Integrating Watcher with Shield

Watcher can work alongside Shield and integrates with it. This integation is expected to be extended in future releases.

When the Watcher plugin is installed along side Shield, it will automatically register an internal user - __watcher_user. All actions taken as part of a watch execution will be executed on behalf of this user.

Note

The __watcher_user is internal to watcher. Sending executing API on behalf of that users outside of watcher will fail (unless you specifically add such a user to any of the supported realms).

In addition to that, Watcher also registers with Shield two additional cluster level privileges:

  • monitor_watcher - grants access to watcher stats and get APIs
  • manage_watcher - grants access to all watcher APIs

You can use the privileges above in Shield’s roles.yml file to grant roles access to the watcher APIs. The following snippet shows an example of such role definition:

watcher_admin:
    cluster: manage_watcher

Once the relevant role was defined, adding the watcher administrator user requires the exact same process as adding any other user to to Shield. For example, if you are using the esusers realm, use the esusers command-line tool to add the user:

bin/shield/esusers useradd john -r watcher_admin

Once added, this user will be able to call all the watcher APIs and by that manage all watches.

Privileges On Watcher Internal Indices

Watcher stores its data (watches and watch history records) in its own internal indices:

  • .watches - an index that stores all the added watches
  • .watch_history-<timestamp> - time based indices that store all the watch records

All write operations on these indices are performed internally by Watcher itself and external users should not write directly to them. It should be considered a best practice to not grant any write privileges on these indices to any of the Shield users.

Handling Sensitive Information

Sometimes a watch may hold sensitive information. For example, the user password that is configured as part of the basic authentication in the http input. In addition, some of watcher configuration may also hold sensitive data. When Shield is installed, Watcher can utilize some of the security services it provides to better secure this type of sensitive information.

Watch Data Encryption

By default, Watcher simply stores this sensitive data as part of the watch document in the .watches index. This means that the password can be retrieved in plain text by executing a document GET or any search of the available operations in elasticsearch over that index.

Note

The Get Watch API will automatically filter out this sensitive data from its response.

When Shield is installed, it is possible configure watcher to use shield and encrypt this sensitive data prior to indexing the watch. This can be done by:

  • Ensuring Shield’s System Key is set up and used
  • Add the following settings in the elasticsearch.yml file:

    watcher.shield.encrypt_sensitive_data: true

    By default (when not set), the sensitive data will be index in plain text (same behaviour as when shield is not installed)

Sensitive Data in Configuration Files

The elasticsearch.yml file may also hold sensitive data. For example, the SMTP credentials that are configured as part of the email accounts.

As for now, neither Watcher nor Shield provide a mechanism to encrypt settings in this file. It is a best practice to ensure that access to this file is limited to the user under which the elasticsearch instance is running.

In addition to that, When Shield is installed, these settings will be filtered out from the REST Nodes Info API.