Merge remote-tracking branch 'upstream/master' into no-ivar-in-modules

* upstream/master: (1723 commits)
  Resolve "Editor icons"
  Refactor issuable destroy action
  Ignore routes matching legacy_*_redirect in route specs
  Gitlab::Git::RevList and LfsChanges use lazy popen
  Gitlab::Git::Popen can lazily hand output to a block
  Merge branch 'master-i18n' into 'master'
  Remove unique validation from external_url in Environment
  Expose `duration` in Job API entity
  Add TimeCop freeze for DST and Regular time
  Harcode project visibility
  update a changelog
  Put a condition to old migration that adds fast_forward column to MRs
  Expose project visibility as CI variable
  fix flaky tests by removing unneeded clicks and focus actions
  fix flaky test in gfm_autocomplete_spec.rb
  Use Gitlab::Git operations for repository mirroring
  Encapsulate git operations for mirroring in Gitlab::Git
  Create a Wiki Repository's raw_repository properly
  Add `Gitlab::Git::Repository#fetch` command
  Fix Gitlab::Metrics::System#real_time and #monotonic_time doc
  ...

1 files changed, 70 insertions, 2 deletions

diff --git a/lib/gitlab/git/popen.rb b/lib/gitlab/git/popen.rb
index 054d45895a5..1ccca13ce2f 100644
--- a/lib/gitlab/git/popen.rb
+++ b/lib/gitlab/git/popen.rb
@@ -5,7 +5,9 @@ require 'open3'
 module Gitlab
   module Git
     module Popen
-      def popen(cmd, path, vars = {})
+      FAST_GIT_PROCESS_TIMEOUT = 15.seconds
+
+      def popen(cmd, path, vars = {}, lazy_block: nil)
         unless cmd.is_a?(Array)
           raise "System commands must be given as an array of strings"
         end
@@ -20,13 +22,79 @@ module Gitlab
           yield(stdin) if block_given?
           stdin.close
 
-          cmd_output << stdout.read
+          if lazy_block
+            return lazy_block.call(stdout.lazy)
+          else
+            cmd_output << stdout.read
+          end
+
           cmd_output << stderr.read
           cmd_status = wait_thr.value.exitstatus
         end
 
         [cmd_output, cmd_status]
       end
+
+      def popen_with_timeout(cmd, timeout, path, vars = {})
+        unless cmd.is_a?(Array)
+          raise "System commands must be given as an array of strings"
+        end
+
+        path ||= Dir.pwd
+        vars['PWD'] = path
+
+        unless File.directory?(path)
+          FileUtils.mkdir_p(path)
+        end
+
+        rout, wout = IO.pipe
+        rerr, werr = IO.pipe
+
+        pid = Process.spawn(vars, *cmd, out: wout, err: werr, chdir: path, pgroup: true)
+
+        begin
+          status = process_wait_with_timeout(pid, timeout)
+
+          # close write ends so we could read them
+          wout.close
+          werr.close
+
+          cmd_output = rout.readlines.join
+          cmd_output << rerr.readlines.join # Copying the behaviour of `popen` which merges stderr into output
+
+          [cmd_output, status.exitstatus]
+        rescue Timeout::Error => e
+          kill_process_group_for_pid(pid)
+
+          raise e
+        ensure
+          wout.close unless wout.closed?
+          werr.close unless werr.closed?
+
+          rout.close
+          rerr.close
+        end
+      end
+
+      def process_wait_with_timeout(pid, timeout)
+        deadline = timeout.seconds.from_now
+        wait_time = 0.01
+
+        while deadline > Time.now
+          sleep(wait_time)
+          _, status = Process.wait2(pid, Process::WNOHANG)
+
+          return status unless status.nil?
+        end
+
+        raise Timeout::Error, "Timeout waiting for process ##{pid}"
+      end
+
+      def kill_process_group_for_pid(pid)
+        Process.kill("KILL", -pid)
+        Process.wait(pid)
+      rescue Errno::ESRCH
+      end
     end
   end
 end