Enabling SSH on the Switch

Let’s enable SSH on the switch or router, and configure a Puppet user with enough rights to configure the switch. This will be a short review, as all of these commands should be self-evident to an experienced network administrator.

Note that we are doing nothing more than configuring the exact minimum necessary to enable SSH and provide enough configuration (Base IP setup, DNS, and NTP) for Puppet to do all remaining configuration. Be certain to assign a unique hostname and the correct domain name to the unit. The hostname and domain name will be concatenated together by Puppet to create a certname for the unit:

Switch#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
Switch(config)#hostname switch01
switch01(config)#ip domain-name example.com
switch01(config)#ip name-server 192.168.1.10
switch01(config)#ip name-server 192.168.1.11
switch01(config)#ntp server 192.168.1.10
switch01(config)#ntp server 192.168.1.11
switch01(config)#crypto key generate rsa general-keys modulus 2048
The name for the keys will be: switch01.example.com

% The key modulus size is 2048 bits
% Generating 2048 bit RSA keys ...[OK]

switch01(config)#
03:25:35: %SSH-5-ENABLED: SSH 1.99 has been enabled
switch01(config)#ip ssh version 2
switch01(config)#line vty 0 4
switch01(config-line)#transport input ssh
switch01(config-line)#line vty 5 15
switch01(config-line)#transport input ssh
switch01(config-line)#int vlan1
switch01(config-if)#ip address 192.168.1.253 255.255.255.0
switch01(config-if)#exit

Now you should create a privileged user account for the Puppet user. I recommend using an intuitive username like puppet, which would clearly identify the automated process in access logs. Do not share or reuse the login identity of a human.

If you have already customized authentication in your environment, use an authentication setup appropriate for your environment. If you do not have centralized authentication for your network devices, the following can provide a reasonable starting point. Choose appropriate passwords for the following secrets:

switch01(config)#enable secret enable-password
switch01(config)#aaa new-model
switch01(config)#aaa authentication login default local
switch01(config)#aaa authorization exec default local
switch01(config)#username admin priv 15 secret admin-password
switch01(config)#username puppet priv 15 secret puppet-password
switch01(config)#end
switch01#copy run start
Building configuration...
[OK]

The previous example was written using a Cisco 3560 switch. A few of these commands may require different options on newer or older OS versions, but this should provide you with enough information to work out the right commands for your specific unit.

Configuring the Puppet Proxy Agent

Select a node that can complete both of the following network connections:

• SSH to the Cisco switch or router (destination TCP port 22)
• Connect to the Puppet server (destination TCP port 8140)

On this node, create a non-privileged user account to use for device management. There is no reason to use the root account. You can use a single shared account for all devices, or a different user account for each device if you prefer. The process shown here will create a non-privileged user and an appropriate Puppet configuration file:

[vagrant@client ~]$ sudo useradd -U -m -c "Puppet Device Manager" devicemgr
[vagrant@client ~]$ sudo -u devicemgr -i
[devicemgr@client ~]$ mkdir -p .puppetlabs/etc/puppet
[devicemgr@client ~]$ ln -s .puppetlabs/etc/puppet
[devicemgr@client ~]$ $EDITOR .puppetlabs/etc/puppet/puppet.conf

Create ~/.puppetlabs/etc/puppet/puppet.conf with the following settings:

[agent]
  server = puppet.example.com

Create ~/.puppetlabs/etc/puppet/device.conf with a list of devices, their type, and a URL to access them. The URL must contain both the username and password to access the device, and the enable password if required:

[switch01.example.com]
type cisco
url ssh://puppet:password@switch01.example.com/?enable=admin

Secure the file containing passwords, for obvious reasons:

[devicemgr@client ~]$ chmod 0600 .puppetlabs/etc/puppet/device.conf

Now we will connect this network device to the Puppet server, using a process very similar to how new nodes are connected. Initialize the proxy agent for this device with the command puppet device followed by the node name:

$ puppet device switch01.example.com --verbose
applying configuration to switch01.example.com at ssh://switch01.example.com/
Info: Creating a new SSL key for switch01.example.com
Info: Caching certificate for ca
Info: Creating a new SSL certificate request for switch01.example.com
Info: Certificate Request fingerprint (SHA256): 65:FC:AA:E3:F5:E5:5D:05:D0:D9:…
Info: Caching certificate for ca

You may need to run puppet cert sign switch01.example.com on the Puppet server to authorize the network device, and then run the command again.

This process has created a new Puppet agent dedicated to managing this network device. All of the configuration files, TLS certificates, logs, and state files for this device can be found in the ~/.puppetlabs/ directory structure. They never mix or interfere with the Puppet agent running as root on this node.

