api: download from HOMEBREW_API_DOMAIN

Library/Homebrew/.rubocop.yml

@@ -41,7 +41,7 @@ Metrics/PerceivedComplexity:
 Metrics/MethodLength:
   Max: 232
 Metrics/ModuleLength:
-  Max: 466
+  Max: 473
   Exclude:
     # TODO: extract more of the bottling logic
     - "dev-cmd/bottle.rb"

Library/Homebrew/api.rb

@@ -17,7 +17,6 @@ module Homebrew
 
     module_function
 
-    API_DOMAIN = "https://formulae.brew.sh/api"
     HOMEBREW_CACHE_API = (HOMEBREW_CACHE/"api").freeze
 
     # Set a longer timeout just for large(r) files.
@@ -27,8 +26,13 @@ module Homebrew
     def fetch(endpoint)
       return cache[endpoint] if cache.present? && cache.key?(endpoint)
 
-      api_url = "#{API_DOMAIN}/#{endpoint}"
+      api_url = "#{Homebrew::EnvConfig.api_domain}/#{endpoint}"
       output = Utils::Curl.curl_output("--fail", api_url)
+      if !output.success? && Homebrew::EnvConfig.api_domain != HOMEBREW_API_DEFAULT_DOMAIN
+        # Fall back to the default API domain and try again
+        api_url = "#{HOMEBREW_API_DEFAULT_DOMAIN}/#{endpoint}"
+        output = Utils::Curl.curl_output("--fail", api_url)
+      end
       raise ArgumentError, "No file found at #{Tty.underline}#{api_url}#{Tty.reset}" unless output.success?
 
       cache[endpoint] = JSON.parse(output.stdout)
@@ -39,8 +43,9 @@ module Homebrew
     sig { params(endpoint: String, target: Pathname).returns(Hash) }
     def fetch_json_api_file(endpoint, target:)
       retry_count = 0
-      url = "#{API_DOMAIN}/#{endpoint}"
+      url = "#{Homebrew::EnvConfig.api_domain}/#{endpoint}"
-      curl_args = %W[--compressed --silent #{url}]
+      default_url = "#{HOMEBREW_API_DEFAULT_DOMAIN}/#{endpoint}"
+      curl_args = %w[--compressed --silent]
       curl_args.prepend("--time-cond", target) if target.exist? && !target.empty?
 
       begin
@@ -48,8 +53,17 @@ module Homebrew
           # Disable retries here, we handle them ourselves below.
           Utils::Curl.curl_download(*curl_args, to: target, max_time: JSON_API_MAX_TIME, retries: 0)
         rescue ErrorDuringExecution
+          if url == default_url
             raise unless target.exist?
             raise if target.empty?
+          elsif retry_count.zero? || !target.exist? || target.empty?
+            # Fall back to the default API domain and try again
+            # This block will be executed only once, because we set `url` to `default_url`
+            url = default_url
+            target.unlink if target.exist? && target.empty?
+
+            retry
+          end
 
           opoo "#{target.basename}: update failed, falling back to cached version."
         end

Library/Homebrew/brew.sh

@@ -601,6 +601,7 @@ then
   unset HOMEBREW_BOTTLE_DOMAIN
 fi
 
+HOMEBREW_API_DEFAULT_DOMAIN="https://formulae.brew.sh/api"
 HOMEBREW_BOTTLE_DEFAULT_DOMAIN="https://ghcr.io/v2/homebrew/core"
 
 HOMEBREW_USER_AGENT="${HOMEBREW_PRODUCT}/${HOMEBREW_USER_AGENT_VERSION} (${HOMEBREW_SYSTEM}; ${HOMEBREW_PROCESSOR} ${HOMEBREW_OS_USER_AGENT_VERSION})"
@@ -633,6 +634,7 @@ export HOMEBREW_MACOS_VERSION
 export HOMEBREW_MACOS_VERSION_NUMERIC
 export HOMEBREW_USER_AGENT
 export HOMEBREW_USER_AGENT_CURL
+export HOMEBREW_API_DEFAULT_DOMAIN
 export HOMEBREW_BOTTLE_DEFAULT_DOMAIN
 export HOMEBREW_MACOS_SYSTEM_RUBY_NEW_ENOUGH
 

