feat: coin toss

[yashvardhan-kukreja]

Signed-off-by: Yashvardhan Kukreja yash.kukreja.98@gmail.com

closes #37

• make build output

  ❯ make build
  CGO_ENABLED=0 go build -o dnstoys.bin -ldflags="-s -w -X 'main.buildString=v1.0.0-4-ge6f3 (build "\#"e6f346b 2022-09-20 01:09:17)'" ./cmd/dnstoys/*.go

• Running the DNS server

  ❯ ./dnstoys.bin
  2022/09/20 01:10:06 main.go:64: reading config: config.toml
  2022/09/20 01:10:06 main.go:154: reading geo locations from cities15000.txt
  2022/09/20 01:10:06 main.go:162: 26237 geo location names loaded
  2022/09/20 01:10:06 main.go:321: listening on  :5354

• Running the queries in a separate terminal

  
  ❯ dig coin @127.0.0.1 -p 5354   

; <<>> DiG 9.10.6 <<>> coin @127.0.0.1 -p 5354 ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 28120 ;; flags: qr rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0 ;; WARNING: recursion requested but not available

;; QUESTION SECTION: ;coin. IN A

;; ANSWER SECTION: coin. 1 IN TXT "tossed = [heads]"

;; Query time: 0 msec ;; SERVER: 127.0.0.1#5354(127.0.0.1) ;; WHEN: Tue Sep 20 01:10:37 IST 2022 ;; MSG SIZE rcvd: 55

```sh
❯ dig 2.coin @127.0.0.1 -p 5354

; <<>> DiG 9.10.6 <<>> 2.coin @127.0.0.1 -p 5354
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 44331
;; flags: qr rd; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;2.coin.                                IN      A

;; ANSWER SECTION:
2.                      1       IN      TXT     "tossed = [tails, tails]"

;; Query time: 0 msec
;; SERVER: 127.0.0.1#5354(127.0.0.1)
;; WHEN: Tue Sep 20 01:10:54 IST 2022
;; MSG SIZE  rcvd: 61

❯ dig 69.coin @127.0.0.1 -p 5354

; <<>> DiG 9.10.6 <<>> 69.coin @127.0.0.1 -p 5354
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 52852
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;69.coin.                       IN      A

;; ADDITIONAL SECTION:
.                       1       IN      TXT     "error: toss overflow"

;; Query time: 0 msec
;; SERVER: 127.0.0.1#5354(127.0.0.1)
;; WHEN: Tue Sep 20 01:11:19 IST 2022
;; MSG SIZE  rcvd: 57

[knadh]

Thanks for the PR @yashvardhan-kukreja. Made a few minor cosmetic changes and merged.