This network device can now be configured through idempotent declarations in Puppet manifests. Let’s get started making changes.

Installing the Device_Hiera Module

One of the less-than-ideal circumstances around device configuration with Puppet was that each configuration entry on a device required a resource definition in the manifest. This often meant that Puppet device manifests were nearly as long as the device configurations that they generated.

The device_hiera module makes use of Hiera hierarchies and hash merging to utilize default port configurations, and enable DRY network configuration. Instead of specifying each interface specifically, we’ll make use of defaults and then add minimal overrides when necessary.

Let’s install this module on the Puppet server to make switch configuration easier, as shown here:

[vagrant@puppetserver ~]$ puppet module install jorhett/device_hiera
Notice: Preparing to install into 
  /etc/puppetlabs/code/environments/production/modules
Notice: Downloading from https://forgeapi.puppetlabs.com ...
Info: Resolving dependencies ...
Info: Preparing to install ...
Notice: Installing -- do not interrupt ...
/etc/puppetlabs/code/environments/production/modules
└─┬ jorhett-device_hiera (v0.3.0)
  └── puppetlabs-stdlib (v4.9.0)

Defining Resource Defaults in Hiera

In your Hiera data, let’s assign the device_hiera class to this device. Do so by creating a file for this specific device in the Hiera data hierarchy, such as hostname/switch01.yaml:

# node-specific overrides for switch01
classes:
  - device_hiera

Next, list the resource types to be configured on devices. As these types take no action without explicit configuration, we should add this definition to the global common.yaml file for a DRY implementation. In the example shown here, we’ve enabled configuration of VLANs and network interfaces:

# global lookup defaults in common.yaml
device_hiera::resources:
  - vlan
  - interfaces

For each device resource type, define the default parameters to be used. For a DRY implementation, place default values in the global common.yaml file. The following example configures interfaces in dynamic negotiation mode, with an access VLAN ID of 20, if a more specific configuration is not provided:

# global lookup defaults in common.yaml
device_hiera::defaults::vlan:
  ensure: present

device_hiera::defaults::interface:
  description  : 'Default interface configuration'
  mode         : 'dynamic auto'
  encapsulation: 'negotiate'
  access_vlan  : '20'

These definitions don’t do anything by themselves, but instead provide defaults for VLANs or interfaces declared for the device that do not have a custom definition. Keep in mind that these are Puppet resources, so you can use ordering metaparameters to ensure that things happen in a specific order:

# global defaults in common.yaml
device_hiera::defaults::interface:
  access_vlan: '20'
  require    : 'Vlan[20]'

In this case it won’t matter, as the VLAN will be created automatically because it was declared as the access VLAN to use by an automatic dependency. This can be useful in less obvious cases—for example, where a BGP peer resource depends on an access list used by the BGP peer configuration to be added first.

Take a moment to consider the power of this ability to declaratively map infrastructure dependencies using the ordering attributes you learned about in Chapter 7.

Centralizing VLAN Configuration

To configure VLANs on your switches, create a definition like the following example. As VLANs tend to be common across an entire site, you may want to place the VLAN configuration in the global common.yaml file. However, you can also place local VLAN definitions within a more specific file in your Hiera hierarchy, such as hostname/switch01.yaml:

# global lookup defaults in common.yaml
device_hiera::resources:
  - vlan

device_hiera::defaults::vlan:
  ensure: present

device_hiera::vlan:
  '20':
    description: 'Servers'
  '30':
    description: 'Middleware'

This definition would create the common VLANs 20 and 30 on every switch.

Documentation for the vlan resource and parameters can be found at “Type Reference: vlan” on the Puppet docs site.

Applying Default Configs to Interfaces

Interfaces are special because there are so many of them, and you usually have to provide mostly redundant configuration details for each one. To make this easier to handle, the device_hiera module allows you to list slots in the chassis along with a range of ports that should be configured.

Define the device_hiera::interfaces::ports array. Each array value should be a hash with a single key and value pair. The key must be a quoted String value containing the slot name, and the value must also be a quoted String value containing a single range of ports, in the format: MIN-MAX. A slot can be listed multiple times to include multiple port ranges.

This example shows port definitions for a typical Cisco Catalyst 48-port switch with 10G uplinks:

device_hiera::interfaces::ports:
  - 'GigabitEthernet1/0'   : '1-48'
  - 'TenGigabitEthernet1/1': '1-2'

Place the list of slots and ports inside the Hiera data file for each individual device, such as hostname/switch01.yaml. Each of these interfaces will be configured with the default values provided in the device_hiera::defaults::interface configuration, unless the interface is specified in the device_hiera::interfaces::custom hash.

