nornir_csv
Use CSV files as a Nornir Inventory source with hosts, groups and defaults. This can be used as an equivalent to the Simple Inventory plugin but using CSV files instead of YAML. This does not generate any new files, but instead reads host data from three files:
- hosts.csv
- groups.csv
- defaults.csv
Installation
As of right now, the code hasn’t been published to PyPi, so it must be installed from source. Be sure to clone the repository locally:
cd /directory/where/you/clone/git/stuff/
git clone https://github.com/matman26/nornir_csv.git
The nornir_csv directory can then be copied to your project root and added as an external library.
cp nornir_csv/nornir_csv /destination/project/root
Usage
Since this is an external plugin for Nornir 3.0+, it must be registered before usage. The main project file must therefore contain something similar to:
from nornir import InitNornir
from nornir_csv.plugins.inventory.csv_inventory import CsvInventory
from nornir.core.plugins.inventory import InventoryPluginRegister
InventoryPluginRegister.register("CsvInventoryPlugin", CsvInventory)
nr = InitNornir(config_file='sample_config.yaml')
By default, the plugin will look for the files hosts.csv, groups.csv and defaults.csv inside the ./inventory/ directory, but the directory can be changed by specifying the plugin option inventory_dir_path. A sample file such as below can be used:
inventory:
plugin: CsvInventoryPlugin
options:
inventory_dir_path: /path/to/inventory/dir/
runner:
plugin: threaded
options:
num_workers: 20
The name of the csv files to be read for hosts, groups and defaults can also be customized by setting the options hosts_file, groups_file and defaults_file, respectively. These should correspond to the file’s basenames (no paths) with extension, if any.
CSV Syntax
Hosts
The hosts_file follows a specific syntax to make it nornir-compatible, see sample below:
name,hostname,username,password,port,platform,groups,custom_var
R1,192.168.122.10,cisco,cisco,22,cisco_ios,core main,foo
R2,192.168.122.20,cisco,cisco,22,cisco_xr,,bar
Note that name, hostname, username, password, port, platform and groups are nornir base attributes. This means they are hosts attributes directly, such that
nr.inventory.hosts['R1'].password
will yield the return value of ‘cisco’ as expected. Any custom variables that are added will be put inside the ‘data’ dictionary on the target host. So
nr.inventory.hosts['R1'].data['custom_var']
will return ‘foo’.
Notice also that to specify the list of groups to which a host belongs the list must be specified one group at a time, separated by spaces. In the csv above, R1 belongs to the groups ‘core’ and ‘main’. A hosts file is mandatory.
Groups
The groups_file is optional. It can be used to set default values for the base attributes of each host (for example, if every host of the same group uses the same credentials). Any attributes that are non-base attributes will be added to the ‘data’ container inside the generated group, similar to how it behaves with hosts. If no groups are specified in the csv file, hosts can still be assigned to groups but these will hold no data.
name,username,password,dns_server
core,cisco,cisco,8.8.8.8
main,,,,
Notice that the groups csv does not have any mandatory fields other than name.
Defaults
The defaults_file specifies any default variables. This file is also free-form, but is only composed of two lines: a header with the name of the variable and a second line with its value. The defaults file is optional.
message_of_the_day,foo,port
hello world!,bar,22
