Resolv

Crystal CI GitHub release License

Resolv is a DNS resolver library in Crystal that supports UDP, TCP, and DoH (DNS-over-HTTPS).

Supported Resource Record (RR) TYPEs :

| | Type | Value | Meaning | Defining RFC | | - | ------- | ----- | ---------------------------------------- | ------------ | | ✓ | A | 1 | a host address | RFC 1035 | | ✓ | NS | 2 | an authoritative name server | RFC 1035 | | | MD | 3 | a mail destination (Obsolete - use MX) | RFC 1035 | | | MF | 4 | a mail forwarder (Obsolete - use MX) | RFC 1035 | | ✓ | CNAME | 5 | the canonical name for an alias | RFC 1035 | | ✓ | SOA | 6 | marks the start of a zone of authority | RFC 1035 | | | MB | 7 | a mailbox domain name (EXPERIMENTAL) | RFC 1035 | | | MG | 8 | a mail group member (EXPERIMENTAL) | RFC 1035 | | | MR | 9 | a mail rename domain name (EXPERIMENTAL) | RFC 1035 | | | NULL | 10 | a null RR (EXPERIMENTAL) | RFC 1035 | | | WKS | 11 | a well known service description | RFC 1035 | | ✓ | PTR | 12 | a domain name pointer | RFC 1035 | | | HINFO | 13 | host information | RFC 1035 | | | MINFO | 14 | mailbox or mail list information | RFC 1035 | | ✓ | MX | 15 | mail exchange | RFC 1035 | | ✓ | TXT | 16 | text strings | RFC 1035 | | ✓ | AAAA | 28 | IPv6 host address | RFC 3596 | | ✓ | SRV | 33 | service location | RFC 2782 | | ✓ | CAA | 257 | certification authority authorization | RFC 8659 |

Installation

  1. Add the dependency to your shard.yml:

    dependencies:
  resolv:
    github: mamantoha/resolv-crystal

  2. Run shards install

Usage

require "resolv"

dns = Resolv::DNS.new("8.8.8.8", read_timeout: 10.seconds, retry: 3, requester: :tcp)

dns.resources("crystal-lang.org", :a)
# #<Resolv::DNS::Resource::A:0x1010d0c40 @address="18.66.112.124">

dns.mx_resources("gmail.com")
# #<Resolv::DNS::Resource::MX:0x1010d0560 @preference=40, @exchange="alt4.gmail-smtp-in.l.google.com">

dns.soa_resources("gmail.com")
# => #<Resolv::DNS::Resource::SOA:0x10245c100 @mname="ns1.google.com", @rname="dns-admin.google.com", @serial=646797294, @refresh=900, @retry=900, @expire=1800, @minimum=60>

dns.srv_resources("_xmpp-client._tcp.jabber.org")
# #<Resolv::DNS::Resource::SRV:0x74689eebdf60 @priority=30, @weight=30, @port=5222, @target="zeus.jabber.org">

dns = Resolv::DNS.new("dns.toys")
dns.txt_resources("lviv.weather")
# #<Resolv::DNS::Resource::TXT:0x104cf00a0 @txt_data=["Lviv (UA)", "28.00C (82.40F)", "43.90% hu.", "partlycloudy_day", "14:00, Thu"]>

Alternatives

Other alternatives are:

Contributing

  1. Fork it (https://github.com/mamantoha/resolv-crystal/fork)
  2. Create your feature branch (git checkout -b my-new-feature)
  3. Commit your changes (git commit -am 'Add some feature')
  4. Push to the branch (git push origin my-new-feature)
  5. Create a new Pull Request

Contributors