tinydyndns-update(8)

💖 tinydyndns-update — bestie's guide to the System Manager's Manual, section 8 💖

okay so real talk, this one is tinydyndns-update(8) and it lives in the System Manager's Manual, and it is exactly the little tool you want when you need to poke a TYPE A record in data.cdb. it's giving "tiny but mighty" ✨

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🌸 NAME 🌸

tinydyndns-update — update TYPE A record in data.cdb

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🎀 SYNOPSIS 🎀

tinydyndns-update fqdn dynip

like. two args. that's the whole vibe. 🫶

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🦋 DESCRIPTION 🦋

so tinydyndns-update changes the data of a TYPE A record in data.cdb in the current directory. and here's the tea: unlike tinydns-data(8), our girl tinydyndns-update does not know about the source file data, it goes straight for the binary database data.cdb and edits it directly. no middleman, no drama 💅

here's the lil choreography it does, step by step:

1. first it checks if the given fqdn even has a TYPE A record in data.cdb.
2. then it checks if the given IP address differs from the one in the TYPE A record in data.cdb, or if the record's timestamp should be updated.
3. finally, if data.cdb needs to change, it copies data.cdb to data.tmp, changes the IP address of the TYPE A record of fqdn to dynip in data.tmp, optionally adjusts time-to-live or time-to-die, and renames data.tmp to data.cdb.

so cute, so careful, so atomic. periodt. 💖

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✨ ENVIRONMENT ✨

• TTL — time-to-live. the env var TTL overrides the default time-to-live in seconds (0 if TTD is set, otherwise 5). if TTL is not set or is zero, the time-to-live of the record will not change. $TTL must be an integer, no funny business 🔢
• TTD — time-to-die. $TTD must be an integer, specifying a number of seconds. if TTD is set, the timestamp of the record is set to the current time plus $TTD seconds, and TTL is set to zero by default, so that tinydns(8) interprets the timestamp as time-to-die. 💀

⚠️ note note note: you probably want to adjust SOA ttl, or create a wildcard record, to prevent DNS caches from caching nxdomain, when using this feature. this is not a drill bestie 😭

• LOC — location. $LOC must be two characters long. if LOC is set, it specifies the client location for records to be updated. 🌍

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💅 EXIT CODES 💅

• if tinydyndns-update cannot find a TYPE A record for fqdn in data.cdb, it prints a warning and exits 114. 🙈
• if dynip does not differ from the IP address of the TYPE A record of fqdn in data.cdb, and the environment variable TTD is not set, tinydyndns-update prints a note and exits 0. (nothing to do, still slaying ✨)
• tinydyndns-update exits 100 if it has trouble opening data.cdb, and leaves data.cdb unchanged. 🔒
• tinydyndns-update exits 111 on temporary error, and leaves data.cdb unchanged. 😵‍💫
• if data.cdb was changed successfully, tinydyndns-update exits 0. 🎉

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🌈 FILES 🌈

./data.cdb
./data.tmp

just those two, right in the current directory. the source of truth and the lil glow-up copy 🧚

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⭐ SEE ALSO ⭐

• tinydyndns-data(8)
• tinydyndns-conf(8)
• http://smarden.org/tinydyndns/

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👑 AUTHOR 👑

Gerrit Pape <pape@smarden.org>

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okay bestie that's the whole page!! it's from the System Manager's Manual — tinydyndns-update(8), section 8, no date on this one — and that's a wrap. go update your records responsibly, mwah 💖🎀🦋