SSH Monitoring in ZenPacks

Wed, 14 Dec 2016 00:00:00 +0000

Zenoss usually monitors and collects information using SNMP and SSH methods. A good example of is the linux monitor ZenPack which can collect information such as hard disks, interfaces, and file systems using both methods.

SNMP works by installing and configuring an SNMP agent on the machine we want to monitor. This agent will poll the machine for data, and this data can be retrieved by Zenoss using net-snmp.

On the other hand, SSH works by configuring a username and password or a path to an SSH key zProperties. This will allow Zenoss to remotely access the host using SSH and execute the corresponding commands and return the corresponding information.

When developing ZenPacks, data collection using SNMP is a relatively common practice. There is even a very good tutorial on SNMP monitoring using zenpacklib. When using SNMP, the modeler plugins are SnmpPlugin plugins that typically work using a set of OIDs to determine exactly which data is to be modeled.

SSH in Modeler Plugins

In order to make a modeler plugin utilize SSH as it's polling method we need to use a different type of plugin, the CommandPlugin plugin. The structure of this type of plugin is very similar to the SnmpPlugin, however there is one critical variable that must be implemented.

Keystone Interface in Juju Charms

Fri, 28 Oct 2016 00:00:00 +0000

Juju Charms interfaces make possible the interaction and exchange of data between services deployed by Juju. In this post I will explain how we can use the Keystone interface to make our custom charm service comunicate with the Keystone service within a Juju environment.

In the end, what we really want to achieve, is to link both services so that they can exchange data, using a Juju command:

juju add-relation keystone myservice

Juju Relations

Juju relations operate behind the concept that one service provides something, while another service requires it, and the interaction between the services is done through an interface. Since we want to interact with Keystone, this means that we need to use a suitable keystone interface that allows us to get what we need, the keystone Identity data. For this, we use the keystone-admin interface.

With this in mind, we configure our charm to require this relation and interface in metadata.yaml:

# ...
requires:
  identity-admin:
    interface: keystone-admin

bash on Andrés Álvarez

SSH Monitoring in ZenPacks

SSH in Modeler Plugins

Keystone Interface in Juju Charms

Juju Relations