Merge pull request #10834 from samford/livecheck-replace-open-uri-with-curl

Livecheck: Replace OpenURI#open with Curl

Library/Homebrew/livecheck/strategy.rb

@@ -19,7 +19,68 @@ module Homebrew
       # the middle of this range. Strategies with a priority of 0 (or lower)
       # are ignored.
       DEFAULT_PRIORITY = 5
-      private_constant :DEFAULT_PRIORITY
+
+      # cURL's default `--connect-timeout` value can be up to two minutes, so
+      # we need to use a more reasonable duration (in seconds) to avoid a
+      # lengthy wait when a connection can't be established.
+      CURL_CONNECT_TIMEOUT = 10
+
+      # cURL does not set a default `--max-time` value, so we provide a value
+      # to ensure cURL will time out in a reasonable amount of time.
+      CURL_MAX_TIME = CURL_CONNECT_TIMEOUT + 5
+
+      # The `curl` process will sometimes hang indefinitely (despite setting
+      # the `--max-time` argument) and it needs to be quit for livecheck to
+      # continue. This value is used to set the `timeout` argument on
+      # `Utils::Curl` method calls in `Strategy`.
+      CURL_PROCESS_TIMEOUT = CURL_MAX_TIME + 5
+
+      # Baseline `curl` arguments used in `Strategy` methods.
+      DEFAULT_CURL_ARGS = [
+        # Follow redirections to handle mirrors, relocations, etc.
+        "--location",
+        "--connect-timeout", CURL_CONNECT_TIMEOUT,
+        "--max-time", CURL_MAX_TIME
+      ].freeze
+
+      # `curl` arguments used in `Strategy#page_headers` method.
+      PAGE_HEADERS_CURL_ARGS = ([
+        # We only need the response head (not the body)
+        "--head",
+        # Some servers may not allow a HEAD request, so we use GET
+        "--request", "GET",
+        "--silent"
+      ] + DEFAULT_CURL_ARGS).freeze
+
+      # `curl` arguments used in `Strategy#page_content` method.
+      PAGE_CONTENT_CURL_ARGS = ([
+        "--compressed",
+        # Include HTTP response headers in output, so we can identify the
+        # final URL after any redirections
+        "--include",
+      ] + DEFAULT_CURL_ARGS).freeze
+
+      # Baseline `curl` options used in `Strategy` methods.
+      DEFAULT_CURL_OPTIONS = {
+        print_stdout: false,
+        print_stderr: false,
+        debug:        false,
+        verbose:      false,
+        timeout:      CURL_PROCESS_TIMEOUT,
+        retry:        false,
+      }.freeze
+
+      # HTTP response head(s) and body are typically separated by a double
+      # `CRLF` (whereas HTTP header lines are separated by a single `CRLF`).
+      # In rare cases, this can also be a double newline (`\n\n`).
+      HTTP_HEAD_BODY_SEPARATOR = "\r\n\r\n"
+
+      # The `#strategies` method expects `Strategy` constants to be strategies,
+      # so constants we create need to be private for this to work properly.
+      private_constant :DEFAULT_PRIORITY, :CURL_CONNECT_TIMEOUT, :CURL_MAX_TIME,
+                       :CURL_PROCESS_TIMEOUT, :DEFAULT_CURL_ARGS,
+                       :PAGE_HEADERS_CURL_ARGS, :PAGE_CONTENT_CURL_ARGS,
+                       :DEFAULT_CURL_OPTIONS, :HTTP_HEAD_BODY_SEPARATOR
 
       # Creates and/or returns a `@strategies` `Hash`, which maps a snake
       # case strategy name symbol (e.g. `:page_match`) to the associated
@@ -87,20 +148,10 @@ module Homebrew
         headers = []
 
         [:default, :browser].each do |user_agent|
-          args = [
-            "--head",                 # Only work with the response headers
-            "--request", "GET",       # Use a GET request (instead of HEAD)
-            "--silent",               # Silent mode
-            "--location",             # Follow redirects
-            "--connect-timeout", "5", # Max time allowed for connection (secs)
-            "--max-time", "10"        # Max time allowed for transfer (secs)
-          ]
-
           stdout, _, status = curl_with_workarounds(
-            *args, url,
-            print_stdout: false, print_stderr: false,
-            debug: false, verbose: false,
-            user_agent: user_agent, retry: false
+            *PAGE_HEADERS_CURL_ARGS, url,
+            **DEFAULT_CURL_OPTIONS,
+            user_agent: user_agent
           )
 
           while stdout.match?(/\AHTTP.*\r$/)
@@ -119,6 +170,8 @@ module Homebrew
 
       # Fetches the content at the URL and returns a hash containing the
       # content and, if there are any redirections, the final URL.
+      # If `curl` encounters an error, the hash will contain a `:messages`
+      # array with the error message instead.
       #
       # @param url [String] the URL of the content to check
       # @return [Hash]
@@ -126,18 +179,45 @@ module Homebrew
       def self.page_content(url)
         original_url = url
 
-        # Manually handling `URI#open` redirections allows us to detect the
-        # resolved URL while also supporting HTTPS to HTTP redirections (which
-        # are normally forbidden by `OpenURI`).
-        begin
-          content = URI.parse(url).open(redirect: false, &:read)
-        rescue OpenURI::HTTPRedirect => e
-          url = e.uri.to_s
-          retry
+        stdout, stderr, status = curl_with_workarounds(
+          *PAGE_CONTENT_CURL_ARGS, url,
+          **DEFAULT_CURL_OPTIONS
+        )
+
+        unless status.success?
+          /^(?<error_msg>curl: \(\d+\) .+)/ =~ stderr
+          return {
+            messages: [error_msg.presence || "cURL failed without an error"],
+          }
+        end
+
+        # stdout contains the header information followed by the page content.
+        # We use #scrub here to avoid "invalid byte sequence in UTF-8" errors.
+        output = stdout.scrub
+
+        # Separate the head(s)/body and identify the final URL (after any
+        # redirections)
+        max_iterations = 5
+        iterations = 0
+        output = output.lstrip
+        while output.match?(%r{\AHTTP/[\d.]+ \d+}) && output.include?(HTTP_HEAD_BODY_SEPARATOR)
+          iterations += 1
+          raise "Too many redirects (max = #{max_iterations})" if iterations > max_iterations
+
+          head_text, _, output = output.partition(HTTP_HEAD_BODY_SEPARATOR)
+          output = output.lstrip
+
+          location = head_text[/^Location:\s*(.*)$/i, 1]
+          next if location.blank?
+
+          location.chomp!
+          # Convert a relative redirect URL to an absolute URL
+          location = URI.join(url, location) unless location.match?(PageMatch::URL_MATCH_REGEX)
+          final_url = location
         end
 
-        data = { content: content }
-        data[:final_url] = url unless url == original_url
+        data = { content: output }
+        data[:final_url] = final_url if final_url.present? && final_url != original_url
         data
       end
     end

Library/Homebrew/livecheck/strategy/page_match.rb

 # typed: true
 # frozen_string_literal: true
 
-require "open-uri"
-
 module Homebrew
   module Livecheck
     module Strategy