Refactor usage of docker version in bash completion

This preapares bash completion for more context sensitivity:

- experimental cli features
- orchestrator specific features

Also renames _daemon_ to _server_ where used in context of `docker version`
because the fields there are grouped unter _Server_.

Signed-off-by: Harald Albers <github@albersweb.de>

contrib/completion/bash/docker

@@ -563,23 +563,31 @@ __docker_append_to_completions() {
 	COMPREPLY=( ${COMPREPLY[@]/%/"$1"} )
 }
 
-# __docker_daemon_is_experimental tests whether the currently configured Docker
+# __docker_fetch_info fetches information about the configured Docker server and updates
-# daemon runs in experimental mode. If so, the function exits with 0 (true).
+# several variables with the results.
-# Otherwise, or if the result cannot be determined, the exit value is 1 (false).
+# The result is cached for the duration of one invocation of bash completion.
-__docker_daemon_is_experimental() {
+__docker_fetch_info() {
-	[ "$(__docker_q version -f '{{.Server.Experimental}}')" = "true" ]
+	if [ -z "$info_fetched" ] ; then
+		read -r server_experimental server_os < <(__docker_q version -f '{{.Server.Experimental}} {{.Server.Os}}')
+		info_fetched=true
+	fi
 }
 
-# __docker_daemon_os_is tests whether the currently configured Docker daemon runs
+# __docker_server_is_experimental tests whether the currently configured Docker
+# server runs in experimental mode. If so, the function exits with 0 (true).
+# Otherwise, or if the result cannot be determined, the exit value is 1 (false).
+__docker_server_is_experimental() {
+	__docker_fetch_info
+	[ "$server_experimental" = "true" ]
+}
+
+# __docker_server_os_is tests whether the currently configured Docker server runs
 # on the operating system passed in as the first argument.
-# It does so by querying the daemon for its OS. The result is cached for the duration
-# of one invocation of bash completion so that this function can be used to test for
-# several different operating systems without additional costs.
 # Known operating systems: linux, windows.
-__docker_daemon_os_is() {
+__docker_server_os_is() {
 	local expected_os="$1"
-	local actual_os=${daemon_os=$(__docker_q version -f '{{.Server.Os}}')}
+	__docker_fetch_info
-	[ "$actual_os" = "$expected_os" ]
+	[ "$server_os" = "$expected_os" ]
 }
 
 # __docker_stack_orchestrator_is tests whether the client is configured to use
@@ -1128,7 +1136,7 @@ _docker_docker() {
 		*)
 			local counter=$( __docker_pos_first_nonflag "$(__docker_to_extglob "$global_options_with_args")" )
 			if [ "$cword" -eq "$counter" ]; then
-				__docker_daemon_is_experimental && commands+=(${experimental_commands[*]})
+				__docker_server_is_experimental && commands+=(${experimental_commands[*]})
 				COMPREPLY=( $( compgen -W "${commands[*]} help" -- "$cur" ) )
 			fi
 			;;
@@ -1837,14 +1845,14 @@ _docker_container_run_and_create() {
 		--volume -v
 		--workdir -w
 	"
-	__docker_daemon_os_is windows && options_with_args+="
+	__docker_server_os_is windows && options_with_args+="
 		--cpu-count
 		--cpu-percent
 		--io-maxbandwidth
 		--io-maxiops
 		--isolation
 	"
-	__docker_daemon_is_experimental && options_with_args+="
+	__docker_server_is_experimental && options_with_args+="
 		--platform
 	"
 
@@ -1960,7 +1968,7 @@ _docker_container_run_and_create() {
 			return
 			;;
 		--isolation)
-			if __docker_daemon_os_is windows ; then
+			if __docker_server_os_is windows ; then
 				__docker_complete_isolation
 				return
 			fi
@@ -2071,12 +2079,12 @@ _docker_container_start() {
 	__docker_complete_detach_keys && return
 	case "$prev" in
 		--checkpoint)
-			if __docker_daemon_is_experimental ; then
+			if __docker_server_is_experimental ; then
 				return
 			fi
 			;;
 		--checkpoint-dir)
-			if __docker_daemon_is_experimental ; then
+			if __docker_server_is_experimental ; then
 				_filedir -d
 				return
 			fi
@@ -2086,7 +2094,7 @@ _docker_container_start() {
 	case "$cur" in
 		-*)
 			local options="--attach -a --detach-keys --help --interactive -i"
-			__docker_daemon_is_experimental && options+=" --checkpoint --checkpoint-dir"
+			__docker_server_is_experimental && options+=" --checkpoint --checkpoint-dir"
 			COMPREPLY=( $( compgen -W "$options" -- "$cur" ) )
 			;;
 		*)
@@ -2449,7 +2457,7 @@ _docker_daemon() {
 }
 
 _docker_deploy() {
-	__docker_daemon_is_experimental && _docker_stack_deploy
+	__docker_server_is_experimental && _docker_stack_deploy
 }
 
 _docker_diff() {
@@ -2535,7 +2543,7 @@ _docker_image_build() {
 		--target
 		--ulimit
 	"
-	__docker_daemon_os_is windows && options_with_args+="
+	__docker_server_os_is windows && options_with_args+="
 		--isolation
 	"
 
@@ -2549,7 +2557,7 @@ _docker_image_build() {
 		--quiet -q
 		--rm
 	"
-	if __docker_daemon_is_experimental ; then
+	if __docker_server_is_experimental ; then
 		options_with_args+="
 			--platform
 		"
@@ -2584,7 +2592,7 @@ _docker_image_build() {
 			return
 			;;
 		--isolation)
-			if __docker_daemon_os_is windows ; then
+			if __docker_server_os_is windows ; then
 				__docker_complete_isolation
 				return
 			fi
@@ -2779,7 +2787,7 @@ _docker_image_pull() {
 	case "$cur" in
 		-*)
 			local options="--all-tags -a --disable-content-trust=false --help"
-			__docker_daemon_is_experimental && options+=" --platform"
+			__docker_server_is_experimental && options+=" --platform"
 
 			COMPREPLY=( $( compgen -W "$options" -- "$cur" ) )
 			;;
@@ -3431,7 +3439,7 @@ _docker_service_update_and_create() {
 		--user -u
 		--workdir -w
 	"
-	__docker_daemon_os_is windows && options_with_args+="
+	__docker_server_os_is windows && options_with_args+="
 		--credential-spec
 	"
 
@@ -4451,7 +4459,7 @@ _docker_stack_deploy() {
 	case "$cur" in
 		-*)
 			local options="--compose-file -c --help --orchestrator"
-			__docker_daemon_is_experimental && __docker_stack_orchestrator_is swarm && options+=" --bundle-file"
+			__docker_server_is_experimental && __docker_stack_orchestrator_is swarm && options+=" --bundle-file"
 			__docker_stack_orchestrator_is kubernetes && options+=" --kubeconfig --namespace"
 			__docker_stack_orchestrator_is swarm && options+=" --prune --resolve-image --with-registry-auth"
 			COMPREPLY=( $( compgen -W "$options" -- "$cur" ) )
@@ -5098,11 +5106,13 @@ _docker() {
 		--tlskey
 	"
 
-	local host config daemon_os
+	# variables to cache server info, populated on demand for performance reasons
-
+	local info_fetched server_experimental server_os
 	# variables to cache client info, populated on demand for performance reasons
 	local stack_orchestrator_is_kubernetes stack_orchestrator_is_swarm
 
+	local host config
+
 	COMPREPLY=()
 	local cur prev words cword
 	_get_comp_words_by_ref -n : cur prev words cword