x/pkgsite/cmd/pkgsite: Use relative links for static, etc.

[spkane]

What is the URL of the page with the issue?

N/A

What is your user agent?

Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/123.0.0.0 Safari/537.36

Screenshot

What did you do?

When running pkgsite -open . locally in a remote Visual Studio Code terminal (via code-server), a proxy will be started.

https://coder.com/docs/code-server/latest/guide#stripping-proxyport-from-the-request-path

This typically means that the main page will be at https://${hostname}/proxy/8080/ and the static directories will be under the path /proxy/8080/static/. However, it appears that the site always tries to find them under /static, and there is no obvious way to change this.

What did you see happen?

None of the static CSS or images will load.

What did you expect to see?

All of the static CSS and images load.

[seankhliao]

where is this visual studio code feature documented?

[spkane]

where is this visual studio code feature documented?

@seankhliao I updated the title and description a bit. It looks like this specific issue is directly related to using code-server. A similar problem might also occur with codespaces or openvscode-server, but I am not sure about that.

It looks like this feature is where the issue is manifesting itself.

https://coder.com/docs/code-server/latest/guide#stripping-proxyport-from-the-request-path

---

Stripping /proxy/<port> from the request path

You may notice that the code-server proxy strips /proxy/<port> from the request path.

HTTP servers should use relative URLs to avoid the need to be coupled to the absolute path at which they are served. This means you must use trailing slashes on all paths with subpaths.

This reasoning is why the default behavior is to strip /proxy/<port> from the base path. If your application uses relative URLs and does not assume the absolute path at which it is being served, it will just work no matter what port you decide to serve it off or if you put it in behind code-server or any other proxy.

However, some prefer the cleaner aesthetic of no trailing slashes. Omitting the trailing slashes couples you to the base path, since you cannot use relative redirects correctly anymore. If you're okay with this tradeoff, use /absproxy instead and the path will be passed as is (e.g., /absproxy/3000/my-app-path).

[seankhliao]

sounds like you should just use /absproxy?

[spkane]

sounds like you should just use /absproxy?

No, that makes no difference. I am pretty sure that only prevents code-server from altering the request and stripping the proxy path.

I think the issue here is that pkgsite is not using relative paths.

e.g. https://github.com/golang/pkgsite/blob/6631f5443b15cc3c38d20c33131ac82c8e192ef7/static/frontend/frontend.tmpl#L56

This path won't work since it is really at /proxy/8080/static/ and /absproxy/8080/static/

[spkane]

cc/ @jmcshane

[findleyr]

CC @matloob