Add grep's context option to show lines before and after a match

lib/kamal/commands/app/logging.rb

@@ -1,17 +1,17 @@
 module Kamal::Commands::App::Logging
-  def logs(version: nil, since: nil, lines: nil, grep: nil)
+  def logs(version: nil, since: nil, lines: nil, grep: nil, context: nil)
     pipe \
       version ? container_id_for_version(version) : current_running_container_id,
       "xargs docker logs#{" --since #{since}" if since}#{" --tail #{lines}" if lines} 2>&1",
-      ("grep '#{grep}'" if grep)
+      ("grep '#{grep}'#{" -C #{context}" if context}" if grep)
   end
 
-  def follow_logs(host:, lines: nil, grep: nil)
+  def follow_logs(host:, lines: nil, grep: nil, context: nil)
     run_over_ssh \
       pipe(
         current_running_container_id,
         "xargs docker logs --timestamps#{" --tail #{lines}" if lines} --follow 2>&1",
-        (%(grep "#{grep}") if grep)
+        (%(grep "#{grep}"#{" -C #{context}" if context}) if grep)
       ),
       host: host
   end