R53.py - Command Line Route 53 interface with Dynamic DNS support

This Python 3.7+ script does simple management of Route 53 zones and records using the AWS API. You must have the AWS CLI properly configured with a credentials file containing valid AWS keys. The script supports use of profiles if you have multiple key sets configured properly.

The script trivially does dynamic DNS using the "--myip" parameter to look up its own public IP and use it to update an A record.

The script can also set an A record to an EC2 instance's public IP address, even if the instance is in a different region.

COMMAND LINE HELP

usage: r53 [-h] [--profile PROFILE] [--region REGION] [--delete]
           [--list-hosted-zones] [--zone ZONE] [--name NAME]
           [--type {A,AAAA,CAA,CNAME,MX,NAPTR,SPF,SRV,TXT}] [--ttl TTL]
           [--value VALUE] [--eip EIP] [--myip] [--instanceid INSTANCEID]

Manage resource records in AWS Route 53

optional arguments:
  -h, --help            show this help message and exit
  --profile PROFILE     Use a specific named profile in AWS configuration
  --region REGION       target AWS API calls against a specific region where
                        applicable
  --delete              delete a resource record from a zone
  --list-hosted-zones   list all hosted zones
  --zone ZONE           DNS name of target zone
  --name NAME           name of resource record
  --type {A,AAAA,CAA,CNAME,MX,NAPTR,SPF,SRV,TXT}
                        resource record type
  --ttl TTL             TTL (in seconds)
  --value VALUE         value to set in resource record
  --eip EIP             EIP allocation ID; sets value to the EIP address. Type
                        and value parameters are ignored if EIP is specified.
  --myip                sets value to the calling computers public IP address.
                        Type and value parameters are ignored if myip is
                        specified.  Local IP is looked up at https://checkip.amazonaws.com
  --instanceid INSTANCEID
                        EC2 instance ID; sets value to the public IP address
                        of the instance. Type and value parameters are ignored
                        if instanceid is specified.

SETUP

1. Install the AWS command line interface (CLI)

   • https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-install.html

2. Configure the AWS CLI

   You could install the AWS CLI and use "aws configure":

   • https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-getting-started.html

   or do it manually:

   • Credentials & configuration: https://docs.aws.amazon.com/cli/latest/userguide/cli-config-files.html
   • Profiles: https://docs.aws.amazon.com/cli/latest/userguide/cli-multiple-profiles.html

3. Permissions

   The following AWS permissions are required; set them using IAM policy on the IAM user or role you're using.

   • ec2:DescribeInstances
   • route53:ListHostedZones
   • route53:ListResourceRecordSets
   • route53:ChangeResourceRecordSets

4. Configure your Python environment

   You must install argparse and boto3 in the python 3.7+ environment where you're going to run the script:

   pip install argparse
   pip install boto3
   

   Alternatively, just

   pip install -r requirements.txt
   

USING THE SCRIPT

The script tries to infer as much information as possible:

• If no zone is specified, the script attempts to list hosted zones.
• If only a zone and a record name are specified, the script attempts to look up and display matching records.
• If a new value is provided for the record itself or for the TTL, the script attempts to upsert (add or update) the record.
• Deletes explicitly require the --delete option.
• Type is optional if the type can be cleanly inferred from the value and the value is correctly formatted (e.g. A, AAAA or CNAME).

EXAMPLES

r53 --help                                              # the above text
r53                                                     # list hosted zones
r53 --zone example.com --name test                      # display all records with name test in zone example.com
r53 --zone example.com --name test --type A --delete    # type is required for delete
r53 --zone example.com --name test --myip               # create/update an A record named test using your ip
                                                          (i.e. dynamic DNS)
r53 --zone example.com --name test --eip <eip-id>       # create/update an A record for an EIP
r53 --zone example.com --name test --instanceid i-123   # create/update an A record for the public IP addr of
                                                          an instance
r53 --zone example.com --name test --value 1.2.3.4      # create/update an A record (--type A is optional as
                                                          IPv4 implies A)
r53 --zone example.com --name test --value ::1          # create/update an AAAA record (--type AAAA is optional
                                                          as IPv6 implies AAAA)
r53 --zone example.com --name test --value foo.bar.com  # create/update a CNAME record (--type CNAME is optional
                                                          as hostname implies CNAME)
r53 --profile profilename ...                           # use the keys and configuration from the profilename
                                                          profile in ~/.aws/credentials
r53 --region us-east-1 ...                              # override the region specified in .aws configuration
                                                          (where is your instance?)

NOTES

The script doesn't support aliases or weighting. It doesn't support management of zones. It doesn't support all record types that Route53 supports. It doesn't do a lot of error checking, expecting boto to throw useful exceptions.

TROUBLESHOOTING

botocore InvalidClientTokenId - this means that your credentials are wrong or missing. Set up new a new key pair with IAM.

DYNAMIC DNS

To implement dynamic DNS without subscribing to one of the public DDNS providers:

1. Register a domain (e.g. "mydomain.com") and host it with Route 53

2. Configure this tool as described above in "SETUP"

3. Choose a record name to use for DDNS, e.g. "home" ("home.mydomain.com").

4. Configure the tool to run regularly to create and update that A record with your IP address. Run this regularly from a computer behind that IP address, e.g. on a home server using a CRON job.

r53 --zone example.com --name home --myip