If you have many devices of the same type, take advantage of your Hiera hierarchy and put the slot and port ranges in a Hiera file shared by the same devices. Don’t repeat yourself.

Customizing Interface Configurations

It’s possible to customize the configuration of any interface on the device. Define a device_hiera::interfaces::custom hash inside the Hiera data file for the device, such as hostname/switch01.yaml.

Each entry should be a quoted String hash key of the entire interface name. The value should be a hash with the parameters for the interface resource. Anything not specified will use the default values provided in the device_hiera::defaults::interface hash. The value absent can be used to clear a default value. The interface names can overlap with, or be outside the slots and port ranges supplied in device_hiera::interfaces::ports.

The following example will configure two 10G ports as VLAN-trunking uplink ports:

device_hiera::interfaces::custom:
  'TenGigabitEthernet1/1/3':
     description  : 'Uplink to core 1'
     mode         : 'trunking'
     encapsulation: 'dot1q'

  'TenGigabitEthernet1/1/4':
     description  : 'Uplink to core 2'
     mode         : 'trunking'
     encapsulation: 'dot1q'

One of the advantages of Hiera is that if every switch uses the same ports for uplink to the core, you could place this data in a shared Hiera file, and then override it just once in the definition of the core switch. Take advantage of Hiera’s hash merging to stay DRY.

Testing Out the Switch Configuration

Shown here is the output when I ran puppet device against the 48-port Cisco switch we created the puppet device proxy for, using the preceding example’s Hiera data:

$ puppet device --verbose
Info: starting applying configuration to switch01.example.com
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Caching catalog for switch01.example.com
Info: Applying configuration version '1447670000'
Notice: /Stage[main]/Device_hiera::Vlans/Vlan[20]/ensure: created
Notice: /Stage[main]/Device_hiera::Vlans/Vlan[30]/ensure: created
Notice: /Stage[main]/Device_hiera::Interfaces/Interface[GigabitEthernet1/0/1]/
  access_vlan: access_vlan changed '1' to '20'
Notice: /Stage[main]/Device_hiera::Interfaces/Interface[GigabitEthernet1/0/1]/
  description: defined 'description' as 'Default configuration'
Notice: /Stage[main]/Device_hiera::Interfaces/Interface[GigabitEthernet1/0/2]/
  access_vlan: access_vlan changed '1' to '20'
Notice: /Stage[main]/Device_hiera::Interfaces/Interface[GigabitEthernet1/0/2]/
  description: defined 'description' as 'Default configuration'
 …repeated for ports 3 through 48…
Notice: /Stage[main]/Device_hiera::Interfaces/Interface[TenGigabitEthernet1/1/3]/
    description: defined 'description' as 'uplink to core 1'
Notice: /Stage[main]/Device_hiera::Interfaces/Interface[TenGigabitEthernet1/1/3]/
    mode: mode changed 'dynamic auto' to 'trunk'
Notice: /Stage[main]/Device_hiera::Interfaces/Interface[TenGigabitEthernet1/1/3]/
    encapsulation: encapsulation changed 'negotiate' to 'dot1q'
Notice: /Stage[main]/Device_hiera::Interfaces/Interface[TenGigabitEthernet1/1/4]/
    description: defined 'description' as 'uplink to core 2'
Notice: /Stage[main]/Device_hiera::Interfaces/Interface[TenGigabitEthernet1/1/4]/
    mode: mode changed 'dynamic auto' to 'trunk'
Notice: /Stage[main]/Device_hiera::Interfaces/Interface[TenGigabitEthernet1/1/4]/
    encapsulation: encapsulation changed 'negotiate' to 'dot1q'
Notice: Applied catalog in 63.93 seconds

As you can see, we have configured a VLAN and 50 interfaces on this switch in 63 seconds. That’s a lot faster than doing it by hand, isn’t it?

Adding Resource Types and Providers

Puppet only includes the two resources we’ve just shown for puppet device to use: interface and vlan.

There are modules in the Puppet Forge that provide additional resource types and providers, as well as support for other vendors’ devices. Resources designed for NetDev (described next) only work with an embedded Puppet agent on the device. The following modules from the Puppet Forge are designed to be used with puppet device:

puppetlabs/f5

Manages F5 BIG-IP Application Delivery Controllers

puppetlabs/netapp

Manages resources on NetApp Cluster Data ONTAP devices

puppetlabs/netscalar

Enables Puppet configuration of Citrix NetScaler devices through types and REST-based providers

mburger/networkdevice

Network Device Extensions for Cisco

Note that you will need to install these modules on both the Puppet server and your local Puppet environment, as the manifests are used when the server builds the catalog, but the device providers are used locally by the puppet device agent. So install the module in the device manager account:

[devicemgr@client ~]$ puppet module install mburger/networkdevice

…and also on the Puppet server:

[vagrant@puppetserver ~]$ puppet module install mburger/networkdevice

Merging Defaults with Other Resources

Any other resource type can also be created with parameters supplied in a hash under their title. They can likewise fall back to default values for the type. Values for the resource types and parameters should be taken from the module that provides the resource type in question.

