Add initial set of tools

 - rsync-cat: rsync-to-stdout utility
 - gm-lag: displays the current lag of a mirror

1 files changed, 89 insertions, 0 deletions

diff --git a/lib/mirror_toolkit.rb b/lib/mirror_toolkit.rb
new file mode 100644
index 0000000..cc53090
--- /dev/null
+++ b/lib/mirror_toolkit.rb
@@ -0,0 +1,89 @@
+require 'open3'
+require 'time'
+require 'net/http'
+
+# Mirror toolkit functionality and other shared stuff
+module MirrorToolkit
+  RSYNC_TIMESTAMP_FILE = '/gentoo-portage/metadata/timestamp'
+  DISTFILES_TIMESTAMP_FILE = '/distfiles/timestamp.mirmon'
+
+  TYPE_RSYNC = 1
+  TYPE_DISTFILES = 2
+
+  module_function
+
+  # Calls `rsync_cat` to fetch a file from rsync
+  def rsync_cat(uri)
+    rsync_cat = File.join(File.dirname(__FILE__), '..', 'bin', 'rsync-cat')
+    stdin, stdout, stderr, wait_thr = Open3.popen3(rsync_cat, uri)
+    stdin.close
+
+    if wait_thr.value == 0
+      return stdout.gets
+    else
+      fail "Rsync call unsuccessful: '#{stderr.gets.chomp}'"
+    end
+  end
+
+  # Fetches a URI from any of the Gentoo mirror types
+  def remote_fetch(url)
+    case url.scheme
+    when 'rsync'
+      rsync_cat(url.to_s)
+    when 'http', 'https', 'ftp'
+      Net::HTTP.get(url)
+    else
+      fail 'Unknown URI scheme.'
+    end
+  end
+
+  # Tries to return a Time object for every kind of timestamp used on Gentoo mirrors
+  def parse_timestamp(ts)
+    if ts.numeric?
+      Time.at(ts.to_i).utc
+    else
+      Time.parse(ts).utc
+    end
+  end
+
+  # Returns a URI object where to find the timestamp for the given url and mirror type.
+  def get_timestamp_url(url, type)
+    mirror = URI(url)
+
+    case mirror.scheme
+    when 'rsync'
+      if type == TYPE_RSYNC
+        mirror.path = MirrorToolkit::RSYNC_TIMESTAMP_FILE
+      elsif type == TYPE_DISTFILES
+        mirror.path += MirrorToolkit::DISTFILES_TIMESTAMP_FILE
+      end
+    when 'http', 'https', 'ftp'
+      mirror.path = MirrorToolkit::DISTFILES_TIMESTAMP_FILE
+    end
+
+    mirror
+  end
+
+  # Returns the number of seconds a mirror is lagging behind, or nil if it cannot be determined.
+  def get_lag(url, type)
+    Time.now.utc - parse_timestamp(remote_fetch(get_timestamp_url(url, type)))
+  rescue
+    nil
+  end
+
+  # Renders seconds as a nice human-printable string
+  def humanize_seconds(secs)
+    [[60, :seconds], [60, :minutes], [24, :hours], [1000, :days]].map do |count, name|
+      if secs > 0
+        secs, n = secs.divmod(count)
+        "#{n.to_i} #{name}"
+      end
+    end.compact.reverse.join(' ')
+  end
+end
+
+class String
+  def numeric?
+    true if Float(self) rescue false
+  end
+end