oras repo ls takes ~30 seconds to list ~5 elements of the namespace (registry is just 140 size)

[borjamunozf]

Hello everyone.

We have a TUI that uses internally the _oras repo ls myregistry/whatevernamespace to list artifacts under a namespace and renders the results in it. This is done before the TUI is rendered.

However, we realized that the startup is incredible slow. Debugging the application we see that the time is spent doing the request call in the Registry>Repositories

The call to the API /v2/catalog_ just gets 100 elements first of the registry, then get the next page & there is it.
Using --last seems to provide certain improvement at first call, but still annoyingly slow.

So:

• Is there any alternative to this? Any way to get this data as quick as possible? Any other API call? Any hack?

Thanks

[Wwwsylvia]

Hi @borjamunozf , are you using the ORAS CLI or the oras-go library? Would you mind sharing the debug logs for repo ls myregistry/whatevernamespace --debug? You may remove any sensitive information in the logs before sharing.

[borjamunozf]

I tested both, but it's clearly a problem with the API response time, that's why I see that it's not a fault with ORAS call itself.
I don't know if there's other alternative to achieve this is in a more performant way?

plain ORAS CLI

time oras repo ls whateverdockerregistry.azurecr.io/whatever --debug

DEBU[0000] Request #0
> Request URL: "https://whateverdockerregistry.azurecr.io/whatever/v2/_catalog"
> Request method: "GET"
> Request headers:
   "User-Agent": "oras/1.2.2"
DEBU[0000] Response #0
< Response Status: "401 Unauthorized"
< Response headers:
   "Content-Length": "196"
   "Www-Authenticate": "Bearer realm=\"https://whateverdockerregistry.azurecr.io/oauth2/token\",service=\"whateverdockerregistry.azurecr.io\",scope=\"registry:catalog:*\""
   "Content-Type": "application/json; charset=utf-8"
   "Connection": "keep-alive"
   "Server": "AzureContainerRegistry"
   "Access-Control-Expose-Headers": "Docker-Content-Digest, WWW-Authenticate, Link, X-Ms-Correlation-Request-Id"
   "X-Content-Type-Options": "nosniff"
   "X-Ms-Correlation-Request-Id": "44e0f109-531d-4231-83df-738fe60b548e"
   "Date": "Wed, 12 Mar 2025 21:35:27 GMT"
   "Docker-Distribution-Api-Version": "registry/2.0"
   "Strict-Transport-Security": "max-age=31536000; includeSubDomains, max-age=31536000; includeSubDomains"
DEBU[0000] Request #1
> Request URL: "https://whateverdockerregistry.azurecr.io/oauth2/token"
> Request method: "POST"
> Request headers:
   "Content-Type": "application/x-www-form-urlencoded"
   "User-Agent": "oras/1.2.2"
DEBU[0000] Response #1
< Response Status: "200 OK"
< Response headers:
   "Date": "Wed, 12 Mar 2025 21:35:28 GMT"
   "Content-Type": "application/json; charset=utf-8"
   "Connection": "keep-alive"
   "X-Ms-Correlation-Request-Id": "4ec29a02-aa1a-4507-a7cd-3853d801f947"
   "X-Ms-Ratelimit-Remaining-Calls-Per-Second": "333.316667"
   "Strict-Transport-Security": "max-age=31536000; includeSubDomains"
   "Server": "AzureContainerRegistry"
DEBU[0000] Request #2
> Request URL: "https://whateverdockerregistry.azurecr.io/v2/_catalog"
> Request method: "GET"
> Request headers:
   "Authorization": "*****"
   "User-Agent": "oras/1.2.2"
DEBU[0015] Response #2
< Response Status: "200 OK"
< Response headers:
   "Content-Type": "application/json; charset=utf-8"
   "X-Content-Type-Options": "nosniff"
   "Server": "AzureContainerRegistry"
   "Docker-Distribution-Api-Version": "registry/2.0"
