Some more documentation in the blog post

Signed-off-by: Jacob Kiers <jacob@jacobkiers.net>
This commit is contained in:
Jacob Kiers 2021-08-17 09:32:33 +02:00
parent 2a5b04d8d5
commit c094816d76
2 changed files with 59 additions and 4 deletions

7
Corefile Normal file
View File

@ -0,0 +1,7 @@
hod.experiments.jacobkiers.net.:53 {
log
auto hod.experiments.jacobkiers.net. {
directory /etc/coredns/zones/
reload 10s
}
}

View File

@ -1,12 +1,16 @@
+++ +++
title = Serving blog content over DNS title = HTML over DNS: Serving Blog Content Over DNS
date = 2021-08-15 date = 2021-08-15
author = Jacob Kiers author = Jacob Kiers
+++ +++
## What's up?
You might not be able to see it immediately, but the content of this page is verved over DNS. You might not be able to see it immediately, but the content of this page is verved over DNS.
This works because of the new DNS-over-HTTP support, which, at least at Cloudflare, also has an API. This works because of [DNS over HTTPS] for which there is an [API from Cloudflare].
## How it works
That API is used to load the contents of this page, essentially like this: That API is used to load the contents of this page, essentially like this:
@ -14,6 +18,50 @@ That API is used to load the contents of this page, essentially like this:
fetch("https://cloudflare-dns.com/dns-query?ct=application/dns-json&type=TXT&name=post.hod.experiments.jacobkiers.net"); fetch("https://cloudflare-dns.com/dns-query?ct=application/dns-json&type=TXT&name=post.hod.experiments.jacobkiers.net");
``` ```
Please see the [source code] for the details of how it works. The content itself is served over DNS, using CoreDNS, with these contents:
[source code]: https://github.com/jacobkiers/html-over-dns ```js
hod.experiments.jacobkiers.net.:53 {
log
auto hod.experiments.jacobkiers.net. {
directory /etc/coredns/zones/
reload 10s
}
}
```
This feeds into a zone file, which looks like this:
```js
$TTL 5m ; Default TTL
@ IN SOA experiments.jacobkiers.net. postmaster.jacobkiers.net. (
2021081612 ; serial
1h ; slave refresh interval
15m ; slave retry interval
1w ; slave copy expire time
1h ; NXDOMAIN cache time
)
$ORIGIN hod.experiments.jacobkiers.net.
;
; domain name servers
;
@ IN NS experiments.jacobkiers.net.
;; START BLOG RECORDS
; posts-2021-08-17-serving-blog-content-over-dns-md
posts-2021-08-17-serving-blog-content-over-dns-md 60 IN TXT "t=text/markdown;c=3;h=2fd63f0f408ad1336283999d0487ced9;m=eyJ0aXRsZSI6IlNlcnZpbmcgYmxvZyBjb250ZW50IG92ZXIgRE5TIiwiZGF0ZSI6IjIwMjEtMDgtMTUiLCJhdXRob3IiOiJKYWNvYiBLaWVycyJ9"
0.2fd63f0f408ad1336283999d0487ced9 60 IN TXT "WW91IG1pZ2h0IG5vdCBiZSBhYmxlIHRvIHNlZSBpdCBpbW1lZGlhdGVseSwgYnV0IHRoZSBjb250ZW50IG9mIHRoaXMgcGFnZSBpcyB2ZXJ2ZWQgb3ZlciBETlMuCgpUaGlzIHdvcmtzIGJlY2F1c2Ugb2YgdGhlIG5ldyBETlMtb3Zlci1IVFRQIHN1cHBvcnQsIHdoaWNoLCBhdCBsZWFzdCBhdCBDbG91ZGZsYXJlLCBhbHNvIGhhcy"
1.2fd63f0f408ad1336283999d0487ced9 60 IN TXT "BhbiBBUEkuCgpUaGF0IEFQSSBpcyB1c2VkIHRvIGxvYWQgdGhlIGNvbnRlbnRzIG9mIHRoaXMgcGFnZSwgZXNzZW50aWFsbHkgbGlrZSB0aGlzOgoKYGBganMKZmV0Y2goImh0dHBzOi8vY2xvdWRmbGFyZS1kbnMuY29tL2Rucy1xdWVyeT9jdD1hcHBsaWNhdGlvbi9kbnMtanNvbiZ0eXBlPVRYVCZuYW1lPXBvc3QuaG9kLmV4cGVy"
2.2fd63f0f408ad1336283999d0487ced9 60 IN TXT "aW1lbnRzLmphY29ia2llcnMubmV0Iik7CmBgYAoKUGxlYXNlIHNlZSB0aGUgW3NvdXJjZSBjb2RlXSBmb3IgdGhlIGRldGFpbHMgb2YgaG93IGl0IHdvcmtzLgoKW3NvdXJjZSBjb2RlXTogaHR0cHM6Ly9naXRodWIuY29tL2phY29ia2llcnMvaHRtbC1vdmVyLWRucwo="
```
These records are base64 encoded content, so when concatenated and decoded, they give the content of the posts.
Please see the [source code] for the details.
[source code]: https://github.com/jacobkiers/html-over-dns "Yes, the title is a pun..."
[DNS over HTTPS]: https://en.wikipedia.org/wiki/DNS_over_HTTPS
[API from Cloudflare]: https://developers.cloudflare.com/1.1.1.1/dns-over-https/json-format