Fix fish autocompletion with custom ps output

In the docker config.json, if `psFormat` or `imagesFormat` is set to a
non-standard format, it breaks autocompletion.

This fixes the issue by using a custom format.

Signed-off-by: Chris Gibson <chris@chrisg.io>

contrib/completion/fish/docker.fish

@@ -26,20 +26,20 @@ end
 function __fish_print_docker_containers --description 'Print a list of docker containers' -a select
     switch $select
         case running
-            docker ps -a --no-trunc | command awk 'NR>1' | command awk 'BEGIN {FS="  +"}; $5 ~ "^Up" {print $1 "\n" $(NF)}' | tr ',' '\n'
+            docker ps -a --no-trunc --filter status=running --format "{{.ID}}\n{{.Names}}" | tr ',' '\n'
         case stopped
-            docker ps -a --no-trunc | command awk 'NR>1' | command awk 'BEGIN {FS="  +"}; $5 ~ "^Exit" {print $1 "\n" $(NF)}' | tr ',' '\n'
+            docker ps -a --no-trunc --filter status=exited --format "{{.ID}}\n{{.Names}}" | tr ',' '\n'
         case all
-            docker ps -a --no-trunc | command awk 'NR>1' | command awk 'BEGIN {FS="  +"}; {print $1 "\n" $(NF)}' | tr ',' '\n'
+            docker ps -a --no-trunc --format "{{.ID}}\n{{.Names}}" | tr ',' '\n'
     end
 end
 
 function __fish_print_docker_images --description 'Print a list of docker images'
-    docker images | command awk 'NR>1' | command grep -v '<none>' | command awk '{print $1":"$2}'
+    docker images --format "{{.Repository}}:{{.Tag}}" | command grep -v '<none>'
 end
 
 function __fish_print_docker_repositories --description 'Print a list of docker repositories'
-    docker images | command awk 'NR>1' | command grep -v '<none>' | command awk '{print $1}' | command sort | command uniq
+    docker images --format "{{.Repository}}" | command grep -v '<none>' | command sort | command uniq
 end
 
 # common options