diff options
Diffstat (limited to 'content/blog/2022-06-04-njalla-dns-api.md')
| -rw-r--r-- | content/blog/2022-06-04-njalla-dns-api.md | 211 |
1 files changed, 0 insertions, 211 deletions
diff --git a/content/blog/2022-06-04-njalla-dns-api.md b/content/blog/2022-06-04-njalla-dns-api.md deleted file mode 100644 index 34fb680..0000000 --- a/content/blog/2022-06-04-njalla-dns-api.md +++ /dev/null @@ -1,211 +0,0 @@ -+++ -date = 2022-02-10 -title = "Dynamic DNS with Njalla API" -description = "Learn how to dynamically update DNS records for changing IPs with Njalla." -+++ - -## Njalla's API - -As noted in my recent post about [switching to Njalla from -Cloudflare](/blog/ditching-cloudflare/), I was searching for a -way to replace my very easy-to-use bash script to [update Cloudflare's -DNS via their API](/blog/cloudflare-dns-api/). - -To reiterate what I said in those posts, this is a common necessity for -those of us who have non-static IP addresses that can change at any -moment due to ISP policy. - -In order to keep a home server running smoothly, the server admin needs -to have a process to constantly monitor their public IP address and -update their domain's DNS records if it changes. - -This post explains how to use Python to update Njalla's DNS records -whenever a machine's public IP address changes. - -### Creating a Token - -To use Njalla's API, you will first need to create a token that will be -used to authenticate you every time you call the API. Luckily, this is -very easy to do if you have an account with Njalla. - -Simply go the [API Settings](https://njal.la/settings/api/) page and -click the `Add Token` button. Next, enter a name for the -token and click `Add`. - -Finally, click the `Manage` button next to your newly created -token and copy the `API Token` field. - -### Finding the Correct API Request - -Once you have a token, you're ready to call the Njalla API for any -number of requests. For a full listing of available requests, see the -[Njalla API Documentation](https://njal.la/api/). - -For this demo, we are using the `list-records` and -`edit-record` requests. - -The `list-records` request requires the following payload to -be sent when calling the API: - -```txt -params: { - domain: string -} -``` - -The `edit-record` request requires the following payload to -be sent when calling the API: - -```txt -params: { - domain: string - id: int - content: string -} -``` - -## Server Set-Up - -To create this script, we will be using Python. By default, I use Python -3 on my servers, so please note that I did not test this in Python 2, -and I do not know if Python 2 will work for this. - -### Creating the Script - -First, find a suitable place to create your script. Personally, I just -create a directory called `ddns` in my home directory: - -```sh -mkdir ~/ddns -``` - -Next, create a Python script file: - -```sh -nano ~/ddns/ddns.py -``` - -The following code snippet is quite long, so I won't go into depth on -each part. However, I suggest you read through the entire script before -running it; it is quite simple and contains comments to help explain -each code block. - -:warning: **Note**: You will need to update the following variables for -this to work: - -- `token`: This is the Njalla API token you created - earlier. -- `user_domain`: This is the top-level domain you want to - modify. -- `include_subdomains`: Set this to `True` if - you also want to modify subdomains found under the TLD. -- `subdomains`: If `include_subdomains` = - `True`, you can include your list of subdomains to be - modified here. - -```python -#!/usr/bin/python -# -*- coding: utf-8 -*- -# Import Python modules - -from requests import get -import requests -import json - -# Set global variables - -url = 'https://njal.la/api/1/' -token = '<your-api-token>' -user_domain = 'example.com' -include_subdomains = True -subdomains = ['one', 'two'] - - -# Main API call function - -def njalla(method, **params): - headers = {'Authorization': 'Njalla ' + token} - response = requests.post(url, json={'method': method, - 'params': params}, headers=headers).json() - if 'result' not in response: - raise Exception('API Error', response) - return response['result'] - - -# Gather all DNS records for a domain - -def get_records(domain): - return njalla('list-records', domain=user_domain) - - -# Update a DNS record for a domain - -def update_record(domain, record_id, record_content): - return njalla('edit-record', domain=domain, id=record_id, - content=record_content) - - -# Get public IP addresses - -ipv4 = get('https://api.ipify.org').text -print('IPv4: {}'.format(ipv4)) -ipv6 = get('https://api64.ipify.org').text -print('IPv6: {}'.format(ipv6)) - -# Call API to get all DNS records - -data = get_records(user_domain) - -# Loop through records and check if each one is IPv4 (A) or IPv6 (AAAA) -# Update only if DNS is different from server IP - -for record in data['records']: - if record['name'] == '@' or (include_subdomains and record['name'] \ - in subdomains): - if record['type'] == 'A': - if record['content'] == ipv4: - print(record['type'], 'record for', record['name'], - 'already matches public IPv4 address. Skipping...' - ) - else: - print('IPv4 of', ipv4, - 'does not match Njalla's value of', - record['content'], '. Updating...') - update_record(user_domain, record['id'], ipv4) - elif record['type'] == 'AAAA': - if record['content'] == ipv6: - print(record['type'], 'record for', record['name'], - 'already matches public IPv6 address. Skipping...' - ) - else: - print('IPv6 of', ipv6, - 'does not match Njalla's value of', - record['content'], '. Updating...') - update_record(user_domain, record['id'], ipv6) -``` - -### Running the Script - -Once you've created the script and are ready to test it, run the -following command: - -```sh -python3 ~/ddns/ddns.py -``` - -### Setting the Script to Run Automatically - -To make sure the scripts run automatically, add it to the -`cron` file so that it will run on a schedule. To do this, -open the `cron` file: - -```sh -crontab -e -``` - -In the cron file, paste the following at the bottom of the editor in -order to check the IP every five minutes: - -```sh -*/5 * * * * python3 /home/<your_username>/ddns/ddns.py -``` |