feat: Add proxy support to CLI API client

[shimako55]

Fixes #10794

Motivation

Issue:
In the current version of Argo Workflows, the API client does not function properly in environments that use a proxy server.

Purpose:
This PR aims to modify the Argo Workflows API client to ensure it functions correctly when routing through a proxy server.

Modifications

Summary of Changes:
Made modifications in cmd/argo/commands/client/conn.go, pkg/apiclient/apiclient.go, pkg/apiclient/http1-client.go, and pkg/apiclient/http1/facade.go.

Specific Changes:
Added proxy functionality using http.ProxyURL.
Integrated new proxy settings into the API client construction process.
Added proxy settings to the configuration of http.Client and http.Transport.

Reason for Changes:
To support the operation of the API client in proxy environments.

Verification

Testing Method:
Conducted manual tests in an environment with a configured proxy server.

Test Results:
Confirmed that the API client operates correctly when routing through a proxy.

Reproduction Steps:
Replace http://example.com:8080 with your actual proxy server URL in the following commands:

$ ./argo template list --proxy-url=http://example.com:8080

NAME
awesome-tiger

or

$ export HTTPS_PROXY=http://example.com:8080
$ ./argo template list

NAME
awesome-tiger

[isubasinghe]

Can you add some tests in apiclient_test.go and facade_test.go? Thanks

[shimako55]

Okay, thanks. I'll give it a try. However, it might take me some time.

[shimako55]

@isubasinghe
I have added facade_test.go.
I didn't know what tests were expected for apiclient_test.go. Could you please tell me specifically what kind of tests are expected?

[Joibel]

As suggested by @monaka in #12827 (comment), closing as implemented by #12867.

[Joibel]

Oops, this isn't implemented there.

[shimako55]

Requesting a review for this PR.
I’d appreciate any feedback, particularly on the http.Client integration. Thanks in advance!

[shimako55]

Hello @isubasinghe
Could you please review this PR again when you have a moment?

[isubasinghe]

I wasn't able to get this to work, I ran a proxy server (https://github.com/neevek/omnip) on 8899.

I got: "./argo template list --proxy-url=http://localhost:8899"

I then tried to manually set the argo-server URL to localhost:2746.

When I did this, I did get this in my cli:
FATA[2024-11-29T14:07:09.786Z] could not find a token

Can you take another look at this please?

[shimako55]

Thanks @isubasinghe
I was able to successfully execute the following steps in my environment.

1. Test Environment

Installed Argo Workflows in local environment using kind

2. Server Connection Setup

Set up port forwarding to connect to the Argo server in the Kubernetes cluster:

kubectl -n argo port-forward service/argo-server 8080:2746

3. Environment Variables Configuration

Set required environment variables for Argo CLI connection:

export ARGO_SERVER='localhost:8080'
export ARGO_HTTP1=true
export ARGO_SECURE=true
export ARGO_BASE_HREF=
export ARGO_TOKEN=''
export ARGO_NAMESPACE=argo

4. Proxy Server Launch

Started proxy server using omnip:

omnip -a http://0.0.0.0:8081 -lD

5. Operation Check Results

Argo CLI Verification

argo list -k --proxy-url=http://localhost:8081

Execution Result

NAME                STATUS      AGE   DURATION   PRIORITY   MESSAGE
hello-world-256m7   Succeeded   1h    25s        0

Proxy Server Logs

2024-12-04 14:55:26.723 [omnip] [omnip::server:717] [D] serve request directly: localhost:8080 from 127.0.0.1:49532
2024-12-04 14:55:26.723 [omnip] [rs_utilities::dns:163] [D] resolved [localhost] to [127.0.0.1]
2024-12-04 14:55:26.723 [omnip] [omnip::server:876] [D] sess start: 127.0.0.1:49532      ↔ 127.0.0.1:8080
2024-12-04 14:55:26.737 [omnip] [omnip::server:942] [D] sess end  : 127.0.0.1:49532      ↔ 127.0.0.1:8080       | ⟳ 8       | ↑ 1931       ↓ 3782