kumo.dns: add lookup_txt

crates/mod-dns-resolver/src/lib.rs

@@ -1,7 +1,7 @@
 use anyhow::Context;
 use config::{any_err, get_or_create_sub_module, serialize_options};
 use dns_resolver::resolver::Resolver;
-use dns_resolver::{resolve_a_or_aaaa, MailExchanger};
+use dns_resolver::{get_resolver, resolve_a_or_aaaa, MailExchanger};
 use hickory_resolver::config::{NameServerConfig, Protocol, ResolverConfig, ResolverOpts};
 use hickory_resolver::{Name, TokioAsyncResolver};
 use mlua::{Lua, LuaSerdeExt};
@@ -18,6 +18,15 @@ pub fn register(lua: &Lua) -> anyhow::Result<()> {
         })?,
     )?;
 
+    dns_mod.set(
+        "lookup_txt",
+        lua.create_async_function(|_lua, domain: String| async move {
+            let resolver = get_resolver();
+            let answer = resolver.resolve_txt(domain).await.map_err(any_err)?;
+            Ok(answer.as_txt())
+        })?,
+    )?;
+
     dns_mod.set(
         "lookup_addr",
         lua.create_async_function(|_lua, domain: String| async move {

docs/reference/kumo.dns/lookup_txt.md

@@ -0,0 +1,16 @@
+# `kumo.dns.lookup_txt(DOMAIN)`
+
+{{since('dev')}}
+
+Resolve a TXT record for the requested `DOMAIN`.
+
+Raises an error if the domain doesn't exist.
+
+Returns a lua array-style table with the list of txt records returned from DNS.
+
+```lua
+assert(
+  kumo.serde.json_encode(kumo.dns.lookup_txt 'gmail.com')
+    == '["v=spf1 redirect=_spf.google.com","globalsign-smime-dv=CDYX+XFHUw2wml6/Gb8+59BsH31KzUr6c1l2BPvqKX8="]'
+)
+```