Add a domain resolve test tool

[ElTopo]

Prerequisites

• I have checked the Wiki and Discussions and found no answer

• I have searched other issues and found no duplicates

• I want to request a feature or enhancement and not ask a question

The problem

As of version v0.107.55, AdGuard Home does not have a domain resolve tool on its web page.

Although we can use other DNS query tools, such as nslookup or dig, to check the result of the queries, we always want more information of AdGuard Home as DNS server, such as if the questioned domain is blocked, or in user's custom filter list, etc. These extra info is very useful for debugging or checking AGH.

Proposed solution

Add a domain resolve test tool somewhere at AdGuard Home web page that user can input a domain name and optional "client (from persistent clients)", tap on button "Resolve Test", AdGuard Home then queries the domain name, following the generic rule or as a request from one of Persistent clients, and prints result:

• if the domain name is blocked, also prints out the first blocklist that blocks the domain name (or maybe all blocklists that have this domain name blocked), or the first custom filter rule that blocks it;
• if the domain name is successfully queried, also prints the upstream DNS server, and the DNS rewrite rule if it's rewritten, and the allowlist if it's allowed from that list;
• if the domain name query failed, also prints reason (offline from the internet, upstream server times out, or upstream server reports "unknown domain name", etc.)

Alternatives considered and additional information

No response

[Dynamic5912]

You can do this in the custom filtering rule page.

[ElTopo]

@Dynamic5912 The one in "Custom filtering rules" page only tells you if the domain name is found in your custom filtering lists or not, it never checked other blocklists/allowlists, and never actually tried to resolve the name.

[Dynamic5912]

It also checks blocklists and reports what list it's found in

[ElTopo]

@Dynamic5912 I stand corrected with the blocklist part, however, it still lacks info about allowed domain names.

[Dynamic5912]

It also checks in allow lists and custom filtering rules that allow domains.