For example, if you have installed the puppetlabs/ciscopuppet module, you could use the following for OSPF configuration:

device_hiera::resources:
  - cisco_interface_ospf

device_hiera::defaults::cisco_interface_ospf:
  ensure: present
  cost  : 200
  ospf  : default

device_hiera::cisco_interface_ospf:
  'Ethernet1/2 default': 
    area: '172.16.0.0'

There’s nothing in the device_hiera module that is specific or tied to puppet device. You can utilize this module just as easily with the embedded Puppet agents we’re going to talk about next.

Finding NetDev Vendor Extensions

There are a growing number of devices with complete NetDev support, including the following:

juniper/netdev_stdlib_junos

Junos Provider code for Networking Device

puppetlabs/ciscopuppet

Cisco Puppet providers and types for NX-OS devices

aristanetworks/netdev_stdlib_eos

NetDev Providers for Arista EOS

mellanox/netdev_stdlib_mlnxos

Provider definition for implementing Networking Device (netdev) Library for Mellanox OS (mlnx-os)

In theory, you can utilize NetDev standard resources across any device. Obviously this works best with things like DNS and less well with custom vendor extensions. Most vendors add their own specific resources in the same or a different Puppet module.

For example, Arista Networks types and providers for configuring EOS devices are available at aristanetworks/eos on the Puppet Forge. Cumulus Linux and Mellanox also have networking components separated into different modules.

Creating a NetDev Device Object

Each device must declare a single netdev_device resource. The NetDev provider creates automatic dependencies between this resource and the other NetDev resources. If this resource fails to be applied, no other NetDev resource will be evaluated.

As this resource takes only a name, the device_hiera module implements the netdev_device type for a simple, one-shot definition. The following two lines of Hiera data will create a unique netdev_device resource for every NetDev vendor:

device_hiera::resources:
  - netdev_device

You can optionally override the name for a given node by defining device_hiera::netdev_device::node_name but this is not necessary. The value of the device’s unique certname is used to avoid duplication.

Reducing Duplication with Device_Hiera

The device_hiera module can also be used with any NetDev extensions module to minimize repetition. The following example creates NetDev resource defaults that can safely be placed in the global common.yaml file:

device_hiera::resources:
  - network_dns
  - network_interface
  - netdev_device

device_hiera::defaults::network_interface:
  duplex: 'full'
  enable: 'true'
  mtu   : '1500'

device_hiera::defaults::network_dns:
  ensure : present
  domain : 'example.com'
  search : ['example.com','example.net']
  servers: ['192.168.51.10','192.168.51.11']

To utilize these defaults, assign the device_hiera class and override parameters as necessary within a specific host’s Hiera configuration data, such as hostname/switch01.yaml:

classes:
  - device_hiera

device_hiera::network_dns:
  settings:
    # this host is outside the firewall, use Google DNS
    servers: ['8.8.8.8','8.8.4.4']

device_hiera::network_interface:
  'Ethernet1':
    description: 'Engineering'

Use this configuration style for DRY configuration of devices with NetDev provider modules.

Configuring the Puppet Server

Before configuring the Cisco NX-OS device, install the puppetlabs/ciscopuppet module on a Puppet Server:

[vagrant@puppetserver ~]$ puppet module install puppetlabs/ciscopuppet
Notice: Install into /etc/puppetlabs/code/environments/production/modules ...
Notice: Downloading from https://forgeapi.puppetlabs.com ...
Notice: Installing -- do not interrupt ...
/etc/puppetlabs/code/environments/production/modules
└── puppetlabs-ciscopuppet (v1.0.0)

Preparing the NX-OS Device

The Puppet agent runs best in the Guest Shell environment. By default, the Guest Shell doesn’t have enough resources. Therefore, preparation requires that we resize the Guest Shell on each switch:

n3k# guestshell disable

n3k# guestshell resize rootfs 400
Note: Please disable/enable or reboot the Guest shell for rootfs to be resized

n3k# guestshell resize memory 300
Note: Please disable/enable or reboot the Guest shell for memory to be resized

n3k# guestshell enable
n3k# show guestshell detail
Virtual service guestshell+ detail
 State                 : Activated

    Resource reservation
    Disk                : 400 MB
    Memory              : 300 MB

The next step is to configure an IP address for the management interface, then the DNS resolver, and finally the NTP time service:

