Remove fastly http purge feature flag and conditional behavior (#16903)

* Always use purge, never post, to fastly

* Remove unneeded feature flag

app/services/edge_cache/bust/fastly.rb

@@ -4,18 +4,10 @@ module EdgeCache
       # [@forem/systems] Fastly-enabled Forems don't need "flexible" domains.
       def self.call(path)
         api_key = ApplicationConfig["FASTLY_API_KEY"]
-        return fastly_purge(api_key, path) if FeatureFlag.enabled?(:fastly_http_purge)
 
-        fastly_post(api_key, path)
+        fastly_purge(api_key, path)
       end
 
-      def self.fastly_post(api_key, path)
-        urls(path).map do |url|
-          HTTParty.post("https://api.fastly.com/purge/#{url}", headers: { "Fastly-Key" => api_key })
-        end
-      end
-      private_class_method :fastly_post
-
       def self.fastly_purge(api_key, path)
         fastly = ::Fastly.new(api_key: api_key)
 

lib/data_update_scripts/20220317151317_remove_fastly_http_purge_flag.rb

@@ -0,0 +1,7 @@
+module DataUpdateScripts
+  class RemoveFastlyHttpPurgeFlag
+    def run
+      FeatureFlag.remove(:fastly_http_purge)
+    end
+  end
+end

spec/lib/data_update_scripts/remove_fastly_http_purge_flag_spec.rb

@@ -0,0 +1,21 @@
+require "rails_helper"
+require Rails.root.join(
+  "lib/data_update_scripts/20220317151317_remove_fastly_http_purge_flag.rb",
+)
+
+describe DataUpdateScripts::RemoveFastlyHttpPurgeFlag do
+  it "removes the feature flag if present" do
+    FeatureFlag.add(:fastly_http_purge)
+
+    described_class.new.run
+
+    expect(FeatureFlag.exist?(:fastly_http_purge)).to be false
+  end
+
+  it "is safe to run twice" do
+    # this is the same as "does nothing if flag not present"
+    2.times { described_class.new.run }
+
+    expect(FeatureFlag.exist?(:fastly_http_purge)).to be false
+  end
+end