dug

Name resolution aggregator

Synopsis

Usage: dug [OPTIONS] <HOSTNAMES>...

Options

The following options are available:

Arguments:
  [HOSTNAMES]...

Options:

    -a, --ascii    Format results as simple ASCII text
    -j, --json     Format results as structured JSON text
    -h, --help     Print help
    -V, --version  Print version

Description

dug is designed to be an exhaustive name lookup tool, looking up the given hostname(s) using any method available in the tool or on the system.

Some methods/sources used are:

• The local host's configured resolver
  • e.g., gethostname(3), gethostbyname(3), getnameinfo(3), etc.
• Major public DNS resolvers:
  • Cloudflare
  • Google
  • Quad9
• A simulated nslookup
  • Works by parsing /etc/resolv.conf (if present) and querying the hosts found.
  • May be significantly different from OS-based resolution.

dug will also use external utilities such as dig (from BIND9) or drill (from ldns) if found on the $PATH.

Resolvers are tried concurrently where possible, and results are aggregated in either a pretty-printed ASCII view, or as JSON output suitable for consumption by jq. See the Options for more info.

Installation

Build from source

If you already have a Rust toolchain installed, you can simply:

cargo install dug

The simplest way to install a Rust toolchain is with rustup.

github

Coming soon.

Examples

Example: Table output

$ dug wikipedia.org www.kame.net

┌wikipedia.org─────────────────┬────────────────────┐
│ Quad9 DNS                    │ 198.35.26.96       │
├──────────────────────────────┼────────────────────┤
│ Google DNS                   │ 198.35.26.96       │
├──────────────────────────────┼────────────────────┤
│ Cloudflare DNS               │ 198.35.26.96       │
├──────────────────────────────┼────────────────────┤
│ OS resolution                │ 198.35.26.96       │
├──────────────────────────────┼────────────────────┤
│ simulated nslookup           │ 198.35.26.96       │
├──────────────────────────────┼────────────────────┤
│ resolv.conf server[10.0.0.1] │ 198.35.26.96       │
├──────────────────────────────┼────────────────────┤
│ dig                          │ 198.35.26.96       │
│                              │ 2620:0:863:ed1a::1 │
├──────────────────────────────┼────────────────────┤
│ drill                        │ 198.35.26.96       │
│                              │ 2620:0:863:ed1a::1 │
└──────────────────────────────┴────────────────────┘
┌www.kame.net──────────────────┬────────────────────────────────────┐
│ Google DNS                   │ 210.155.141.200                    │
├──────────────────────────────┼────────────────────────────────────┤
│ Quad9 DNS                    │ 210.155.141.200                    │
├──────────────────────────────┼────────────────────────────────────┤
│ Cloudflare DNS               │ 210.155.141.200                    │
├──────────────────────────────┼────────────────────────────────────┤
│ OS resolution                │ 210.155.141.200                    │
├──────────────────────────────┼────────────────────────────────────┤
│ simulated nslookup           │ 210.155.141.200                    │
├──────────────────────────────┼────────────────────────────────────┤
│ resolv.conf server[10.0.0.1] │ 210.155.141.200                    │
├──────────────────────────────┼────────────────────────────────────┤
│ dig                          │ mango.itojun.org.                  │
│                              │ 210.155.141.200                    │
│                              │ mango.itojun.org.                  │
│                              │ 2001:2f0:0:8800:226:2dff:fe0b:4311 │
│                              │ 2001:2f0:0:8800::1:1               │
├──────────────────────────────┼────────────────────────────────────┤
│ drill                        │ mango.itojun.org.                  │
│                              │ 210.155.141.200                    │
│                              │ mango.itojun.org.                  │
│                              │ 2001:2f0:0:8800::1:1               │
│                              │ 2001:2f0:0:8800:226:2dff:fe0b:4311 │
└──────────────────────────────┴────────────────────────────────────┘

Example: JSON output

$ dug --json wikipedia.org
[
  {
    "name": "aws.amazon.com",
    "source": "Quad9 DNS",
    "records": [
      "18.155.190.47"
    ]
  },
  {
    "name": "aws.amazon.com",
    "source": "Cloudflare DNS",
    "records": [
      "18.155.190.47"
    ]
  },
  {
    "name": "aws.amazon.com",
    "source": "Google DNS",
    "records": [
      "18.155.190.47"
    ]
  },
  {
    "name": "aws.amazon.com",
    "source": "OS resolution",
    "records": [
      "18.155.190.47"
    ]
  },
  {
    "name": "aws.amazon.com",
    "source": "simulated nslookup",
    "records": [
      "18.155.190.47"
    ]
  },
  {
    "name": "aws.amazon.com",
    "source": "resolv.conf server[10.0.0.1]",
    "records": [
      "18.155.190.47"
    ]
  },
  {
    "name": "aws.amazon.com",
    "source": "resolv.conf server[127.0.0.1]",
    "failure": "Timed out after 7s"
  },
  {
    "name": "aws.amazon.com",
    "source": "A (dig)",
    "records": [
      "tp.8e49140c2-frontier.amazon.com.",
      "dr49lng3n1n2s.cloudfront.net.",
      "18.155.190.47"
    ]
  }
]

Example: ASCII text output

$ dug -a wikipedia.org

Name:	wikipedia.org
Source:	Cloudflare DNS
Result:	198.35.26.96

Name:	wikipedia.org
Source:	Quad9 DNS
Result:	198.35.26.96

Name:	wikipedia.org
Source:	Google DNS
Result:	198.35.26.96

Name:	wikipedia.org
Source:	OS resolution
Result:	198.35.26.96

Name:	wikipedia.org
Source:	simulated nslookup
Result:	198.35.26.96

Name:	wikipedia.org
Source:	resolv.conf server[10.0.0.1]
Result:	198.35.26.96

Name:	wikipedia.org
Source:	dig
Result:	198.35.26.96 2620:0:863:ed1a::1

Name:	wikipedia.org
Source:	drill
Result:	198.35.26.96 2620:0:863:ed1a::1

Example: Get only the Google DNS results for a set of hostnames

$ dug -j abc.com cbs.com nbc.com | jq -cr \
    'map(select(.source | contains("Google")))[] | "\(.name)\t\(.records | join(" "))"'
abc.com 65.8.161.63 65.8.161.31 65.8.161.4 65.8.161.47
cbs.com 34.149.41.86
nbc.com 23.67.33.102 23.67.33.74

Example: Extract only the resolved IPs with jq

$ dug -j google.com | jq -r 'map(select(.records).records) | flatten | unique .[]'
142.250.189.174
142.250.191.78
142.251.46.206
172.217.164.110
2607:f8b0:4005:814::200e

This looks busy, but here's what jq is doing:

1. map(...) — for each result in the array...
2. select(.records) — select only objects where the records property is truthy (stripping null)
3. .records — ...and extract the records property from the selected objects
4. flatten the nested of arrays into a single array of all resolved IPs
5. unique — remove all duplicate values
6. .[] — convert the array into a sequence of strings, one per line