[root@guestshell]# config term
  interface mgmt0
    vrf member management
    ip address 192.168.1.21/24

  vrf context management
    ip domain-name example.com
    ip name-server 192.168.1.10
    ip name-server 192.168.1.11
    end

  ntp server 192.168.1.10 use-vrf management
end

The GuestShell environment is a secure Linux container running CentOS 7. This container has its own networking, which must be configured separately:

n3k# guestshell

[root@guestshell]# sudo su -
[root@guestshell]# chvrf management
[root@guestshell]# hostname nxswitch01
[root@guestshell]# echo 'nxswitch01' > /etc/hostname
[root@guestshell]# echo 'domain example.com' > /etc/resolv.conf
[root@guestshell]# echo 'search example.com' >> /etc/resolv.conf
[root@guestshell]# echo 'nameserver 192.168.1.10' >> /etc/resolv.conf
[root@guestshell]# echo 'nameserver 192.168.1.11' >> /etc/resolv.conf

Installing the NX-OS Puppet Agent

Install Puppet using a process eerily similar to what we’ve used throughout this book (that is correct—the Guest Shell uses the Enterprise Linux repository):

1. yum install http://yum.puppetlabs.com/puppetlabs-release-pc1-el-7.noarch.rpm
2. yum install puppet-agent

After installing Puppet on the NX-OS device, you’ll need to install some Ruby gems:

[root@guestshell]# gem install cisco_node_utils
[root@guestshell]# gem list | egrep 'cisco|net_http'
cisco_node_utils (1.0.0)
cisco_nxapi (1.0.0)
net_http_unix (0.2.1)

If you are running on a Highly Available (HA) platform, exit the Guest Shell and sync these changes to the backup processor:

n3k# guestshell sync

Enabling the NX-OS Puppet Agent

At this point, you have a complete Puppet v4 client installed on the NX-OS device. You configure it and authorize it exactly like any other Puppet agent on CentOS 7, as follows:

1. Run export PATH=/opt/puppetlabs/puppet/bin: /opt/puppetlabs/puppet/lib:$PATH.
2. Configure /etc/puppetlabs/puppet/puppet.conf with the server name.
3. Run puppet agent --test to connect to the server.
4. Sign the certificate request on the Puppet server if not using autosign.
5. Run the Puppet agent again to download and apply the catalog.
6. Run systemctl enable puppet.

It is necessary to edit the startup process prior to starting the agent. The following change ensures that Puppet runs in the NX-OS management namespace:

[root@guestshell]# sed -i.bak 
   -e 's#^ExecStart=#ExecStart=/bin/nsenter --net=/var/run/netns/management #' 
   /usr/lib/systemd/system/puppet.service

Finally, you can start the Puppet agent service:

[root@guestshell]# systemctl start puppet

If you are running on a Highly Available (HA) platform, exit the guestshell and sync these changes to the backup processor:

n3k# guestshell sync

Managing Configuration

Documentation for the NX-OS resources can be found on the Puppet Forge at “Cisco Puppet NX-OS devices: Resource Reference”.

I highly recommend that you make use of the device_hiera module documented in “Managing Network Devices with Puppet Device”. This module works equally well with devices that have an embedded Puppet agent, and will allow the configuration to be DRY.

For example, you may want to configure all the default OSPF instance name and cost. In the global common.yaml file, define these defaults:

device_hiera::resources:
  - cisco_interface_ospf

device_hiera::defaults::cisco_interface_ospf:
  ensure: present
  cost  : 200
  ospf  : default

Assign the device_hiera class and override these parameters as necessary within a specific device’s Hiera configuration data, such as hostname/switch01.yaml.

classes:
  - device_hiera

device_hiera::cisco_interface_ospf:
  'Ethernet1/2 default': 
    area: '172.16.0.0'

Supported Devices

Puppet is supported on modern EX, MX, and QFX switches and routers with Enterprise features enabled. The updated list of supported devices is documented on the Puppet Forge at juniper/netdev_stdlib_junos.

The Juniper device runs the Puppet agent. The agent utilizes the netdev library to translate Puppet configuration into netconf instructions the device can understand (see Figure 31-1).

Figure 31-1. Junos SDK: JPuppet overview

It would appear from the documentation that you could download the virtualized MX Series Universal Edge Router (vMX) free trial to set up a virtualized test lab. Documentation for the vMX platform and installation images can be downloaded from “vMX - Download Software” on the Juniper Support site.

