Added support for pulling new images before starting the container.

dup.rb

@@ -31,6 +31,7 @@ def get_sample(name="container")
 		  restart: always
 		  command: "/bin/bash"
 		  build: "/data/dir"
+		  pull: false
 		  
 		  ports:
 		    - "1234:1234"
@@ -81,6 +82,7 @@ def action_help
 	puts "-n, --dry-run           Don't execute any commands."
 	puts "-s, --sample            Outputs a sample yml file."
 	puts "-c, --create            Create a new container yml file."
+	puts "-p, --pull              (Try to) Pull the image(s) before starting the container."
 	exit 1
 end
 
@@ -147,6 +149,9 @@ def action_run(container, file)
 			end
 		end
 		
+		if data["pull"] || $pull
+			run("docker pull #{data["image"].shellescape}", true)
+		end
 		run("docker rm -f #{(data["container_name"] || key).shellescape}", true)
 		run(cmd.compact.join(" "))
 		
@@ -157,12 +162,14 @@ end
 action = :run
 container = nil
 $dry_run = false
+$pull = false
 
 opts = GetoptLong.new(
 	[ '--sample', '-s', GetoptLong::NO_ARGUMENT ],
 	[ '--create', '-c', GetoptLong::NO_ARGUMENT ],
 	[ '--help', '-h', GetoptLong::NO_ARGUMENT ],
-	[ '--dry-run', '-n', GetoptLong::NO_ARGUMENT ]
+	[ '--dry-run', '-n', GetoptLong::NO_ARGUMENT ],
+	[ '--pull', '-p', GetoptLong::NO_ARGUMENT ]
 )
 
 opts.each do |opt, arg|
@@ -176,6 +183,8 @@ opts.each do |opt, arg|
 		when '--dry-run'
 			puts "Dry-run. Not going to execute any command."
 			$dry_run = true
+		when '--pull'
+			$pull = true
 	end
 end