feat: add dnslink support and update t0109

[laurentsenta]

Contributes to #26
Closes #22

This tests adds dnslink support:

We introduce a fixture type which contains a dnslink configuration:

dnslinks:
  custom-dnslink:
    subdomain: dnslink-enabled-on-fqdn
    path: /ipfs/QmYBhLYDwVFvxos9h8CGU2ibaY66QNgv8hpfewxaQrPiZj

Test writer uses the fixture with:

dnsLinks := dnslink.MustOpenDNSLink("t0109-dnslink.yml")
dnsLink := dnsLinks.Get("custom-dnslink")

// then use it in your subdomain gateway URL test:
gatewayURL := SubdomainGatewayURL
u, _ := url.Parse(gatewayURL)

// dnsLinkBaseUrl = "http://dnslink-enabled-on-fqdn.foo.bar.example.com"
dnsLinkBaseUrl := fmt.Sprintf("%s://%s%s", u.Scheme, dnsLink, u.Host)

Test user calls the export CLI to get the yml files. We also generate a dnslinks.json.

There is a demo in kubo-config.example.sh that shows how to import the fixtures:

IPFS_NS_MAP=$(cat ./dnslinks.json | jq -r 'to_entries | map("\(.key).example.com:\(.value)") | join(",")')

echo "Set the following IPFS_NS_MAP before starting the kubo daemon:"
echo "IPFS_NS_MAP=${IPFS_NS_MAP}"

Todo

• Clarify the API and how we want to expose this to users
• helper libs reusable
• finalize in CI (import the env when the daemon starts)

[laurentsenta]

failing test on purpose: https://github.com/ipfs/gateway-conformance/actions/runs/4924297430

[galargh]

Nothing blocking 🥇

[lidel]

(github was down and missed oportunity to review earlier)

@laurentsenta i am bit confused – whgy is this "subdomain" specific?

DNSLink TXT records can be present on subdomains OR the top domains right after TLD.
Should this be renamed to fqdn or plain domain?

[laurentsenta]

(github was down and missed oportunity to review earlier)

👍 thanks for reviewing anyway; happy to fix if the approach is lacking, @hacdias had a similar question when we reviewed it.

DNSLink TXT records can be present on subdomains OR the top domains right after TLD.

We want to configure the top domain + tld during test EXECUTION, not at test definition: two users might run that test on different subdomain gateway URLs, example.com and dweb.link for example.

This means we want to be able to construct URLs with {dns-link.subdomain}.{gateway_url} at run time (actual code).

Thinking about it, I guess we might want to define a fqdn/domain, like

dnslinks:
    wikipedia:
        domain: wikipedia-on-ipfs.org
        path: /ipfs/somethingsomething

but that would be a different test, we do need to keep the subdomain option to port most of the tests like 114 and 109.

That's my understanding so far, let me know if I'm missing something!