def _update_dns_hostnames()

in src/slurm_plugin/instance_manager.py [0:0]

• 35 lines of code
• 10 McCabe index (conditional complexity)

    def _update_dns_hostnames(self, nodes, update_dns_batch_size=500):
        logger.info(
            "Updating DNS records for %s - %s",
            self._hosted_zone,
            self._dns_domain,
        )
        if not self._hosted_zone or not self._dns_domain:
            logger.info(
                "Empty DNS domain name or hosted zone configuration parameter",
            )
            return

        changes = []
        for hostname, instance in nodes.items():
            changes.append(
                {
                    "Action": "UPSERT",
                    "ResourceRecordSet": {
                        "Name": f"{hostname}.{self._dns_domain}",
                        "ResourceRecords": [{"Value": instance.private_ip}],
                        "Type": "A",
                        "TTL": 120,
                    },
                }
            )

        if changes:
            # Submit calls to change_resource_record_sets in batches of max 500 elements each.
            # change_resource_record_sets API call has limit of 1000 changes,
            # but the UPSERT action counts for 2 calls
            # Also pick the number of retries to be the max between the globally configured one and 4.
            # This is done to address Route53 API throttling without changing the configured retries for all API calls.
            configured_retry = self._boto3_config.retries.get("max_attempts", 0) if self._boto3_config.retries else 0
            boto3_config = self._boto3_config.merge(
                Config(retries={"max_attempts": max([configured_retry, 4]), "mode": "standard"})
            )
            route53_client = boto3.client("route53", region_name=self._region, config=boto3_config)
            changes_batch_size = min(update_dns_batch_size, 500)
            for changes_batch in grouper(changes, changes_batch_size):
                route53_client.change_resource_record_sets(
                    HostedZoneId=self._hosted_zone, ChangeBatch={"Changes": list(changes_batch)}
                )