Add shorthand for --tail option

cli/command/container/logs.go

@@ -43,7 +43,7 @@ func NewLogsCommand(dockerCli command.Cli) *cobra.Command {
 	flags.SetAnnotation("until", "version", []string{"1.35"})
 	flags.BoolVarP(&opts.timestamps, "timestamps", "t", false, "Show timestamps")
 	flags.BoolVar(&opts.details, "details", false, "Show extra details provided to logs")
-	flags.StringVar(&opts.tail, "tail", "all", "Number of lines to show from the end of the logs")
+	flags.StringVarP(&opts.tail, "tail", "n", "all", "Number of lines to show from the end of the logs")
 	return cmd
 }
 

cli/command/service/logs.go

@@ -63,7 +63,7 @@ func newLogsCommand(dockerCli command.Cli) *cobra.Command {
 	flags.BoolVarP(&opts.timestamps, "timestamps", "t", false, "Show timestamps")
 	flags.BoolVar(&opts.details, "details", false, "Show extra details provided to logs")
 	flags.SetAnnotation("details", "version", []string{"1.30"})
-	flags.StringVar(&opts.tail, "tail", "all", "Number of lines to show from the end of the logs")
+	flags.StringVarP(&opts.tail, "tail", "n", "all", "Number of lines to show from the end of the logs")
 	return cmd
 }
 

contrib/completion/bash/docker

@@ -1672,17 +1672,17 @@ _docker_container_kill() {
 
 _docker_container_logs() {
 	case "$prev" in
-		--since|--tail|--until)
+		--since|--tail|-n|--until)
 			return
 			;;
 	esac
 
 	case "$cur" in
 		-*)
-			COMPREPLY=( $( compgen -W "--details --follow -f --help --since --tail --timestamps -t --until" -- "$cur" ) )
+			COMPREPLY=( $( compgen -W "--details --follow -f --help --since --tail -n --timestamps -t --until" -- "$cur" ) )
 			;;
 		*)
-			local counter=$(__docker_pos_first_nonflag '--since|--tail|--until')
+			local counter=$(__docker_pos_first_nonflag '--since|--tail|-n|--until')
 			if [ "$cword" -eq "$counter" ]; then
 				__docker_complete_containers_all
 			fi
@@ -3526,17 +3526,17 @@ _docker_service_inspect() {
 
 _docker_service_logs() {
 	case "$prev" in
-		--since|--tail)
+		--since|--tail|-n)
 			return
 			;;
 	esac
 
 	case "$cur" in
 		-*)
-			COMPREPLY=( $( compgen -W "--details --follow -f --help --no-resolve --no-task-ids --no-trunc --raw --since --tail --timestamps -t" -- "$cur" ) )
+			COMPREPLY=( $( compgen -W "--details --follow -f --help --no-resolve --no-task-ids --no-trunc --raw --since --tail -n --timestamps -t" -- "$cur" ) )
 			;;
 		*)
-			local counter=$(__docker_pos_first_nonflag '--since|--tail')
+			local counter=$(__docker_pos_first_nonflag '--since|--tail|-n')
 			if [ "$cword" -eq "$counter" ]; then
 				__docker_complete_services_and_tasks
 			fi

contrib/completion/fish/docker.fish

@@ -373,7 +373,7 @@ complete -c docker -A -f -n '__fish_seen_subcommand_from logs' -s f -l follow -d
 complete -c docker -A -f -n '__fish_seen_subcommand_from logs' -l help -d 'Print usage'
 complete -c docker -A -f -n '__fish_seen_subcommand_from logs' -s t -l timestamps -d 'Show timestamps'
 complete -c docker -A -f -n '__fish_seen_subcommand_from logs' -l since -d 'Show logs since timestamp'
-complete -c docker -A -f -n '__fish_seen_subcommand_from logs' -l tail -d 'Output the specified number of lines at the end of logs (defaults to all logs)'
+complete -c docker -A -f -n '__fish_seen_subcommand_from logs' -s n -l tail -d 'Output the specified number of lines at the end of logs (defaults to all logs)'
 complete -c docker -A -f -n '__fish_seen_subcommand_from logs' -a '(__fish_print_docker_containers running)' -d "Container"
 
 # network

contrib/completion/zsh/_docker

@@ -792,7 +792,7 @@ __docker_container_subcommand() {
                 "($help -f --follow)"{-f,--follow}"[Follow log output]" \
                 "($help -s --since)"{-s=,--since=}"[Show logs since this timestamp]:timestamp: " \
                 "($help -t --timestamps)"{-t,--timestamps}"[Show timestamps]" \
-                "($help)--tail=[Output the last K lines]:lines:(1 10 20 50 all)" \
+                "($help -n --tail)"{-n=,--tail=}"[Number of lines to show from the end of the logs]:lines:(1 10 20 50 all)" \
                 "($help -)*:containers:__docker_complete_containers" && ret=0
             ;;
         (ls|list)
@@ -2038,7 +2038,7 @@ __docker_service_subcommand() {
                 "($help)--no-task-ids[Do not include task IDs]" \
                 "($help)--no-trunc[Do not truncate output]" \
                 "($help)--since=[Show logs since timestamp]:timestamp: " \
-                "($help)--tail=[Number of lines to show from the end of the logs]:lines:(1 10 20 50 all)" \
+                "($help -n --tail)"{-n=,--tail=}"[Number of lines to show from the end of the logs]:lines:(1 10 20 50 all)" \
                 "($help -t --timestamps)"{-t,--timestamps}"[Show timestamps]" \
                 "($help -)1:service:__docker_complete_services" && ret=0
             ;;

docs/reference/commandline/logs.md

@@ -17,7 +17,7 @@ Options:
       --help           Print usage
       --since string   Show logs since timestamp (e.g. 2013-01-02T13:23:37Z) or relative (e.g. 42m for 42 minutes)
       --until string   Show logs before timestamp (e.g. 2013-01-02T13:23:37Z) or relative (e.g. 42m for 42 minutes)
-      --tail string    Number of lines to show from the end of the logs (default "all")
+  -n, --tail string    Number of lines to show from the end of the logs (default "all")
   -t, --timestamps     Show timestamps
 ```
 

docs/reference/commandline/service_logs.md

@@ -18,7 +18,7 @@ Options:
       --no-task-ids    Do not include task IDs in output
       --no-trunc        Do not truncate output
       --since string   Show logs since timestamp
-      --tail string    Number of lines to show from the end of the logs (default "all")
+  -n, --tail string    Number of lines to show from the end of the logs (default "all")
   -t, --timestamps     Show timestamps
 ```