   "X-Ms-Correlation-Request-Id": "a1f6d3f0-9bd7-463b-9ed0-03412c593512"
   "Access-Control-Expose-Headers": "Docker-Content-Digest, WWW-Authenticate, Link, X-Ms-Correlation-Request-Id"
   "Link": "</v2/_catalog?last=whatever-asd-asdasd&n=100&orderby=>; rel=\"next\""
   "Strict-Transport-Security": "max-age=31536000; includeSubDomains, max-age=31536000; includeSubDomains"
   "Date": "Wed, 12 Mar 2025 21:35:43 GMT"
   "Connection": "keep-alive"
DEBU[0015] Request #3
> Request URL: "https://whateverdockerregistry.azurecr.io/v2/_catalog?last=asdf-whatever-sim&n=100&orderby="
> Request method: "GET"
> Request headers:
   "Authorization": "*****"
   "User-Agent": "oras/1.2.2"
DEBU[0035] Response #3
< Response Status: "200 OK"
< Response headers:
   "Date": "Wed, 12 Mar 2025 21:36:03 GMT"
   "Connection": "keep-alive"
   "Link": "</v2/_catalog?last=roc%2Fsimulators%2Fasdf-asdf-bootstrap&n=100&orderby=>; rel=\"next\""
   "X-Ms-Correlation-Request-Id": "ee0ed6e2-5b4d-4810-a21a-9628573d7bfe"
   "Docker-Distribution-Api-Version": "registry/2.0"
   "X-Content-Type-Options": "nosniff"
   "Access-Control-Expose-Headers": "Docker-Content-Digest, WWW-Authenticate, Link, X-Ms-Correlation-Request-Id"
   "Server": "AzureContainerRegistry"
   "Content-Type": "application/json; charset=utf-8"
   "Strict-Transport-Security": "max-age=31536000; includeSubDomains, max-age=31536000; includeSubDomains"
my-result-finally
my-result-finally-2
my-result-finally-3
my-result-finally-4
my-result-finally-5
DEBU[0035] Request #4
> Request URL: "https://whateverdockerregistry.azurecr.io/v2/_catalog?last=whatever%asdfasdasd%2Fasdasdasdasdas&n=100&orderby="
> Request method: "GET"
> Request headers:
   "Authorization": "*****"
   "User-Agent": "oras/1.2.2"
DEBU[0043] Response #4
< Response Status: "200 OK"
< Response headers:
   "Docker-Distribution-Api-Version": "registry/2.0"
   "Link": "</v2/_catalog?last=quefacemos_noxovidar&n=100&orderby=>; rel=\"next\""
   "Strict-Transport-Security": "max-age=31536000; includeSubDomains, max-age=31536000; includeSubDomains"
   "Access-Control-Expose-Headers": "Docker-Content-Digest, WWW-Authenticate, Link, X-Ms-Correlation-Request-Id"
   "Connection": "keep-alive"
   "X-Content-Type-Options": "nosniff"
   "Server": "AzureContainerRegistry"
   "Content-Type": "application/json; charset=utf-8"
   "X-Ms-Correlation-Request-Id": "4a4bae0c-62b5-46e8-b568-dbb701b8843b"
   "Date": "Wed, 12 Mar 2025 21:36:11 GMT"
DEBU[0043] Request #5
> Request URL: "https://whateverdockerregistry.azurecr.io/v2/_catalog?last=quefacemos_noxovidar&n=100&orderby="
> Request method: "GET"
> Request headers:
   "Authorization": "*****"
   "User-Agent": "oras/1.2.2"
DEBU[0043] Response #5
< Response Status: "200 OK"
< Response headers:
   "Date": "Wed, 12 Mar 2025 21:36:11 GMT"
   "Content-Type": "application/json; charset=utf-8"
   "X-Content-Type-Options": "nosniff"
   "Server": "AzureContainerRegistry"
   "Content-Length": "119"
   "Docker-Distribution-Api-Version": "registry/2.0"
   "Strict-Transport-Security": "max-age=31536000; includeSubDomains, max-age=31536000; includeSubDomains"
   "X-Ms-Correlation-Request-Id": "8e6d79d9-6e6b-46e0-88ce-6ae83967f9c4"
   "Connection": "keep-alive"
   "Access-Control-Expose-Headers": "Docker-Content-Digest, WWW-Authenticate, Link, X-Ms-Correlation-Request-Id"

real 0m43.487s
user 0m0.025s
sys 0m0.069s

[Wwwsylvia]

/v2/_catalog is the only standard API to list the repositories. Some registries might provide their own vendor-specific API, but one won't be able to invoke such API via ORAS🫤