View source for Golang private modules conf: meta tags, git+ssh, nginx

This configuration abstracts [[golang module path]], <br>
to provide access to private go modules over git+ssh,<br>
by setting dynamic html meta tags using nginx.

Go builds your executable on download, you don't need to build binaries in advance!


= Setup =
<blockquote>
* private package module-paths set to <code>example.com/x/${pkg}</code>
* nginx builds html meta-tag pointing to git repository when handling a request at <code>^example.com/x/[^]+$</code>
* git repository ip-address, user, identityfile all managed under the label <code>foo</code> in your <code>~/.ssh/config</code>
* assuming you've already setup git+ssh access to your git repositories somewhere on the internet. (see [[git ssh]])

== Workstation ==
<blockquote>
=== Add Private URL ===
<blockquote>
First, add the target URL to your <code>$GOPRIVATE</code> environment variable using one of the following methods:

<syntaxhighlight lang="bash">
# ~/.config/go/env

# you could also dump this in your ~/.zshrc
GOPRIVATE="example.com/x/*"
</syntaxhighlight>
</blockquote><!-- Add Private URL -->

=== Create Repo ===
<blockquote>
<syntaxhighlight lang="go">
// main.go

package main
import "fmt"
func main() {
	fmt.Println("hello")
}
</syntaxhighlight>

<syntaxhighlight lang="go">
// go.mod

module example.com/x/hello
go 1.18
</syntaxhighlight>

<syntaxhighlight lang="bash">
git commit -m 'init'
git push
</syntaxhighlight>
</blockquote><!-- Create Repo -->
</blockquote><!-- Workstation -->

== WebServer ==
<blockquote>
<syntaxhighlight lang="nginx">
# /usr/local/etc/nginx/nginx.conf

http {
    location / {
      root /usr/local/www/example.com;
      index index.html;
    }

    location ~ ^/x/(?<go_project>[^/]+)$ {
      root /usr/local/www/example.com;
      rewrite ^ /gopkg.html;
      sub_filter '{TARGET_PROJECT}' '$go_project'
      sub_filter_once off;
    }
}
</syntaxhighlight>

<syntaxhighlight lang="html">
<!-- /usr/local/www/example.com/gopkg.html -->

<html>
  <head>
    <meta name="go-import" content="example.com/x/{TARGET_PROJECT} git git+ssh://foo:/repos/{TARGET_PROJECT}">
  </head>
</html>
</syntaxhighlight>
</blockquote><!-- WebServer -->

== Package Consumers ==
<blockquote>
If your package is not configured as private, you'll HTTP-410 because the checksum was never added.
<syntaxhighlight lang="bash">
# ~/.config/go/env

GOPRIVATE="example.com/x/*"
</syntaxhighlight>

<syntaxhighlight lang="bash">
# ~/.ssh/config

Host foo
  Hostname example.com
  IdentityFile ~/.ssh/user
  User user
</syntaxhighlight>

<syntaxhighlight lang="go">
go install example.com/x/hello
</syntaxhighlight>
</blockquote><!-- Package Consumers -->
</blockquote><!-- Setup -->

= Troubleshooting =
<blockquote>
<syntaxhighlight lang="bash">
# is 'example/x/*' in your GOPRIVATE envvar?
go env | grep -e GOPRIVATE -e 'example/x'

# can you clone the project over ssh normally?
git clone foo:/repos/hello

# does the package/path look correct in your meta-tag?
curl https://example.com/x/foo

# debug logging
go install -v example/x/foo@latest

# debug logging for go, git+ssh
GIT_SSH_COMMAND='ssh -vvv' \
  go install -v example/x/foo@latest
</syntaxhighlight>
</blockquote><!-- Troubleshooting -->