Inspect Data Structures in Transformed Lab Topology¶

netlab inspect prints data structures in transformed lab topology (usually stored in netlab.snapshot.yml) created by netlab create command. You can display data in YAML or JSON format, and select a subset of data from the transformed topology or from an individual node.

When selecting data from an individual node, netlab adds group variables to node data, effectively displaying what you would see in the Ansible inventory.

Note

netlab inspect command is replicating the functionality of netlab create -o yaml:expression command with a more convenient user interface.

Usage¶

usage: netlab inspect [-h] [--snapshot [SNAPSHOT]] [--node NODE] 
                      [--format {yaml,json}] [expr]

Inspect data structures in transformed lab topology

positional arguments:
  expr                  Data selection expression

options:
  -h, --help            show this help message and exit
  --snapshot [SNAPSHOT]
                        Transformed topology snapshot file
  --node NODE           Display data for selected node(s)
  --format {yaml,json}  Select data presentation format

Topology Inspection Examples¶

To display this information…	…use this command
whole transformed topology	`netlab inspect`
node data	`netlab inspect nodes`
address pools	`netlab inspect addressing`

You can inspect any subset of the lab topology, for example:

To display this information…	…use this command
device data for device `eos`	`netlab inspect defaults.devices.eos`
valid attributes for the BGP module	`netlab inspect defaults.bgp.attributes`

Finally, the data selection argument is evaluated as a Python expression, so you can display most things that can be expressed as a one-line expression (don’t forget to quote the expression):

To display this information…	…use this command
node names	`netlab inspect 'list(nodes.keys())'`

Node Inspection Examples¶

You can use the --node parameter to inspect the data structure of a single node, a list of nodes (separated by commas), or a wildcard expression.

To display this information…	…use this command
data for node `r1`	`netlab inspect --node r1`
interface data for node `r1`	`netlab inspect --node r1 interfaces`
first interface on node `r1`	`netlab inspect --node r1 'interfaces[0]'`
BGP parameters on R1 and R2	`netlab inspect --node r1,r2 bgp`
VRFs on all nodes	`netlab inspect --node '*' vrfs`

Warning

You can use Python expressions only when specifying a single node to inspect.

Node data includes Ansible group variables, for example:

$ netlab inspect --node r1
af:
  ipv4: true
ansible_connection: network_cli
ansible_host: 192.168.121.101
ansible_network_os: eos
ansible_ssh_pass: vagrant
ansible_user: vagrant
box: arista/veos
...

Data from multiple nodes is shown in a tabular format, for example:

$ netlab inspect --node r1,r2 loopback
┏━━━━━━━━━━━━━━━━━━━━━━━━━┳━━━━━━━━━━━━━━━━━━━━━━━━━┓
┃ r1                      ┃ r2                      ┃
┡━━━━━━━━━━━━━━━━━━━━━━━━━╇━━━━━━━━━━━━━━━━━━━━━━━━━┩
│ ifindex: 0              │ ifindex: 0              │
│ ifname: Loopback0       │ ifname: Loopback0       │
│ ipv4: 10.0.0.1/32       │ ipv4: 10.0.0.2/32       │
│ neighbors: []           │ neighbors: []           │
│ type: loopback          │ type: loopback          │
│ virtual_interface: true │ virtual_interface: true │
└─────────────────────────┴─────────────────────────┘