我用来安装elasticsearch-transport-couchbase插件非常容易，但是这次它并不顺利。为elasticsearch安装elasticsearch-transport-couchbase 2.1 failes
首先，我试图安装使用自述为波纹管插件：
bin/plugin -install transport-couchbase -url http://packages.couchbase.com.s3.amazonaws.com/releases/elastic-search-adapter/2.1.1/elasticsearch-transport-couchbase-2.1.1.zip
返回以下错误：
ERROR: unknown command [-install]. Use [-h] option to list available commands
A plugin can also be downloaded directly from a custom location by specifying the URL:
sudo bin/plugin install [url]
我尝试这样做：
bin/plugin install http://packages.couchbase.com.s3.amazonaws.com/releases/elastic-search-adapter/2.1.1/elasticsearch-transport-couchbase-2.1.1.zip
而结果是：
Downloading .........................................................................................................................DONE Verifying http://packages.couchbase.com.s3.amazonaws.com/releases/elastic-search-adapter/2.1.1/elasticsearch-transport-couchbase-2.1.1.zip checksums if available ... Failed: IOException[Server returned HTTP response code: 403 for URL: http://packages.couchbase.com.s3.amazonaws.com/releases/elastic-search-adapter/2.1.1/elasticsearch-transport-couchbase-2.1.1.zip.sha1] ; nested: IOException[Server returned HTTP response code: 403 for URL: http://packages.couchbase.com.s3.amazonaws.com/releases/elastic-search-adapter/2.1.1/elasticsearch-transport-couchbase-2.1.1.zip.sha1] ; NOTE: Unable to verify checksum for downloaded plugin (unable to find .sha1 or .md5 file to verify) ERROR: Could not find plugin descriptor 'plugin-descriptor.properties' in plugin zip
如何安装插件？