Installing Modules on the Puppet Server

On the Puppet server, you will need to install the netconf RubyGem:

[vagrant@puppetserver ~]$ sudo puppetserver gem install netconf
Fetching: nokogiri-1.6.6.2-java.gem (100%)
Successfully installed nokogiri-1.6.6.2-java
Fetching: net-ssh-2.9.2.gem (100%)
Successfully installed net-ssh-2.9.2
Fetching: net-scp-1.2.1.gem (100%)
Successfully installed net-scp-1.2.1
Fetching: netconf-0.3.1.gem (100%)
Successfully installed netconf-0.3.1
4 gems installed

Then install the Junos Puppet module:

[vagrant@puppetserver ~]$ sudo puppet module install juniper-netdev_stdlib_junos
Notice: Preparing to install into environments/production/modules ...
Notice: Downloading from https://forgeapi.puppetlabs.com ...
Notice: Installing -- do not interrupt ...
/etc/puppetlabs/code/environments/production/modules
└─┬ juniper-netdev_stdlib_junos (v2.0.0)
  └── netdevops-netdev_stdlib (v1.0.0)

Preparing the Junos Device

Configure the management interface, DNS domain name, and NTP servers if that hasn’t been done already. All of these are necessary in order to communicate with Puppet Server:

root@junos> configure
[edit]
root@junos# set interfaces fxp0.0 family inet address 192.168.1.21/24
root@junos# set system host-name device-name
root@junos# set system domain-name example.com
root@junos# set system domain-search [ example.com example.net ]
root@junos# set system name-server 192.168.1.10
root@junos# set system name-server 192.168.1.11
root@junos# set system ntp time-zone America/Los_Angeles
root@junos# set system ntp server 192.168.1.10
root@junos# set system ntp server 192.168.1.11
root@junos# edit system extensions
[edit system extensions]
root@junos# set providers juniper license-type juniper deployment-scope commer
root@junos# commit and-quit
commit complete
root@junos>

This example is presented without explanation because we expect that you know the Junos configuration commands already.

Installing the Junos Puppet Agent

Download Puppet for Junos from https://downloads.puppetlabs.com/junos/. Select the version known to work with your platform, listed at juniper/netdev_stdlib_junos on the Puppet Forge. Copy this file to the /var/tmp directory on the device.

In this example, we’ll configure an EX4300 switch, which utilizes the PowerPC architecture. AFter downloading the appropriate Puppet version from the Juniper site, run this:

$ scp jpuppet-3.6.1_1.junos.powerpc.tgz junos-device:/var/tmp/

Log in to the device and install the software like any other Junos software package:

root@junos>request system software add /var/tmp/jpuppet-3.6.1_1.junos.powerpc.tgz

Creating the Puppet User

Create a puppet user on the device. This user account will be used by Puppet when configuring the device. Do not share this account with a real human being, or any other automation:

root@junos> configure
[edit]
root@junos# set system login user puppet class superuser
root@junos# set system login user puppet authentication plain-text-password'
New password: type a secure password
Retype new password: retype the password
root@junos# set system login user puppet password plain-text-password
root@junos# set system login user puppet shell csh
root@junos# commit and-quit
commit complete
root@junos>

Now log in to the device as the puppet user and create the following files and directories:

$ ssh puppet@junos-device
Password: password

puppet@junos> start shell csh
puppet@junos% echo "setenv PATH ${PATH}:/opt/jet/juniper/bin" >> $HOME/.cshrc
puppet@junos% echo "limit data 128M" >> $HOME/.cshrc
puppet@junos% mkdir -p $HOME/.puppet/var/run
puppet@junos% mkdir -p $HOME/.puppet/var/log
puppet@junos% vi $HOME/.puppet/puppet.conf

Create a Puppet configuration file like so:

[main]
    pluginsync = true
    libdir = $vardir/lib
    logdir = $vardir/log/puppet
    rundir = $vardir/run/puppet
    ssldir = $vardir/ssl

[agent]
    server = puppet.example.com

Save the file, then exit the shell and log out. Log in to the unit again in order to validate the environment:

puppet@junos% exit
puppet@junos> exit

$ ssh puppet@junos-device
Password: password

Start the shell and run the facter command to confirm that Puppet executables are in the PATH now:

puppet@junos> start shell csh
puppet@junos% facter
architecture => i386
domain => example.com
fqdn => junos-device.example.com
...snip...

Now connect to the server, just like any other Puppet agent:

1. Run puppet agent --test to connect to the server.
2. Sign the certificate request on the Puppet server if not using autosign.
3. Run the Puppet agent again to download and apply the catalog.

Adjusting Physical Interface Settings

The following example uses device_hiera with NetDev resources to configure physical interfaces on a Junos device.

The netdev_interface resource declares the attributes for a physical interface, such as speed, MTU, or duplex. As these tend to be consistent throughout a deployment, you may not need the custom configuration.

