发生 Ruby 异常：logstash 中未定义的方法"to_json"

Question

只是好奇如何修复Ruby异常发生：未定义的方法'to_json'？

日志版本是 6.3.2。

"journalctl -u logstash" 返回：

May 15 13:33:13 server-4-eu-central-1.sample.com logstash[2382]: [2020-05-15T13:33:13,818][ERROR][logstash.filters.ruby    ] Ruby exception occurred: undefined method `to_json' for #<Hash:0x7a9ee4b7>
May 15 13:33:13 server-4-eu-central-1.sample.com logstash[2382]: [2020-05-15T13:33:13,819][ERROR][logstash.filters.ruby    ] Ruby exception occurred: undefined method `to_json' for #<Hash:0x1a6464f3>
May 15 13:33:13 server-4-eu-central-1.sample.com logstash[2382]: [2020-05-15T13:33:13,820][ERROR][logstash.filters.ruby    ] Ruby exception occurred: undefined method `to_json' for #<Hash:0x34a23ab2>
...

我的 000_sample.conf 配置文件：

input { ...  }
filter {
if [type] == "sample-client-logs" {
json {
source => "message"
}
...
if [principal] =~ /(?i)sfe|android|ios|kraken-analytics/ {
json {
source => "message"
target => "[jsonPayload][message]"
add_field => {
"[jsonPayload][customer]" => "server-4-eu-central-1"
"[jsonPayload][source]" => "sample-client-logs.log"
"[jsonPayload][serviceContext][service]" => "cloud-log-harvester"
"[jsonPayload][serviceContext][version]" => "null"
"[jsonPayload][principal]" => "%{[jsonPayload][message][principal]}"
"[resource][labels][instance_id]" => "%{host}"
"[resource][labels][region]" => "aws:"
"[resource][type]" => "aws_instance"
}
remove_field => ["message", "[jsonPayload][message][message]", "env", "logicalRegion", "@timestamp", "@version", "path", "host"]
}
ruby {
code => 'event.set("[jsonPayload][message]", event.get("[jsonPayload][message]").to_json)'
}
}
...
}
...
}
output {...}

Answer 1

我找到了答案：

ruby {
code => "
require 'json'
event.set('[jsonPayload][message]', event.get('[jsonPayload][message]').to_json)
"
}

注意不要将"=>"替换为"="，并注意将双引号更改为单引号。