Merge native configurations (IOS)

In our previous example we merged two objects that already complied with the openconfig models. In this example, we are going to merge to native configurations.

Let’s start by loading the driver as usual:

from ntc_rosetta import get_driver

ios = get_driver("ios", "openconfig")
ios_processor = ios()

Now we are going to load a file with the “running” configuration:

with open("data/ios/config.txt", "r") as f:
    running_config = f.read()

And now a different file with the “candidate” config:

with open("data/ios/new_config.txt", "r") as f:
    candidate_config = f.read()

Let’s see the files side by side highlighting the differences:

!diff -y data/ios/config.txt data/ios/new_config.txt

interface FastEthernet1                                         interface FastEthernet1
   description This is Fa1                                         description This is Fa1
   shutdown                                                        shutdown
   exit                                                            exit
!                                                               !
interface FastEthernet1.1                                       interface FastEthernet1.1
   description This is Fa1.1                                       description This is Fa1.1
   exit                                                            exit
!                                                               !
interface FastEthernet1.2                                       interface FastEthernet1.2
   description This is Fa1.2                                       description This is Fa1.2
   exit                                                            exit
!                                                               !
interface FastEthernet3                                         interface FastEthernet3
   description This is Fa3                                         description This is Fa3
   no shutdown                                                     no shutdown
   switchport mode access                                          switchport mode access
   switchport access vlan 10                                       switchport access vlan 10
   exit                                                            exit
!                                                               !
interface FastEthernet4                                         interface FastEthernet4
   shutdown                                                        shutdown
   switchport mode trunk                                           switchport mode trunk
   switchport trunk allowed vlan 10,20                             switchport trunk allowed vlan 10,20
   exit                                                            exit
!                                                               !
vlan 10                                                         vlan 10
   name prod                                                       name prod
   no shutdown                                                |    shutdown
   exit                                                            exit
!                                                               !
vlan 20                                                       | vlan 30
   name dev                                                   |    name staging
   shutdown                                                   |    no shutdown
   exit                                                            exit
!                                                               !

As you can see vlan 20 is gone, vlan 10 has been suspended and there is a new vlan 30.

Now let’s parse those configurations as we did in our first tutorial:

parsed_candidate = ios_processor.parse(native={"dev_conf": candidate_config})
parsed_running = ios_processor.parse(native={"dev_conf": running_config})

Now that we have parsed both native configurations, doing a merge operation is identical as in our previous tutorial:

config = ios_processor.merge(
    candidate=parsed_candidate.raw_value(),
    running=parsed_running.raw_value()
)
print(config)

no vlan 20
vlan 10
   shutdown
   exit
!
vlan 30
   name staging
   no shutdown
   exit
!