In the global common.yaml file, define defaults for physical interfaces:

device_hiera::resources:
  - netdev_device
  - netdev_interfaces

device_hiera::defaults::netdev_interface:
  # many are resource defaults we could leave out
  ensure: present
  active: 'true'
  admin : 'up'
  duplex: 'auto'
  speed : 'auto'
  mtu   : '1500'
 

Assign the device_hiera class and override these parameters as necessary within a specific host’s Hiera configuration data, such as hostname/switch01.yaml:

classes:
  - device_hiera

device_hiera::netdev_interfaces::ports:
  - 'ge-1/0/': '1-8'
  - 'ge-2/1/': '1-48'
 
device_hiera::netdev_interfaces::custom:
  'ge-1/0/13':
    description: 'bad port'
    enable     : 'false'
  'ge-4/0/1':
    description: 'External firewall interface'
    speed      : '100m'

This Hiera data will configure device_hiera to ensure that interface physical attributes are consistent on 56 ports, with a custom interface configuration on port ge-4/0/1. Port ge-1/0/13 is disabled with a comment explaining why.

Simplifying Layer-2 VLANs

The netdev_l2_interface resource declares the attributes for layer-2 switching services. It can reference VLANs created using netdev_vlan resources, or it can reference VLANs statically defined on the device.

In the global common.yaml file, define common defaults for VLANs, physical interfaces, and layer-2 interfaces. As VLANs are shared in this example deployment, we’ll place those in this common data:

device_hiera::resources:
  - netdev_device
  - netdev_l2_interfaces
  - netdev_vlan

device_hiera::defaults::netdev_vlan:
  active: 'true'
  ensure: 'present'

device_hiera::defaults::netdev_l2_interface:
  ensure       : present
  active       : true
  vlan_tagging : 'disable'
  untagged_vlan: 'corporate'

device_hiera::netdev_vlan:
  'corporate':
    vlan_id    : '100'
    description: 'Corporate Network'
  'hardware':
    vlan_id    : '101'
    description: 'Hardware Development'
  'testing':
    vlan_id    : '102'
    description: 'Test Network'
 

Assign the device_hiera class and override these parameters as necessary within a specific host’s Hiera configuration data, such as hostname/switch01.yaml:

classes:
  - device_hiera

device_hiera::netdev_l2_interfaces::ports:
  - 'ge-1/0/': '1-8'
  - 'ge-2/1/': '1-48'
 
device_hiera::netdev_l2_interfaces::custom:
  'ge-4/0/2':
    description: 'Uplink to core'
    vlan_tagging : 'enable'
    untagged_vlan: 'absent'
    tagged_vlans : ['corporate','hardware','testing']

This Hiera data will configure device_hiera to ensure the following:

• Default access port configuration on 56 ports on the first two slots
• A custom layer-2 trunking configuration on port ge-4/0/2

That’s 57 detailed port configurations in a dozen lines of text. It doesn’t get easier than this.

Enabling Link Aggregation

The netdev_lag resource declares the attributes for a link aggregation group (LAG), sometimes referred to as a port channel or bonded interface. The LAG can optionally enable the use of link aggregation control protocol (LACP) to maintain a peer relationship with the remote side.

In the global common.yaml file, define common defaults for VLANs, physical interfaces, and layer 2 interfaces. As VLANs are shared in this example deployment, we’ll place those in this common data:

device_hiera::resources:
  - netdev_device
  - netdev_lag
  - netdev_l2_interface

device_hiera::defaults::netdev_lag:
  lacp  : 'passive'

Assign the device_hiera class and override these parameters as necessary within a specific host’s Hiera configuration data, such as hostname/switch01.yaml:

classes:
  - device_hiera

device_hiera::netdev_lag:
  'ae0':
    links: ['ge-4/0/1', 'ge-4/0/2', 'ge-5/0/1', 'ge-5/0/2']

device_hiera::netdev_l2_interfaces::custom:
  'ae0:
    vlan_tagging : 'enable'
    tagged_vlans : ['corporate','hardware','testing']

This Hiera data will configure device_hiera to ensure the following:

• Bind four ports on two slots together as a bonded LACP port group.
• Configure three tagged VLANs on the newly created port group.

Short, simple, and easy to read.

