): Expected space separating root-level values
 at [Source: (byte[])"2019/09/14 15:25:29 [error] 2122#0: *33 open() "/www/9527/123.html" failed (2: No such file or directory), client: 192.168.118.41, server: localhost, request: "GET /123.html HTTP/1.1", host: "192.168.118.16:9527""; line: 1, column: 6]>}

{
    "@timestamp" => 2019-09-14T07:25:33.173Z,
      "@version" => "1",
           "log" => {
        "file" => {
            "path" => "/www/log/error.log"
        }
    },
       "fileset" => {
        "module" => "nginx",
          "name" => "error"
    },
       "message" => "2019/09/14 15:25:29 [error] 2122#0: *33 open() \"/www/9527/123.html\" failed (2: No such file or directory), client: 192.168.118.41, server: localhost, request: \"GET /123.html HTTP/1.1\", host: \"192.168.118.16:9527\""
}

logstash 输出内容

error.log 过来的数据就变成上面这个样子了。这又是个问题，作 ELK 一是为了分析数据，二是为了尽快排错，若是 ELK 连这个都作不到，那就有点鸡肋了。

上面的这个格式看起来又是很乱了，nginx 错误日志都在 message 中，虽然nginx 错误日志没法定义格式，可是 logstash 能够经过正则表达式来将它转换为 json 格式。但在这以前，应该考虑，access.log 和 error.log 是两种不一样的格式，不能用同一种方式去匹配。那怎么判断数据是来自 access.log 仍是 error.log 呢？

这里语法确定是想到了：

If … {
Access.log
} elseif … {
Error.log
}

对，语法没错，可是用什么条件呢？查看上面的日志，不难发现每次都有这样的字段：

Access.log 日志数据：
            "fileset" => {
        "module" => "nginx",
          "name" => "access"

error.log 日志数据：
       "fileset" => {
        "module" => "nginx",
          "name" => "error"

这样，就有判断的依据了，根据logstash配置语法开始写：

到目前为止，logstash 的 nginx 日志收集过滤配置文件以下：

配置文件名：nginx.conf

input {
    beats {
        port => "5044"    
    }    
}

filter {
    if [fileset][name] == "access" {
        json {
            source => "message"
            remove_field => "message"
            remove_field => "@timestamp"
        }
        date {
            match => ["time_local", "ISO8601"]
            target => "@timestamp"
        }
        grok {
            match => { "request" => "%{WORD:method} (?<url>.* )" }
        }
        mutate {
            remove_field => ["host","event","input","request","offset","prospector","source","type","tags","beat"]
            rename => {"http_user_agent" => "agent"}
            rename => {"upstream_response_time" => "response_time"}
            rename => {"http_x_forwarded_for" => "x_forwarded_for"}
            split => {"x_forwarded_for" => ", "}
            split => {"response_time" => ", "}
        }
        geoip {
            source => "real_ip"
        }
    }
    if [fileset][name] == "error" {
        mutate {
            remove_field => ["@timestamp"]
        }
        grok {
            match => {"message" => "(?<datetime>%{YEAR}[./-]%{MONTHNUM}[./-]%{MONTHDAY}[- ]%{TIME}) \[%{LOGLEVEL:severity}\] %{POSINT:pid}#%{NUMBER}: %{GREEDYDATA:errormessage}(?:, client: (?<real_ip>%{IP}|%{HOSTNAME}))(?:, server: %{IPORHOST:domain}?)(?:, request: %{QS:request})?(?:, upstream: (?<upstream>\"%{URI}\"|%{QS}))?(?:, host: %{QS:request_host})?(?:, referrer: \"%{URI:referrer}\")?"}
        }
        date {
            match => ["datetime", "yyyy/MM/dd HH:mm:ss"]
            target => "@timestamp"
        }
        mutate {
            remove_field => ["message","request","http_referer","host","event","input","offset","prospector","source","type","tags","beat"]
        }
    }
}

output {
    stdout {
        codec => "rubydebug"        
    }
}

nginx.conf

测试 access.log 日志格式数据：

{
           "@version" => "1",
              "agent" => "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36",
             "domain" => "localhost",
       "request_body" => "-",
                "log" => {
        "file" => {
            "path" => "/www/log/access.log"
        }
    },
       "http_referer" => "-",
      "response_time" => [
        [0] "-"
    ],
            "real_ip" => "",
            "fileset" => {
        "module" => "nginx",
          "name" => "access"
    },
    "upstream_status" => "-",
    "body_bytes_sent" => "0",
             "status" => 304,
         "@timestamp" => 2019-09-14T07:39:50.000Z,
         "time_local" => "2019-09-14T15:39:50+08:00",
       "request_time" => "0.000",
      "upstream_addr" => "-",
    "x_forwarded_for" => [
        [0] "-"
    ],
            "request" => "GET / HTTP/1.1"
}

