new: [compose-core] add ``--get-available-actions`` commands

bin/compose-core

@@ -2065,6 +2065,34 @@ get_compose_relations () {
 export -f get_compose_relations
 
 
+get_all_services() {
+    local cache_file="$state_tmpdir/$FUNCNAME.cache.$(H "$ALL_RELATIONS")" \
+          s rn ts rc td services
+    if [ -e "$cache_file" ]; then
+        #debug "$FUNCNAME: SESSION cache hit $1"
+        cat "$cache_file"
+        return 0
+    fi
+
+    if [ -z "$ALL_RELATIONS" ]; then
+        err "Can't access global \$ALL_RELATIONS"
+        return 1
+    fi
+
+    declare -A services
+    while read-0 s _ ts _ _; do
+        for service in "$s" "$ts"; do
+            [ "${services[$service]}" ] && continue
+            services["$service"]=1
+            echo "$service"
+        done
+    done < <(cat "$ALL_RELATIONS") > "$cache_file"
+
+    cat "$cache_file"
+}
+export -f get_all_services
+
+
 get_service_relations () {
     local service="$1" cache_file="$state_tmpdir/$FUNCNAME.cache.$(H "$@" "$ALL_RELATIONS")" \
           s rn ts rc td
@@ -3803,6 +3831,31 @@ display_commands_help() {
     fi
 }
 
+get_docker_charm_action() {
+    local services service charm relation_name target_service relation_config \
+          target_charm
+    services=($(get_compose_yml_content | yq -r 'keys().[]' 2>/dev/null)) || return 1
+    NO_CONSTRAINT_CHECK=1 get_all_relations "${services[@]}" >/dev/null || return 1
+    services=($(get_all_services)) || return 1
+    for service in "${services[@]}"; do
+        printf "%s:\n" "$service"
+        charm=$(get_service_charm "$service") || return 1
+        for action in $(charm.ls_direct_actions "$charm"); do
+            printf "  %s:\n" "$action"
+            printf "    type: %s\n" "direct"
+        done
+        while read-0 relation_name target_service _relation_config _tech_dep; do
+            target_charm=$(get_service_charm "$target_service") || return 1
+            for action in $(charm.ls_relation_actions "$target_charm" "$relation_name"); do
+                printf "  %s:\n" "$action"
+                printf "    type: %s\n" "indirect"
+                printf "    inherited: %s\n" "$target_charm"
+            done
+        done < <(get_service_relations "$service")
+    done
+}
+export -f get_docker_charm_action
+
 get_docker_charm_action_help() {
     local services service charm relation_name target_service relation_config \
           target_charm
@@ -3841,6 +3894,8 @@ display_help() {
     echo "                              (ignoring any other options)"
     echo "  --get-project-name          Display project name and quit"
     echo "                              (ignoring any other options)"
+    echo "  --get-available-actions     Display all available actions and quit"
+    echo "                              (ignoring any other options)"
     echo "  -v, --verbose               Be more verbose"
     echo "  -q, --quiet                 Be quiet"
     echo "  -d, --debug                 Print full debugging information (sets also verbose)"
@@ -4198,6 +4253,10 @@ while read-0 arg; do
                     echo "$project"
                     exit 0
                     ;;
+                --get-available-actions)
+                    get_docker_charm_action
+                    exit $?
+                    ;;
                 --dry-compose-run)
                     export DRY_COMPOSE_RUN=true
                     ;;