Defining Ad Hoc Configuration Parameters

It is possible to apply Junos configuration statements for which there is no Puppet resource. For this purpose, you’ll need to create a Puppet module containing templates for the configuration:

[vagrant@puppetserver ~]$ puppet module generate myorg/junos_config
 …snip…
[vagrant@puppetserver ~]$ cd junos_config/
[vagrant@puppetserver ~]$ mkdir templates

Create ERB templates as documented in “Using Ruby ERB Templates”. These templates should resolve to a list of Junos configuration commands after parsing, like so:

set system domain-name example.com
set system domain-search [ example.com example.net ]
set system name-server 192.168.1.10
set system name-server 192.168.1.11
set system ntp time-zone America/Los_Angeles
set system ntp server 192.168.1.10
set system ntp server 192.168.1.11

Finally, create a manifest that makes use of the template:

netdev_stdlib_junos::apply_group { 'dns-ntp-servers':
  ensure        => present,
  active        => true,
  template_path => 'junos_config/dns-ntp-servers.erb',
}

Obviously, it would be smarter to pass in Puppet variables and iterate over arrays for maximum flexibility. We’ll leave this as an exercise for the reader. Some useful examples of configuring BGP can be found at Puppet + ERB Templates + Junos = Increased automation agility and flexibility.

Here’s an example manifest that uses of one of these templates. This template looks for a variable named $service to be defined with an array of system services to enable:

# only enable SSH and NetConf configuration
$services = [ [ 'netconf', 'ssh' ] ]

netdev_stdlib_junos::apply_group{ "services_group":
  ensure        => present,
  active        => 'true',
  template_path => 'netdev_stdlib_junos/services.set.erb',
}

Distributing Junos Event Scripts

It is possible to copy Junos SLAX scripts to devices and assign them as event handlers:

[vagrant@puppetserver production]$ cd modules/junos_config
[vagrant@puppetserver junos_config]$ mkdir files

Place the event script file in the files/ directory. Then declare a file resource to copy the file to the device:

file { '/var/db/scripts/event/checklogs.slax':
  ensure => file,
  owner  => 'puppet',
  group  => 'wheel',
  mode   => '0644',
  source => 'puppet:///files/junos_config/checklogs.slax'
}

After running Puppet, you should see the files installed on your Junos device, as shown here:

$ ssh puppet@junos-device
Password: password

puppet@junos> file list /var/db/scripts/event/

To make the Junos script run automatically based on event trigger, create a manifest that declares $policy and $event_script variables before making use of the event-options.xml.erb template:

# Files to copy
$event_script = ['checklogs.slax']

# Configure event policy
$policy = {
  'check_logs' => {
    'events'       => [ 'sshd_login_failed' ],
    'action'       => 'then',
    'event-script' => 'checklogs.slax',
  }
}

# Now apply the commands using the 'event-options' template
netdev_stdlib_junos::apply_group{ 'event_options_group':
  ensure        => present,
  active        => true,
  template_path => 'netdev_stdlib_junos/event-options.xml.erb',
}  

You can declare multiple policies in the $policy hash, and multiple files in the $event_script array. You can find a list of events to match with set event-options policy check_logs events.

Documentation for event scripts can be found at Junos Event Automation: Event Scripts and Event Policy

Running Puppet Automatically

To enable Puppet to update the device automatically, enable a cron schedule for Puppet to run. Add the following cron resource to your Juniper configuration module:

cron { 'puppet_agent':
  user        => 'puppet',
  environment => 'PATH=/bin:/usr/bin:/sbin:/usr/sbin:/opt/sbin:
                       /opt/bin:/opt/jet/juniper/bin:/opt/sdk/juniper/bin'
  command     => 'puppet agent --onetime --no-daemonize',
  minute      => '*/30',
}

Troubleshooting

The Junos Puppet agent logs its actions extensively, making it easy to audit Puppet changes:

• The agent logs all commit operations with the provided Puppet catalog version.
• Puppet logs include a Junos source indicator.
• The Puppet agent makes configuration changes under exclusive lock, preventing multiple agents or users from overlapping commits.

These features enable report extraction and problem isolation in production environments.

On some platforms, the netdev_device resource (and all other Junos resources) will fail to apply if the Puppet user account doesn’t have permission to configure the device, or if another user is interactively working in configuration mode. When this occurs, you’ll see an error like this:

err: JUNOS: configuration database locked by:
  jorhett terminal p0 (pid 6129) on since 2015-12-19 15:57:29 UTC
      exclusive {master:0}[edit]

To verify that the Puppet agent has downloaded and committed a specific catalog, use the show system commit operational mode command to view the commit history and catalog versions:

root@junos.example.com> show system commit
0   2015-12-19 10:50:17 PST by puppet via netconf
    Puppet agent catalog: 1359474609
1   2015-12-19 10:49:54 PST by jorhett via cli
2   2015-12-19 10:48:00 PST by puppet via netconf
    Puppet agent catalog: 1359474408
3   2015-12-19 06:47:37 PST by root via cli
4   2015-12-19 04:16:57 PST by puppet via netconf
    Puppet agent catalog: 1359474408