Simplifify loading from remote url

ruby's OpenURI supports http_proxy and no_proxy (since 2.5),
so no need to carry our own implementation of it.

What's left is simplication of exception handling, but
I'm not so sure which exceptions are actually left to
be thrown

src/api/app/controllers/statistics/maintenance_statistics_controller.rb

@@ -7,7 +7,7 @@ def index
       if @project.is_a?(String)
         # FIXME: This could be simplified by redirecting to the remote instead
         remote_instance, remote_project = Project.find_remote_project(@project)
-        remote_response = Project::RemoteURL.load(remote_instance.remoteurl, maintenance_statistics_path(project: remote_project))
+        remote_response = Project::RemoteURL.load(remote_instance, maintenance_statistics_path(project: remote_project))
         if remote_response
           render xml: remote_response
         else

src/api/app/models/distribution.rb

@@ -40,13 +40,7 @@ def self.all_including_remotes
 
     Project.remote.each do |prj|
       body = Rails.cache.fetch("remote_distribution_#{prj.id}", expires_in: 1.hour) do
-        begin
-          Project::RemoteURL.load(prj.remoteurl, '/distributions.xml')
-        rescue OpenSSL::SSL::SSLError
-          # skip, but do not die if remote instance have invalid SSL
-          Rails.logger.error "Remote instance #{prj.remoteurl} has no valid SSL certificate"
-          next
-        end
+        Project::RemoteURL.load(prj, '/distributions.xml')
       end
       next if body.blank? # don't let broken remote instances break us
       xmlhash = Xmlhash.parse(body)

src/api/app/models/project.rb

@@ -166,12 +166,7 @@ def self.remote_image_templates
 
   def self.load_from_remote(project, path)
     Rails.cache.fetch("remote_image_templates_#{project.id}", expires_in: 1.hour) do
-      begin
-        Project::RemoteURL.load(project.remoteurl, path)
-      rescue OpenSSL::SSL::SSLError
-        Rails.logger.error "Remote instance #{project.remoteurl} has no valid SSL certificate"
-        nil
-      end
+      Project::RemoteURL.load(project, path)
     end
   end
 

src/api/app/models/project/remote_url.rb

@@ -1,39 +1,19 @@
-module Project::RemoteURL
-
-  def load(remote_uri, path)
-    uri = URI.parse(remote_uri + path)
-    http = nil
-    content = nil
-    proxyuri = ENV['http_proxy']
-    proxyuri = CONFIG['http_proxy'] if CONFIG['http_proxy'].present?
-    noproxy = ENV['no_proxy']
-    noproxy = CONFIG['no_proxy'] if CONFIG['no_proxy'].present?
-
-    noproxy_applies = false
-    if noproxy
-      np_split = noproxy.split(',')
-      noproxy_applies = np_split.any? { |np| uri.host.end_with?(np.strip) }
+class Project::RemoteURL
+  def self.load(remote_project, path)
+    uri = URI.parse(remote_project.remoteurl + path)
+    # prefer environment variables if set
+    if ENV['http_proxy'].blank?
+      ENV['http_proxy'] = Configuration.first.http_proxy
     end
-
-    if proxyuri && noproxy_applies == false
-      proxy = URI.parse(proxyuri)
-      proxy_user, proxy_pass = proxy.userinfo.split(/:/) if proxy.userinfo
-      http = Net::HTTP::Proxy(proxy.host, proxy.port, proxy_user, proxy_pass).new(uri.host, uri.port)
-    else
-      http = Net::HTTP.new(uri.host, uri.port)
+    if ENV['no_proxy'].blank?
+      ENV['no_proxy'] = Configuration.first.no_proxy
     end
-    http.use_ssl = (uri.scheme == 'https')
     begin
-      http.start
-      response = http.get uri.request_uri
-      content = response.body if response.is_a?(Net::HTTPSuccess)
-    rescue SocketError, Errno::EINTR, Errno::EPIPE, EOFError, Net::HTTPBadResponse, IOError, Errno::ENETUNREACH,
-           Errno::ETIMEDOUT, Errno::ECONNREFUSED, Timeout::Error => err
-      Rails.logger.debug "#{err} when fetching #{uri}"
-      http = nil
+      uri.open.read
+    rescue OpenURI::HTTPError, SocketError, Errno::EINTR, Errno::EPIPE, EOFError, Net::HTTPBadResponse, IOError, Errno::ENETUNREACH,
+           Errno::ETIMEDOUT, Errno::ECONNREFUSED, Timeout::Error, OpenSSL::SSL::SSLError => err
+      Rails.logger.debug "#{err} when fetching #{path} from #{remote_project.remoteurl}"
+      nil
     end
-    http.finish if http && http.started?
-    content
   end
-
 end