logstash 输出内容

测试 error.log 日志格式数据：

{
           "@version" => "1",
              "agent" => "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/76.0.3809.132 Safari/537.36",
             "domain" => "localhost",
       "request_body" => "-",
                "log" => {
        "file" => {
            "path" => "/www/log/access.log"
        }
    },
       "http_referer" => "-",
      "response_time" => [
        [0] "-"
    ],
            "real_ip" => "",
            "fileset" => {
        "module" => "nginx",
          "name" => "access"
    },
    "upstream_status" => "-",
    "body_bytes_sent" => "571",
             "status" => 404,
         "@timestamp" => 2019-09-14T07:41:48.000Z,
         "time_local" => "2019-09-14T15:41:48+08:00",
       "request_time" => "0.000",
      "upstream_addr" => "-",
    "x_forwarded_for" => [
        [0] "-"
    ],
            "request" => "GET /123.html HTTP/1.1"
}

logstash 输出内容

这下没问题了，两种格式的数据都获取到了。接下来就将数据写入到 elasticsearch中。

到目前为止，logstash 配置文件 nginx.conf 以下：

input {
    beats {
        port => "5044"    
    }    
}

filter {
    if [fileset][name] == "access" {
        json {
            source => "message"
            remove_field => "message"
            remove_field => "@timestamp"
        }
        date {
            match => ["time_local", "ISO8601"]
            target => "@timestamp"
        }
        grok {
            match => { "request" => "%{WORD:method} (?<url>.* )" }
        }
        mutate {
            remove_field => ["host","event","input","request","offset","prospector","source","type","tags","beat"]
            rename => {"http_user_agent" => "agent"}
            rename => {"upstream_response_time" => "response_time"}
            rename => {"http_x_forwarded_for" => "x_forwarded_for"}
            split => {"x_forwarded_for" => ", "}
            split => {"response_time" => ", "}
        }
        geoip {
            source => "real_ip"
        }
    }
    if [fileset][name] == "error" {
        mutate {
            remove_field => ["@timestamp"]
        }
        grok {
            match => {"message" => "(?<datetime>%{YEAR}[./-]%{MONTHNUM}[./-]%{MONTHDAY}[- ]%{TIME}) \[%{LOGLEVEL:severity}\] %{POSINT:pid}#%{NUMBER}: %{GREEDYDATA:errormessage}(?:, client: (?<real_ip>%{IP}|%{HOSTNAME}))(?:, server: %{IPORHOST:domain}?)(?:, request: %{QS:request})?(?:, upstream: (?<upstream>\"%{URI}\"|%{QS}))?(?:, host: %{QS:request_host})?(?:, referrer: \"%{URI:referrer}\")?"}
        }
        date {
            match => ["datetime", "yyyy/MM/dd HH:mm:ss"]
            target => "@timestamp"
        }
        mutate {
            remove_field => ["message","request","http_referer","host","event","input","offset","prospector","source","type","tags","beat"]
        }
    }
}

#output {
#    stdout {
#        codec => "rubydebug"        
#    }
#}
output {
    elasticsearch {
        hosts => ["192.168.118.14"]
        index => "logstash-nginx-%{+YYYY.MM.dd}"
    }
}

nginx.conf

这个配置也算是本次 nginx 最终版配置了。

使用浏览器屡次访问nginx 9527 端口，而后切换到 elasticsearch-head 查看索引是否建立成功。

ok，已经看到今天的索引建立成功，查看数据。

数据也是没有问题的，切换到 kibana 添加索引。

ok，目前已经将数据存储到 elasticsearch 并经过 kibana 展现出来了，可是想要更清晰的分析查看数据还须要在 kibana 上下一番功夫。

2.4 kibana 展现

首先是 Discover 这里，每次进来，都须要一目了然的查看日志，作如下配置：

上面两个设置之后，每次登陆进来只须要点击打开查看相关模板就能看到清晰的日志数据。

接下来，就是绘制最上面那副图啦。

在绘制以前必需要有数据支撑，由于这个是测试环境没有真是的用户访问。所以须要造一批假数据访问。

方法就是直接去 access.log 里复制一条数据，修改 real_ip 为公网ip

假数据添加成功后，来进行图表的配置，点击可视化

第一个：访问省会城市 TOP 5 （饼图）

选择饼图，而后选择 logstash-nginx-* 索引

完成后点击保存。

第二个：访问分布地图（坐标地图）

完成后点击保存。

第三个：域名TOP5 （数据表）

完成后点击保存。

第四个：后端服务TOP5（数据表）

完成后点击保存。

第五个：uri top 5（数据表）

完成后点击保存。

第六个：realipTOP5 （水平条形图）

完成后点击保存。

第七个：http状态TOP5 （饼图）

完成后点击保存。

好了，在可视化一栏中，建立了 7 个数据表图，点开仪表板，将这些图表展现出来就好了。

而后将图表摆放好，大功告成。