Ansible Blocks with Nested When Statements

inventory.yml

all: hosts: device1: interfaces: GigabitEthernet0: description: Internet Uplink GigabitEthernet0/0/0: GigabitEthernet0/0/1:

playbook.yml

--- - name: Main Play hosts: all gather_facts: false vars: ansible_connection: network_cli ansible_network_os: ios tasks: - name: Gather facts cisco.ios.ios_facts: gather_subset: all - name: Configure Interfaces when: interfaces is defined block: - name: Set interface descriptions loop: "{{ interfaces | dict2items }}" when: item.value.description is defined cisco.ios.ios_config: lines: - "description {{ item.value.description }}" parents: "interface {{ item.key }}"

Python For Loops with Complex Values

 I found myself needing to loop through a dictionary that looked like this:

data = {
    'key1': ['id1', 'subnet1'],
    'key2': ['id2', 'subnet2'],
    'key3': ['id3', 'subnet3']
}

Normally, I'd do this:

for key, v in data.items():
  id = v[0]
  subnet = v[1]
  print(f"{key}: {id} {subnet}")

But today I figured I'd let AI suggest an efficiency and it came through. Instead of the above, I can do just this:

for key, (id, subnet) in data.items():
  print(f"{key}: {id} {subnet}")

Using SSH on Windows with Powershell

I've come to prefer CLIs over GUIs. Rather than install Putty (or grab the portal version and copy it to the server I want to use), I prefer to SSH directly from Powershell since Microsoft started including a client in the Windows Features.

First, make sure it's installed. From a Powershell prompt running with elevated privileges:

if (-not (Get-WindowsCapability -Online | Where-Object { $_.Name -like 'OpenSSH.Client*' -and $_.State -eq 'Installed' })) {
    Add-WindowsCapability -Online -Name OpenSSH.Client~~~~0.0.1.0
}

This will check if the SSH client is installed and if not, it will install it. 

Using SSH is pretty much the same as it is on Linux then:

ssh <username>@<hostname/fqdn/ip> -p <port>

However, if you do that, you'll be prompted for the password of the user. You could enable key based login, which would essentially use a huge alternate password stored in a file on your computer to connect to the target. 

First make sure your system has a key. If you already have keys, this will overwrite them, so use carefully. You can always change the name to something unique to make sure it doesn't get overwritten. Just update the name in the rest of the commands here. It's the same command on both Linux and Windows.

ssh-keygen -f ~/.ssh/id_rsa -b 4096 -N ""

For Linux

ssh-copy-id -i ~/.ssh/id_rsa.pub -p 22 <username>@<hostname/fqdn/ip>

For Windows

type ~\.ssh\id_rsa.pub | ssh <username>@<hostname/fqdn/ip> "cat >> ~/.ssh/authorized_keys"

Now you should be able to SSH from Powershell using the same command above:

ssh <username>@<hostname/fqdn/ip> -p <port>

Except that now, the client in Powershell will attempt to pass your key to the target to authenticate with. Since you key contains a super-long alternate password, you will be logged in. One cool thing is that this survives password changes on the target account.