Hosts Discovery

Add a discovery job

To launch a discovery, you need to add a discovery job.

The job addition wizard is a six steps wizard that will allow you to choose a provider, define parameters, define mapping rules and update/execution policies.

Go to Configuration > Hosts > Discovery and click on +ADD.

Choose a provider

First, choose a provider by clicking on it:

The search bar allows to search for a specific provider:

The discovery providers are provided from installation of Plugin Packs (Azure, Amazon AWS, VMware, etc.). To know the complete list, please go to the Plugin Packs catalog.

A job name can be defined to identify it. The provider name will be used by default.

Define access and discovery parameters

The second step allows to define access parameters, especially the monitoring server from which the discovery will be made:

Some providers ask for other parameters such as a proxy if the discovery is made on an online service and/or credentials.

Then, some additional parameters might be needed to define the scope of the discovery:

Set mappers

The fourth step defines how the discovery result will be processed to create hosts in the configuration.

In this step, mappers can be added or rearranged to match needs. See the How to use the mappers chapter to know more.

Realtime simulation on a set of example data gives a preview of what the discovery result could look like:

Define analysis and update policies

The fifth step allows to choose between two analysis methods and define configuration update policies.

Manual analysis

Manual analysis will need user to choose what to add to the configuration through the result page after the job successfully finish.

Automatic analysis

Automatic analysis will process the result automatically and will use the choosen policies between the following:

• Add hosts to configuration when they are discovered for the first time
• Disable hosts already added to configuration if the mapping rule excludes them
• Enable hosts already added to configuration if they are discovered but disabled

At least one of these policies must be selected.

Note: not discovered hosts (or no more discovered hosts) will not result to disabled hosts in the Centreon configuration. Only discovered and at the same time excluded hosts can be disabled in the configuration (see exclusion mapper).

Read the example below to better understand the scope of these policies.

Plan execution

The last step allows to choose between two execution methods.

Execute immediately

The immediate execution will launch the discovery right after the job creation.

Schedule execution

The scheduled execution allows to choose between several types of scheduling:

• Every year at defined days of defined months and defined time

• Every month at defined days of the month and defined time

• Every week at defined days of the week and defined time

• Every day at defined time

• Every x hours (at defined minutes)

• Every x minutes

Click on FINISH to add and execute or schedule the discovery job.

Manage discovery jobs

Go to the Configuration > Hosts > Discovery menu to access to the list of discovery jobs.

The status of a job can be:

• Scheduled
• Running
• Saving
• Finished
• Failed

If a job is on a Failed status, hover on to the icon to know the reason.

If a job is on a Finished status, click on it to analyse the result. See Analyse a discovery job result to know more.

Several actions can be done on jobs:

• Jobs can be re-executed using the Force execution action
• They can also be edited
• Or even deleted
• If the job is scheduled, it can be paused
• And resumed

Analyse a discovery job result

From the Configuration > Hosts > Discovery menu, click on a Finished job to visualize the result.

The mappers linked to this job can be edited and applied directly on the result by clicking the edit action

Select the hosts you want to add to the configuration and click on the save action

A task will be launched in background to save the hosts and create the services linked to host templates.

Go to the Configuration > Hosts menu to see the newly created hosts.

If the hosts you selected are not visible in the configuration, go back to the job listing and see if an error occured during the saving task.

Edit a discovery job

From the Configuration > Hosts > Discovery menu, click on the Edit action.

On the panel on the right, every parameters of the job can be edited.

Edition of the mapper will have a direct effect on the job result.

Click on the Save icon

How to use the mappers

A mapper is an object letting you map an attribute's value of a discovered item to a property of a future host.

There is six types of mappers:

• Association: map an attribute's value to a common host property like name, alias or IP,
• Macro: map an attribute's value to a host custom macro,
• Template: add a host template,
• Monitoring: choose from which monitoring server will be monitored the host,
• Exclusion: exclude a subset of hosts based on their attributes (see the example below),
• Inclusion: include a subset of hosts that may be excluded.

For all those mappers, conditions can be applied to choose whether or not the mapping will actually occur.

Conditions are also based on attributes value to which a user defined value is compared using operators. Operators can be : equal, not equal, contain and not contain.

The list of attributes depends on the provider and are listed as Source for both mappers and conditions.

Add a mapper

From the job wizard at step four, or from the edition panel in the Mappers section, click on +ADD MAPPER.

Select the type of mapper from the drop-down list, and fill every required fields.

Click on SAVE to add the mapper.

Edit a mapper

From the job wizard at step four, or from the edition panel in the Mappers section, click on the Edit icon

Change any fields wanted or even the type of mapper.

Click on SAVE to save the mapper.

Delete a mapper

From the job wizard at step four, or from the edition panel in the Mappers section, click on the Delete icon

A popin window will ask you to confirm the action.

Click on DELETE to delete the mapper.

Mappers types

Association

The Association mapper is used to set common properties of a host like its name, alias or IP address. Those three properties are mandatory.

The Source listing allows to choose between credentials, parameters or discovery result attributes.

The Destination listing allows to define to which property the value will be mapped.

Macro

The Macro mapper is used to create custom macros to be defined on the host.

The Source listing allows to choose between credentials, parameters or discovery result attributes.

The Destination is a user defined text field.

The Password checkbox defines if the macro will be created as a password macro or not.

Template

The Template mapper is used to add a template to the host. It is not a replace method.

The Host template listing allows to choose among all host templates defined in the configuration.

Monitoring

The Monitoring mapper is used to choose from which monitoring server will be monitored the host.

The Monitoring instance selector radio buttons allow to choose between the monitoring server defined in the job or from the ones available on the Centreon platform.

This mapper is mandatory.

Exclusion

The Exclusion mapper is used to exclude a subset of hosts from the result listing.

The mapper uses hosts attributes as conditions to exclude them.

Inclusion

The Inclusion mapper is used to include a subset of hosts to the result listing.

The mapper uses hosts attributes as conditions to include them.

Examples

Dynamically update your configuration

Situation

Having a VMware vCenter with virtual machines dynamically added, started and stopped.

Objective

Update the Centreon configuration accordingly to the states of the virtual machines.

Create the right job

From the Host Discovery main page, add a job starting by selecting the VMware VM provider.

Define the monitoring instance from which you want to do the discovery. For this particular provider, it has to work with the discovery parameters on which you define the information related to the Centreon VMware Connector access (hostname/ip and port).

In most cases, you will install the Connector on the monitoring instance, so the access will be localhost and default port 5700.

Let's now define the mappers and the update policies to match our needs:

• First needs:

  • Add new (or not yet added) virtual machines, (1)
  • Exclude virtual machines that are not started. (2)

• Second needs:

  • Disable the virtual machines that are stopped, (3)
  • Re-enable the virtual machines that are started (after being stopped). (4)

This will first result as an Exclusion mapper with the following configuration:

This way, all powered off virtual machines will not be part of the processed result. Those will not be added (2).

In addition to this mapper, choose the automatic analysis with all the update policies as below:

With the first policy, the virtual machines part of the processed result will be added (1).

With the second one, virtual machines that were added at some point (because in a powered on state) will be disabled in the Centreon configuration if they happen to be powered off (3).

The last one will enable the virtual machines that are once again in a powered on state (4).

Of course, the last two policies work well if the job is scheduled to run more than one time.

Note: if a virtual machine happens to be deleted, it will not be deleted (or even disabled) from the Centreon configuration. Only discovered and at the same time excluded hosts can be disabled in the configuration (if the policy is chosen).