dns.client

new(cfg) -> resolver, err

Create a new DNS resolver

Configuration fields:

• servers — list of upstream DNS servers (required); entries can be IP strings ("1.1.1.1") or tables ({ host = "1.1.1.1", port = 5353 }); port is optional and defaults to 53 (or 853 for TLS)
• timeout — socket timeout in seconds (default 5)
• retries — retry attempts per query (default 2)
• use_tcp — force TCP for all queries (default false)
• use_tls — use DNS-over-TLS on port 853 (default false)
• ndots — search list dot threshold (default 1)
• search — search domain list (default {})
• edns_buffer_size — EDNS advertised UDP payload size (default 4096)
• use_0x20 — enable 0x20 query name encoding (default false)
• cache — dns.cache instance for caching (default nil, no caching)
• server_name — TLS SNI hostname (TLS only)
• cafile — path to CA certificate bundle (TLS only)
• capath — path to CA certificate directory (TLS only)
• verify — enable TLS certificate verification (default true)

local dns_client = require("dns.client")
local dns_cache = require("dns.cache")

-- Simple resolver
local r = dns_client.new({ servers = { "1.1.1.1", "8.8.8.8" } })
local answers, err = r:resolve("example.com", "A")

-- Per-server port
local r = dns_client.new({
    servers = { { host = "127.0.0.1", port = 5353 }, "8.8.8.8" },
})

-- From system resolv.conf
local sys = dns_client.parse_resolv_conf()
local r = dns_client.new(sys)

-- DNS-over-TLS
local r = dns_client.new({
    servers = { "1.1.1.1" },
    use_tls = true,
})