feat(github): perform authenticated GitHub API requests when GITHUB_TOKEN env var is set

This should let people on shared connections use the script if they
have a GitHub Personal Access Token available in the GITHUB_TOKEN
environment variable.

When making unauthenticated API requests to GitHub, requests are rate
limited to 60 requests per hour based on source IP address. Hence on
shared connections the rate limit may easily be exceeded.

When making authenticated API requests to GitHub, up to 5000 requests
per hour is allowed, based on the authenticated user rather than source
IP address.

README.md

@@ -78,6 +78,7 @@ Options:
         --[no-]rsvg                  Enable/disable SVG image support via librsvg (default: enabled)
         --no-titlebar                Apply no-titlebar patch (default: disabled)
         --no-frame-refocus           Apply no-frame-refocus patch (default: disabled)
+        --[no-]github-auth           Make authenticated GitHub API requests if GITHUB_TOKEN environment variable is set.(default: enabled)
         --work-dir DIR               Specify a working directory where tarballs, sources, and builds will be stored and worked with
         --plan FILE                  Follow given plan file, instead of using given git ref/sha
 ```

build-emacs-for-macos

@@ -71,9 +71,8 @@ end
 class Build
   include Output
 
-  DOWNLOAD_URL = 'https://github.com/emacs-mirror/emacs/tarball/%s'
-  LATEST_URL = 'https://api.github.com/repos/emacs-mirror/emacs/commits/%s'
-  NATIVE_COMP_REF_REGEXP = %r{^feature/native-comp}.freeze
+  EMACS_MIRROR_REPO = 'emacs-mirror/emacs'
+  DOWNLOAD_URL = 'https://api.github.com/repos/emacs-mirror/emacs/tarball/%s'
 
   attr_reader :root_dir
   attr_reader :source_dir
@@ -162,8 +161,20 @@ class Build
 
     info 'Downloading tarball from GitHub. This could take a while, ' \
          'please be patient.'
-    result = run_cmd('curl', '-L', url, '-o', target)
-    err 'Download failed.' unless result
+
+    args = ['curl', '-L', url, '-o', target]
+    log_args = args.clone
+
+    if options[:github_auth] && ENV['GITHUB_TOKEN']
+      args = [args[0]] +
+             ['-H', "Authorization: Token #{ENV['GITHUB_TOKEN']}"] + args[1..-1]
+      log_args = [log_args[0]] +
+                 ['-H', '"Authorization: Token $GITHUB_TOKEN"'] +
+                 log_args[1..-1]
+    end
+
+    out "CMD: #{log_args.join(' ')}"
+    system(*args) || err("Exit code: #{$CHILD_STATUS.exitstatus}")
 
     target
   end
@@ -442,8 +453,9 @@ class Build
 
     ref_sha = options[:git_sha] || ref
     info "Fetching info for git ref: #{ref_sha}"
-    url = format(LATEST_URL, ref_sha)
-    commit_json = http_get(url)
+    commit_json = github_api_get(
+      "/repos/#{EMACS_MIRROR_REPO}/commits/#{ref_sha}"
+    )
     err "Failed to get commit info about: #{ref_sha}" if commit_json.nil?
 
     commit = JSON.parse(commit_json)
@@ -456,8 +468,18 @@ class Build
     @meta = meta
   end
 
-  def http_get(url)
-    response = Net::HTTP.get_response(URI.parse(url))
+  def github_api_get(uri)
+    uri = URI.join('https://api.github.com/', uri)
+
+    http = Net::HTTP.new(uri.hostname, uri.port)
+    http.use_ssl = true if uri.scheme == 'https'
+
+    request = Net::HTTP::Get.new(uri)
+    if options[:github_auth] && ENV['GITHUB_TOKEN']
+      request['Authorization'] = "Token #{ENV['GITHUB_TOKEN']}"
+    end
+
+    response = http.request(request)
     return unless response.code == '200'
 
     response.body
@@ -860,7 +882,8 @@ if __FILE__ == $PROGRAM_NAME
     native_full_aot: false,
     parallel: Etc.nprocessors,
     rsvg: true,
-    xwidgets: true
+    xwidgets: true,
+    github_auth: true
   }
 
   begin
@@ -919,6 +942,13 @@ if __FILE__ == $PROGRAM_NAME
         cli_options[:no_frame_refocus] = true
       end
 
+      opts.on('--[no-]github-auth',
+              'Make authenticated GitHub API requests if GITHUB_TOKEN ' \
+              'environment variable is set.' \
+              '(default: enabled)') do |v|
+        cli_options[:github_auth] = v
+      end
+
       opts.on('--work-dir DIR',
               'Specify a working directory where tarballs, sources, and ' \
               'builds will be stored and worked with') do |v|