docker容器虽然支持gelf日志驱动，却不支持合并多行日志为1个message，详情见 log driver should support multiline · Issue #22920 · moby/moby · GitHub

，这导致在graylog查看java应用的报错日志时非常不方便。

 

解决思路：用logstash处理后再发给graylog。

1、docker安装logstash

将 /usr/share/logstash/conf.d/ 目录映射出来，方便编辑配置文件

mkdir -p  /opt/logstash/conf.d/

vi /opt/logstash/logstash.yml

logstash.yml内容如下：

path.config: /usr/share/logstash/conf.d/*.conf
path.logs: /var/log/logstash

 

vi /opt/logstash/conf.d/test.conf

input {
    file{
        path => "/usr/share/logstash/conf.d/test.log"
        start_position => "beginning"
        type=>"runtimelog"
                codec=> multiline {
                        pattern => "^%{TIMESTAMP_ISO8601} "
                        negate => true
                        what => "previous"
                }
	}
}

filter {}

output {
	stdout {
        	codec => rubydebug      
	}
}

 

docker run -d -p 5044:5044 -p 5045:5045 -p 12200:12200/udp --name logstash -v /opt/logstash/logstash.yml:/usr/share/logstash/config/logstash.yml -v /opt/logstash/conf.d/:/usr/share/logstash/conf.d/ logstash:7.16.1

 

2、进入容器内安装插件

logstash-plugin install logstash-output-gelf
logstash-plugin install logstash-input-gelf

 安装完插件再添加相关conf

vi /opt/logstash/conf.d/app.conf

input {
    gelf {
	port =>12200
	host => "0.0.0.0"
        codec => multiline {
            pattern => "^%{TIMESTAMP_ISO8601} "
            negate => true
            what => "previous"
        }
    }
}

filter {}

output {
    gelf {
	host => "172.17.0.1"
        port => 12201
        protocol => "UDP"
    }
}

测试结果：input类型为file时，multiline编码正常，input类型为gelf时，无效...

参考链接：docker - logstash-5.x gelf input multiline codec doesn't work - Stack Overflow

 

既然logstash行不通，换成fluent-bit试试：

mkdir -p /opt/fluent-bit/

vi /opt/fluent-bit/fluent-bit.conf

[INPUT]
    name              forward
    Listen            0.0.0.0
    Port              24224
    Buffer_Chunk_Size 1M
    Buffer_Max_Size   6M
    #Multiline	      On
    #Parser_Firstline  multiline_pattern

[OUTPUT]
    Name                    gelf
    Match                   *
    Host                    172.17.0.1
    Port                    12201
    Mode                    udp
    Gelf_Short_Message_Key  log

docker run -d --name fluent -p 24224:24224 -p 24224:24224/udp -v /opt/fluent-bit/fluent-bit.conf:/fluent-bit/etc/fluent-bit.conf fluent/fluent-bit:1.8

很遗憾，fluent-bit的input类型为forward时，也不支持Multiline处理... unknown configuration property 'Multiline'. The following properties are allowed: unix_path, buffer_chunk_size, and buffer_max_size.

参考链接：logging - Does Fluent Bit Input plugin "forward" support multi-line logs processing? - Stack Overflow