原文链接 http://codepub.cn/2017/09/29/logstash-offline-install-plugin/
注：以下为加速网络访问所做的原文缓存，经过重新格式化，可能存在格式方面的问题，或偶有遗漏信息，请以原文为准。
如果线上服务器可以连外网的话，当然是用官方提供的命令来安装插件最简单了，但是可惜的是，好多公司线上服务器是没有外网访问权限的，这就需要在使用某些插件的时候，进行离线安装。而离线安装有两种方式，一种是在可以联网的机器上安装插件，之后使用prepare-offline-pack命令打包，然后将打包文件上传到不能联网的服务器，再使用prepare-offline-pack解包，安装。但是这种方式太麻烦，要求你必须要有一个可以联网的机器，最好还是和不能联网的服务器相同的配置环境，这里推荐一种更好的方案，来解决离线安装插件的问题。
先演示一下，正常的联网环境是如何操作的，如下所示
[elastic@escluster logstash-5.5.0]$ pwd
/home/elastic/elasticsearch/logstash-5.5.0
[elastic@escluster logstash-5.5.0]$ ./bin/logstash-plugin install logstash-filter-fingerprint
Validating logstash-filter-fingerprint
Installing logstash-filter-fingerprint
Installation successful
那么无法联网，首先需要在可以联网的机器上下载对应插件的压缩包，打开Logstash Plugins地址，直接搜索需要安装的插件名称，然后下载对应的zip或者tar.gz压缩包即可。也许你会说，我用的Logstash是5.5.0的，但是并没有对应版本的插件啊？不用担心，试一下如下命令，显示已经安装的所有插件
[elastic@escluster logstash-5.5.0]$ ls -la vendor/bundle/jruby/1.9/gems
total 652
drwxrwxr-x. 203 elastic elastic 8192 Jun 30 23:56 .
drwxrwxr-x. 9 elastic elastic 104 Jun 30 23:56 ..
drwxrwxr-x. 7 elastic elastic 4096 Jun 30 23:56 addressable-2.3.8
drwxrwxr-x. 3 elastic elastic 4096 Jun 30 23:56 arr-pm-0.0.10
drwxrwxr-x. 6 elastic elastic 4096 Jun 30 23:56 atomic-1.1.99-java
drwxrwxr-x. 5 elastic elastic 55 Jun 30 23:56 avl_tree-1.2.1
drwxrwxr-x. 4 elastic elastic 4096 Jun 30 23:56 awesome_print-1.8.0
drwxrwxr-x. 3 elastic elastic 16 Jun 30 23:56 aws-sdk-2.3.22
drwxrwxr-x. 5 elastic elastic 104 Jun 30 23:56 aws-sdk-core-2.3.22
drwxrwxr-x. 3 elastic elastic 16 Jun 30 23:56 aws-sdk-resources-2.3.22
drwxrwxr-x. 5 elastic elastic 4096 Jun 30 23:56 aws-sdk-v1-1.67.0
drwxrwxr-x. 7 elastic elastic 4096 Jun 30 23:56 backports-3.8.0
......
......
可以看到，各种版本的插件都有，所以说，插件的版本和Logstash的版本并不要求一致，以安装logstash-filter-fingerprint插件为例，目前最新版是v3.1.1，下载上传到无法联网的服务器上，解压
[elastic@escluster ~]$ gunzip logstash-filter-fingerprint-3.1.1.tar.gz
[elastic@escluster ~]$ tar -xvf logstash-filter-fingerprint-3.1.1.tar
进入Logstash的目录，编辑Gemfile文件，在文件开头添加
gem "logstash-filter-fingerprint", :path => "/home/elastic/logstash-filter-fingerprint-3.1.1"
保存退出，执行命令./bin/logstash-plugin install --no-verify安装，提示如下信息
[elastic@escluster logstash-5.5.0]$ ./bin/logstash-plugin install --no-verify
Installing...
LogStash::GemfileError: duplicate gem logstash-filter-fingerprint
add_gem at /home/elastic/elasticsearch/logstash-5.5.0/lib/pluginmanager/gemfile.rb:109
gem at /home/elastic/elasticsearch/logstash-5.5.0/lib/pluginmanager/gemfile.rb:207
(eval) at (eval):52
instance_eval at org/jruby/RubyBasicObject.java:1598
parse at /home/elastic/elasticsearch/logstash-5.5.0/lib/pluginmanager/gemfile.rb:195
load at /home/elastic/elasticsearch/logstash-5.5.0/lib/pluginmanager/gemfile.rb:19
gemfile at /home/elastic/elasticsearch/logstash-5.5.0/lib/pluginmanager/command.rb:4
install_gems_list! at /home/elastic/elasticsearch/logstash-5.5.0/lib/pluginmanager/install.rb:146
execute at /home/elastic/elasticsearch/logstash-5.5.0/lib/pluginmanager/install.rb:61
run at /home/elastic/elasticsearch/logstash-5.5.0/vendor/bundle/jruby/1.9/gems/clamp-0.6.5/lib/clamp/command.rb:67
execute at /home/elastic/elasticsearch/logstash-5.5.0/vendor/bundle/jruby/1.9/gems/clamp-0.6.5/lib/clamp/subcommand/execution.rb:11
run at /home/elastic/elasticsearch/logstash-5.5.0/vendor/bundle/jruby/1.9/gems/clamp-0.6.5/lib/clamp/command.rb:67
run at /home/elastic/elasticsearch/logstash-5.5.0/vendor/bundle/jruby/1.9/gems/clamp-0.6.5/lib/clamp/command.rb:132
(root) at /home/elastic/elasticsearch/logstash-5.5.0/lib/pluginmanager/main.rb:48
很清晰，这是说在Gemfile中存在重复的logstash-filter-fingerprint，因为在原始的Gemfile中，存在通过联网进行安装的logstash-filter-fingerprint，打开Gemfile，找到并注释掉即可
# gem "logstash-filter-fingerprint"
再次执行安装命令，即可安装成功
[elastic@escluster logstash-5.5.0]$ ./bin/logstash-plugin install --no-verify
Installing...
Installation successful