ef18404448
Brings azure to parity with route53, which already exposes a refresh directive to control how often zones are re-synced. azure currently hardcodes this to 1 minute (Run calls h.run(ctx, time.Minute)) with no way to change it, even though the internal run() method already takes an arbitrary interval parameter - the plumbing exists, it just wasn't exposed as a Corefile option. Adds a refresh field to the Azure struct, threads it through New(), and has Run() use h.refresh instead of the hardcoded value. Parses the refresh directive in parse() mirroring route53's exact validation (accepts a plain number as seconds or a duration string, must be greater than 0). Extends TestSetup with refresh coverage (valid duration, valid plain number, missing arg, non-numeric, zero, negative). Verified it fails without the setup.go change (unknown property error) and passes with it. Signed-off-by: stackedbyaradhya <aradhyaj736@gmail.com>
azure
Name
azure - enables serving zone data from Microsoft Azure DNS service.
Description
The azure plugin is useful for serving zones from Microsoft Azure DNS. The azure plugin supports all the DNS records supported by Azure, viz. A, AAAA, CNAME, MX, NS, PTR, SOA, SRV, and TXT record types. NS record type is not supported by azure private DNS.
Zone data is loaded asynchronously after startup and refreshed every minute by default,
configurable via refresh. An unavailable zone or zone-listing error is logged without
preventing CoreDNS from starting or other configured zones from being updated. Each zone
listing, including retries and pagination, has a one-minute timeout.
Configuration and credential initialization errors still prevent startup.
Until a zone has been successfully loaded, queries for it return SERVFAIL unless
fallthrough is explicitly configured. Only complete, successful updates replace
the in-memory zone. Failed updates, including a deleted Azure zone returning an
error, retain the last successfully loaded data and are retried. Remove the zone
from the Corefile to stop serving this retained data. Snapshots are not persisted
across restarts or configuration reloads.
Syntax
azure RESOURCE_GROUP:ZONE... {
tenant TENANT_ID
client CLIENT_ID
secret CLIENT_SECRET
subscription SUBSCRIPTION_ID
environment ENVIRONMENT
fallthrough [ZONES...]
access private
refresh DURATION
}
-
RESOURCE_GROUP:ZONE is the resource group to which the hosted zones belongs on Azure, and ZONE the zone that contains data.
-
CLIENT_ID and CLIENT_SECRET are the credentials for Azure, and
tenantspecifies the TENANT_ID to be used. SUBSCRIPTION_ID is the subscription ID. All of these are needed to access the data in Azure. -
environmentspecifies the Azure ENVIRONMENT. -
fallthroughIf zone matches and no record can be generated, pass request to the next plugin. If ZONES is omitted, then fallthrough happens for all zones for which the plugin is authoritative. -
accessspecifies if the zone ispublicorprivate. Default ispublic. -
refreshcan be used to control how long between record retrievals from Azure DNS. It requires a duration string as a parameter to specify the duration between update cycles. Each update cycle may result in many Azure API calls depending on how many domains use this plugin and how many records are in each. Adjusting the update frequency may help reduce the potential of API throttling by Azure. If not provided the default refresh is 1 minute.
Examples
Enable the azure plugin with Azure credentials for private zones example.org, example.private:
example.org {
azure resource_group_foo:example.org resource_group_foo:example.private {
tenant 123abc-123abc-123abc-123abc
client 123abc-123abc-123abc-234xyz
subscription 123abc-123abc-123abc-563abc
secret mysecret
access private
}
}
See Also
The Azure DNS Overview.