Library/Homebrew/cmd/update.sh

@@ -778,14 +778,24 @@ EOS
       then
         INITIAL_JSON_BYTESIZE="$(wc -c "${HOMEBREW_CACHE}"/api/"${formula_or_cask}".json)"
       fi
+      JSON_URLS=()
+      if [[ -n "${HOMEBREW_API_DOMAIN}" && "${HOMEBREW_API_DOMAIN}" != "${HOMEBREW_API_DEFAULT_DOMAIN}" ]]
+      then
+        JSON_URLS=("${HOMEBREW_API_DOMAIN}/${formula_or_cask}.json")
+      fi
+      JSON_URLS+=("${HOMEBREW_API_DEFAULT_DOMAIN}/${formula_or_cask}.json")
+      for json_url in "${JSON_URLS[@]}"
+      do
         curl \
           "${CURL_DISABLE_CURLRC_ARGS[@]}" \
           --fail --compressed --silent --max-time 10 \
           --location --remote-time --output "${HOMEBREW_CACHE}/api/${formula_or_cask}.json" \
           --time-cond "${HOMEBREW_CACHE}/api/${formula_or_cask}.json" \
           --user-agent "${HOMEBREW_USER_AGENT_CURL}" \
-        "https://formulae.brew.sh/api/${formula_or_cask}.json"
+          "${json_url}"
         curl_exit_code=$?
+        [[ ${curl_exit_code} -eq 0 ]] && break
+      done
       if [[ ${curl_exit_code} -eq 0 ]]
       then
         CURRENT_JSON_BYTESIZE="$(wc -c "${HOMEBREW_CACHE}"/api/"${formula_or_cask}".json)"

Library/Homebrew/env_config.rb

@@ -15,6 +15,13 @@ module Homebrew
         description: "Additional Google Analytics tracking ID to emit user behaviour analytics to. " \
                      "For more information, see: <https://docs.brew.sh/Analytics>",
       },
+      HOMEBREW_API_DOMAIN:                       {
+        description:  "Use this URL as the download mirror for Homebrew JSON API. " \
+                      "If metadata files at that URL are temporarily unavailable, " \
+                      "the default API domain will be used as a fallback mirror.",
+        default_text: "`https://formulae.brew.sh/api`.",
+        default:      HOMEBREW_API_DEFAULT_DOMAIN,
+      },
       HOMEBREW_ARCH:                             {
         description: "Linux only: Pass this value to a type name representing the compiler's `-march` option.",
         default:     "native",

Library/Homebrew/global.rb

@@ -33,6 +33,7 @@ ActiveSupport::Inflector.inflections(:en) do |inflect|
   inflect.irregular "it", "they"
 end
 
+HOMEBREW_API_DEFAULT_DOMAIN = ENV.fetch("HOMEBREW_API_DEFAULT_DOMAIN").freeze
 HOMEBREW_BOTTLE_DEFAULT_DOMAIN = ENV.fetch("HOMEBREW_BOTTLE_DEFAULT_DOMAIN").freeze
 HOMEBREW_BREW_DEFAULT_GIT_REMOTE = ENV.fetch("HOMEBREW_BREW_DEFAULT_GIT_REMOTE").freeze
 HOMEBREW_CORE_DEFAULT_GIT_REMOTE = ENV.fetch("HOMEBREW_CORE_DEFAULT_GIT_REMOTE").freeze

Library/Homebrew/sorbet/rbi/hidden-definitions/hidden.rbi

@@ -4404,6 +4404,8 @@ module Homebrew::EnvConfig
 
   def self.all_proxy(); end
 
+  def self.api_domain(); end
+
   def self.arch(); end
 
   def self.artifact_domain(); end
@@ -5458,6 +5460,7 @@ class Object
   FORMULA_COMPONENT_PRECEDENCE_LIST = ::T.let(nil, ::T.untyped)
   GZIP_BUFFER_SIZE = ::T.let(nil, ::T.untyped)
   HIDDEN_DESC_PLACEHOLDER = ::T.let(nil, ::T.untyped)
+  HOMEBREW_API_DEFAULT_DOMAIN = ::T.let(nil, ::T.untyped)
   HOMEBREW_BOTTLES_EXTNAME_REGEX = ::T.let(nil, ::T.untyped)
   HOMEBREW_BOTTLE_DEFAULT_DOMAIN = ::T.let(nil, ::T.untyped)
   HOMEBREW_BREWED_CURL_PATH = ::T.let(nil, ::T.untyped)