Elasticsearch 提供免費版本的安全功能

Elasticsearch 決定將基本的安全功能從付費功能轉為免費釋出,很明顯的是受到 Open Distro for Elasticsearch 的壓力而做出的改變:「Security for Elasticsearch is now free」。

要注意的是這不是 open source 版本,只是將這些功能放到 basic tier 裡讓使用者免費使用:

Previously, these core security features required a paid Gold subscription. Now they are free as a part of the Basic tier. Note that our advanced security features — from single sign-on and Active Directory/LDAP authentication to field- and document-level security — remain paid features.

這代表 Open Distro for Elasticsearch 提供的還是比較多:

With Open Distro for Elasticsearch, you can leverage your existing authentication infrastructure such as LDAP/Active Directory, SAML, Kerberos, JSON web tokens, TLS certificates, and Proxy authentication/SSO for user authentication. An internal user repository with support for basic HTTP authentication is also avaliable for easy setup and evaluation.

Granular, role-based access control enables you to control the actions a user can perform on your Elasticsearch cluster. Roles control cluster operations, access to indices, and even the fields and documents users can access. Open Distro for Elasticsearch also supports multi-tenant environments, allowing multiple teams to share the same cluster while only being able to access their team's data and dashboards.

目前看起來還是可以朝 Open Distro for Elasticsearch 靠過去...

改 Open Distro for Elasticsearch 預設密碼的方式

AWS 弄出來的 Open Distro for Elasticsearch 因為內建了安全性的功能 (參考「AWS 對 Elastic Stack 實作免費的開源版本 Open Distro for Elasticsearch」),應該是目前新架設 Elasticsearch 的首選。

不過裝好後預設有五個帳號,但從 Open Distro 的 Kibana 介面無法修改改其中兩個使用者的密碼 (adminkibanaserver),要修改密碼發現得花不少功夫,不知道為什麼要這樣設計 :/

這邊講的是透過 RPM (以及 deb) 的方式的修改方式,如果是 Docker 的方式請參考後面提到在 AWS blog 上的文章:「Change your Admin Passwords in Open Distro for Elasticsearch」。

首先先透過 hash.sh 產生 bcrypt 的 hash,像是這樣 (輸入 password 當密碼):

bash /usr/share/elasticsearch/plugins/opendistro_security/tools/hash.sh
WARNING: JAVA_HOME not set, will use /usr/bin/java

然後修改 /usr/share/elasticsearch/plugins/opendistro_security/securityconfig/internal_users.yml 檔案裡面的值,順便改掉 readonly 的部分。

接下來是把這個 internal_users.yml 檔案的設定更新到 Elasticsearch 裡。由於這邊需要讀 /etc/elasticsearch/ 的東西,所以偷懶用 root 跑:

sudo bash /usr/share/elasticsearch/plugins/opendistro_security/tools/securityadmin.sh -cd ../securityconfig/ -icl -nhnv -cacert /etc/elasticsearch/root-ca.pem -cert /etc/elasticsearch/kirk.pem -key /etc/elasticsearch/kirk-key.pem

做完後可能要重跑 Elasticsearch 與 Kibana:

sudo service elasticsearch restart
sudo service kibana restart

或是重開機... 順便測試看看重開後有沒有生效。理論上修改完成後,就是用新的帳號密碼連到 Kibana。

上面的方法是參考了「Default Password Reset」(先找到這篇) 與「change admin password」(後來在 AWS blog 的文章上發現的 GitHub issue 連結) 這邊的資訊。

官方的說明文件則是在寫這篇文章時才找到的,平常搜尋時不太會出現:「Apply configuration changes」。

Open Distro for Elasticsearch 的比較

先前提到的「AWS 對 Elastic Stack 實作免費的開源版本 Open Distro for Elasticsearch」,在「Open Distro for Elasticsearch Review」這邊有整理了一份重點:


AWS 對 Elastic Stack 實作免費的開源版本 Open Distro for Elasticsearch

Elasticsearch 的主體是 Apache License 2.0,但 Elastic Stack (以前叫做 X-Pack) 則是需要付費使用的功能,其中包括了不少跟安全有關的項目在裡面,所以其實有不少人抱怨過產品凌駕安全性的問題,像是「ES 6.3: X-Pack Licence is "Expired" on New Install」這篇官方回應的:

A basic license is not entitled to security features. To try out security you need to use a trial license or obtain a subscription.

AWS 這次則是出手實作了他們自己的版本,叫做 Open Distro for Elasticsearch:「New – Open Distro for Elasticsearch」。

如果你看文章說明,他列出來的 feature 全部都是在 Elastic Stack 這頁上列出來的項目,針對性的意思其實很清楚了:

In addition to Elasticsearch and Kibana, the first release includes a set of advanced security, event monitoring & alerting, performance analysis, and SQL query features (more on those in a bit).


Security – This plugin that supports node-to-node encryption, five types of authentication (basic, Active Directory, LDAP, Kerberos, and SAML), role-based access controls at multiple levels (clusters, indices, documents, and fields), audit logging, and cross-cluster search so that any node in a cluster can run search requests across other nodes in the cluster.

目前支援 Docker Image 與 RPM,之後看看有沒有機會出 deb 版本:

In addition to the source code repo, Open Distro for Elasticsearch and Kibana are available as RPM and Docker containers, with separate downloads for the SQL JDBC and the PerfTop CLI.

這樣應該會讓 Elasticsearch 的服務模式受到很大的影響,來看 Elastic N.V. Ordinary Shares Real Time Stock Quotes 這邊會掉多少...