Feature: add IFSC service

[gopuvenkat]

Add IFSC service - Closes #81

IFSC data is read from disk and loaded into memory to respond to requests. The download link mentioned in config.sample.toml fetches the latest dump of IFSC data.

1. make build output

❯ make build
CGO_ENABLED=0 go build -o dnstoys.bin -ldflags="-s -w -X 'main.buildString=v1.1.0-11-g22d3 (build "\#"22d3e73 2024-12-31 14:31:22)'" ./cmd/dnstoys/*.go

2. Running DNS server

❯ ./dnstoys.bin
2024/12/31 14:32:19 main.go:72: reading config: config.toml
2024/12/31 14:32:19 main.go:162: reading geo locations from data/cities15000.txt
2024/12/31 14:32:21 main.go:170: 29275 geo location names loaded
2024/12/31 14:32:21 loading wordnet data from data/wordnet
2024/12/31 14:32:21 loaded wordnet dictionary data
2024/12/31 14:32:21 loading IFSC data from data/ifsc
2024/12/31 14:32:22 loaded IFSC data
2024/12/31 14:32:22 main.go:381: listening on  :5354

3. Running queries from another terminal

❯ dig ABNA0000001.ifsc @127.0.0.1 -p 5354

; <<>> DiG 9.10.6 <<>> ABNA0000001.ifsc @127.0.0.1 -p 5354
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 39574
;; flags: qr rd; QUERY: 1, ANSWER: 4, AUTHORITY: 0, ADDITIONAL: 0
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;ABNA0000001.ifsc.		IN	A

;; ANSWER SECTION:
ABNA0000001.ifsc.	1	IN	TXT	"BANK: Royal Bank of Scotland N.V."
ABNA0000001.ifsc.	1	IN	TXT	"BRANCH: RTGS-HO"
ABNA0000001.ifsc.	1	IN	TXT	"CITY: GREATER BOMBAY"
ABNA0000001.ifsc.	1	IN	TXT	"STATE: MAHARASHTRA"

;; Query time: 2 msec
;; SERVER: 127.0.0.1#5354(127.0.0.1)
;; WHEN: Tue Dec 31 14:40:30 IST 2024
;; MSG SIZE  rcvd: 236

❯ dig ANZB0000001.ifsc +short @127.0.0.1 -p 5354
"BANK: Australia and New Zealand Banking Group"
"BRANCH: RTGS-HO"
"CITY: MUMBAI"
"STATE: MAHARASHTRA"

❯ dig incorrectIFSC.ifsc @127.0.0.1 -p 5354

; <<>> DiG 9.10.6 <<>> incorrectIFSC.ifsc @127.0.0.1 -p 5354
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 62955
;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; WARNING: recursion requested but not available

;; QUESTION SECTION:
;incorrectIFSC.ifsc.		IN	A

;; ADDITIONAL SECTION:
.			1	IN	TXT	"error: invalid IFSC code length: 13"

;; Query time: 1 msec
;; SERVER: 127.0.0.1#5354(127.0.0.1)
;; WHEN: Tue Dec 31 14:36:25 IST 2024
;; MSG SIZE  rcvd: 83

[SaiSkandaTNI]

The below might be a useful addition to quick start this, a single commad to download and untar. Same canbe used in a cronjob to keep it upto date. Also might be useful to retain the by-bank/ folder incase another method / file from razorpay also needs to be included. The below unatars into ifsc/by-bank/

cd [your_dns_toys_data_directory] && mkdir -p ifsc && cd ifsc && mkdir -p by-bank && rm -r by-bank && curl -L -s $(curl -s https://api.github.com/repos/razorpay/ifsc/releases/latest | grep "browser_download_url" | grep "by-bank.tar.gz" | sed -E 's/.*"([^"]+)".*/\1/') -o by-bank.tar.gz && tar -xzf by-bank.tar.gz && rm by-bank.tar.gz

[SaiSkandaTNI]

might also want to add data/ifsc to gitignore

[SaiSkandaTNI]

Is it possible to send everything that is available instead of restricting to these 5?