Resolves the given hostname to a DNS record.
This is an asynchronous function that returns a Promise
.
Syntax
var resolving = browser.dns.resolve(
hostname, // string
flags // array of string
)
Parameters
hostname
string
. The hostname to resolve.flags
Optionalarray
ofstring
. Flags to modify the way the hostname is resolved. Any omitted flags default tofalse
. You can pass zero or more of the following flags:-
"allow_name_collisions"
: Allow name collision results which are normally filtered out."bypass_cache"
: Suppresses the internal DNS lookup cache."canonical_name"
: The canonical name of the specified host will be queried."disable_ipv4"
: Only IPv6 addresses will be returned."disable_ipv6"
: Only IPv4 addresses will be returned."disable_trr"
: Do not use the Trusted Recursive Resolver (TRR) for resolving the host name. A TRR enables resolving of host names using a dedicated DNS-over-HTTPS server."offline"
: Only literals and cached entries will be returned."priority_low"
: The request is given lower priority. If "priority_medium" is also given, the query is given medium priority."priority_medium"
: The request is given medium priority. If "priority_low" is also given, the query is given medium priority."speculate"
: Indicates that the request is speculative. Speculative requests return errors if prefetching is disabled by the browser's configuration.
Return value
A Promise
that will be fulfilled with a DNSRecord
object. This object can contain the following properties:
addresses
array
ofstring
. The IP addresses associated with this DNS record.canonicalName
string
. The canonical name for this record. This is only included in the response if the"canonical_name"
flag was passed toresolve()
.isTRR
boolean
:true
if the record was retrieved using a Trusted Recursive Resolver (TRR).
Browser compatibility
BCD tables only load in the browser
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
Examples
function resolved(record) {
console.log(record.addresses);
}
let resolving = browser.dns.resolve("example.com");
resolving.then(resolved);
// > e.g. Array [ "73.284.240.12" ]
Bypass the cache, and ask for the canonical name:
function resolved(record) {
console.log(record.canonicalName);
console.log(record.addresses);
}
let resolving = browser.dns.resolve("developer.mozilla.org",
["bypass_cache", "canonical_name"]);
resolving.then(resolved);
// > e.g. xyz.us-west-2.elb.amazonaws.com
// > e.g. Array [ "78.18.187.134", "34.79.135.234" ]