dynamic DNS you say?

• set any ddns to any domain you want. open webpage -> my.ddns.est.im -> filling ip or hostname -> done.
  • implicit CNAME
    • cache and aggregating service
      • cache with TTL
      • combine results instead of Round-Robin
      • dynamic weight
      • premium http/smtp checking
      • blacklist & cache invalidation policy
  • explicit CNAME
• loose API in RESTful manner
• detect recursive DNS API, in case you are behind a DNS forwarder.
• monitor port 53 spams
  • socket reuse routing to other apps
  • every query is logged
• experimental R/W Python Dict Notation Format as "Zone File"
  • functions are also values (lambdas)
  • basically dict() but ordered
  • reference pointers e.g. parent, sibling, etc.
  • deep traversal mergable
  • iterative/partial parsing for streams
  • differential transport in incremental data
• collect ISP DNS from all over the world
  • act as both forwarder and recursive dns
  • history IP database
• DNS over HTTP
  • find the quickest record using TCP PING in ajax

GOPATH=$PWD go get github.com/mattn/go-sqlite3

• How to tell Windows & *nix:
  • Windows will lookup PTR
  • ttl maybe?
• LMDB
  • http://symas.com/mdb/
  • lmdb.readthedocs.org
  • gitorious.org/mdb/mdb
  • http://godoc.org/github.com/szferi/gomdb
• sqlite
  • https://github.com/mattn/go-sqlite3/blob/master/_example/simple/simple.go
• name
  • see 4.1.4. Message compression
  • http://www.ietf.org/rfc/rfc1035.txt

UPSERT in SQLite

Not easy. http://stackoverflow.com/a/7511635/41948

// insert into record (id, name_r, type_id, value) values (1, 'com reddit', 1, X'173E6D57');

INSERT OR REPLACE INTO record (id, name_r, ttl, type_id, value)
SELECT old.id, old.name_r, new.ttl, old.type_id, old.value
FROM ( SELECT
   'com reddit'    AS name_r, 
   1234           AS ttl,
   1  as type_id,
   X'173E6D57' as value
) AS new
LEFT JOIN (
   SELECT id, name_r, type_id, value
   FROM record
) AS old ON new.name_r = old.name_r AND new.type_id = old.type_id AND new.value = old.value;

INSERT OR REPLACE INTO record SELECT old.id, COALESCE(new.name_r, old.name_r), MAX(COALESCE(old.ttl, 0), new.ttl), COALESCE(new.type_id, old.type_id), COALESCE(new.value, old.value), COALESCE(old.time_added, new.time_added), new.time_accessed FROM ( SELECT 'com reddit' AS name_r, 1234 AS ttl, 1 AS type_id, X'173E6D57' AS value, datetime('now') AS time_added, datetime('now') AS time_accessed ) AS new LEFT JOIN ( SELECT id, name_r, ttl, type_id, value, time_added FROM record ) AS old ON new.name_r = old.name_r AND new.type_id = old.type_id AND new.value = old.value;

    old.id, 
    COALESCE(new.name_r, old.name_r), 
    MAX(COALESCE(old.ttl, 0), new.ttl), 
    COALESCE(new.type_id, old.type_id), 
    COALESCE(new.value, old.value), 
    COALESCE(old.time_added, new.time_added), 

package main

import "fmt"

func main() { cb := make(chan int, 1) tidMap := map[int] chan int{ 1234: cb, }

tidMap[1234] <- 333 fmt.Println(<-tidMap[1234]) tidMap[1234] <- 111 tidMap[1234] <- 112 // blocks fmt.Println(<-tidMap[1234]) fmt.Println(<-tidMap[1231]) // blocks

cb := make(chan int, 1) cb <- 1111 tidMap := map[int] chan int{} tidMap[1234] = cb fmt.Println(<-tidMap[1234]) tidMap[1234] <- 111 fmt.Println(<-tidMap[1234])

}

CNAME cache

0000 00 03 81 80 00 01 00 07 00 00 00 00 0a 75 75 75 .............uuu 0010 75 31 32 33 38 37 35 09 77 6f 72 64 70 72 65 73 u123875.wordpres 0020 73 03 63 6f 6d 00 00 01 00 01 c0 0c 00 05 00 01 s.com........... 0030 00 00 38 40 00 05 02 6c 62 c0 17 c0 36 00 01 00 ..8@...lb...6... 0040 01 00 00 01 2c 00 04 4c 4a fe 7b c0 36 00 01 00 ....,..LJ.{.6... 0050 01 00 00 01 2c 00 04 4c 4a fe 78 c0 36 00 01 00 ....,..LJ.x.6... 0060 01 00 00 01 2c 00 04 42 9b 09 ee c0 36 00 01 00 ....,..B....6... 0070 01 00 00 01 2c 00 04 c0 00 50 fa c0 36 00 01 00 ....,....P..6... 0080 01 00 00 01 2c 00 04 42 9b 0b ee c0 36 00 01 00 ....,..B....6... 0090 01 00 00 01 2c 00 04 c0 00 51 fa ....,....Q.