Add support for explicit http-proxying

[nicolasduczek]

What would you like to be added:

Support should be added to enable (non-transparent) http-proxy as typically configured via HTTP_PROXY / HTTPS_PROXY environment variables in the form of

$https_proxy=http://user:password@ProxyIP:80
$http_proxy=http://user:password@ProxyIP:80

Why is this needed:

In order to access resources through a http-proxy

[morri-son]

Hi @nicolasduczek, we tried to reproduce your issue with the following setup, but didn't run into issues. We used the standard OS env variables to configure an HTTP proxy. We set up a local OCI registry listening on port 5000 and a local http proxy listening on port 8080.

We used another alias for localhost in /etc/hosts, because go has a special handling for localhost with regards to proxies, then we did (with ls-registry being the alias for the OCI registry):

HTTP_PROXY=localhost:8080 HTTPS_PROXY=localhost:8080 ocm get component http://ls-registry:5000/ocm//ocm.software/ocmcli

and got a correct answer from the OCM CLI:

2024-11-07T12:59:36+01:00 warning [ocm/oci/ocireg] "using insecure http for oci registry ls-registry:5000"
COMPONENT           VERSION PROVIDER
ocm.software/ocmcli 0.7.0   ocm.software

Can you please ask the client to check if the same is possible at their side? If there run into any issues, please attach as much information about environment, usage and errors to this issue so that we can look into the problem again.

[hilmarf]

The folks say that an `ocm transfer cv my-registry/my-repo/my-component:0.8.15 /mnt/my-filesystem does not work in a Proxy env

[jakobmoellerdev]

We did verify that most / if not all HTTP clients we create use HTTP_PROXY / HTTPS_PROXY and that transfers worked as well. we would need a concrete reproducer first. This issue is otherwise unacceptable