Support ALL_PROXY environment variable

[yimsk]

Summary

Support ALL_PROXY environment variable for proxy configuration.

Background

Go's net/http ignores ALL_PROXY - only reads HTTP_PROXY/HTTPS_PROXY.
Users with ALL_PROXY=socks5h://... must manually set HTTPS_PROXY. (Ref: #60)

Proposed Solution

On startup, propagate ALL_PROXY to HTTPS_PROXY only:

if allProxy := getEnv("ALL_PROXY", "all_proxy"); allProxy != "" {
    if getEnv("HTTPS_PROXY", "https_proxy") == "" {
        os.Setenv("HTTPS_PROXY", allProxy)
    }
}

Why HTTPS_PROXY only?

• AWS API calls use HTTPS → HTTPS_PROXY covers all AWS traffic
• HTTP is only used for IMDS (169.254.169.254) which must NOT be proxied
• No need to manipulate NO_PROXY

References

• "Press Enter or Space to continue" but neither works #60 (original report)

[otonoton]

AWS API calls use HTTPS → HTTPS_PROXY covers all AWS traffic

But it is still possible to use a proxy that only speaks non-encrypted HTTP between client<->proxy even if the request is for a TLS-enabled site.

https://developer.mozilla.org/en-US/docs/Web/HTTP/Reference/Methods/CONNECT

Many proxy providers (even paid ones) still offer (and sometimes only offer) access to https sites via an "http-only" proxy that blindly forwards the TLS data via CONNECT, and this kind of proxy only makes sense as an HTTP_PROXY, whereas an HTTPS_PROXY would first establish a TLS connection to the proxy itself before making a request of either type (http or https).

[yimsk]

Good point, agreed. Adding HTTP_PROXY propagation and auto NO_PROXY configuration.

• ALL_PROXY → both HTTP_PROXY + HTTPS_PROXY
• NO_PROXY auto-adds IMDS/ECS/EKS endpoints

b6a27a5

[yimsk]

Decision: Do not touch NO_PROXY

Only implement ALL_PROXY → HTTP_PROXY/HTTPS_PROXY propagation.

NO_PROXY auto-configuration (e.g., IMDS exclusion) will NOT be done. User responsibility.

Reasons:

• Minimize side effects of modifying environment
• NO_PROXY is often policy-managed in enterprise environments
• Keep design simple: claws only interprets ALL_PROXY

[yimsk]

Implemented in PR #74

[otonoton]

Thank you!