Ubuntu 16.10: ElasticSearch 5.2.0 外網訪問問題

1、安裝JDK8

 參考：Ubuntu 安裝 JDK 7 / JDK8 的兩種方式

注：ElasticSearch 5.2.0需要JDK8，可以只裝JDK8。

2、下載elasticsearch-5.2.0.tar.gz

3、解壓到/opt/elasticsearch-5.2.0

4、到/opt/elasticsearch-5.2.0/bin目錄下運行：./elasticsearch -v

5、打開新的terminal，運行curl -X GET 'http://localhost:9200'應該可以成功查到默認信息

6、此時，只可以在本機訪問ES，如果需要外網訪問，按照網上找到的很多解決方法都不能成功，這一步花了我很長時間。

解決方法參考：Bootstrap Error

引用如下：

We've just patched the docs to explain a way to opt out that ought to work fine for you. It might take a while to build so here is a link to the fix: https://github.com/elastic/elasticsearch/pull/21220/files227

Essentially, set http.host to the non-local IP while keeping network.host at its default. You can't form a cluster but you can test against a single node. If you want a cluster you'll need to make the bootstrap checks happy.

也就是說，只把http.host設置爲本機ip，保留network.host爲默認值。