custom_script: make 'args' parameter as list

'args' parameter can be pointed as string or as list

  args: "-v -h"
or
  args:
    - "-v"
    - "-h"

Signed-off-by: Dmytro Semenets <[email protected]>

docs/user-reference.rst

@@ -702,6 +702,9 @@ script as parameter
     type: custom_script        # Should be 'custom_script'
     work_dir : "script_workdir"
     script: "path/to/script/custom_script.py"
+    args:
+      - "argument1"
+      - "argument2"
     config:
       items:
         "rootfs": "images/spider/rootfs.tar.bz2"
@@ -732,7 +735,8 @@ Mandatory options:
 
 Optional parameters:
 
-* :code:`args` - additional arguments should be passed to :code:`script`
+* :code:`args` - additional arguments should be passed to :code:`script`. Can be passed as
+  string or list
 
 * :code:`additional_deps` - list of additional dependencies. This is
   basically :code:`target_images` produced by other components. You

moulin/builders/custom_script.py

@@ -10,6 +10,7 @@
 import os.path
 from typing import List
 from moulin.yaml_wrapper import YamlValue
+from moulin.yaml_helpers import YAMLProcessingError
 from moulin import ninja_syntax
 
 
@@ -86,11 +87,16 @@ def gen_build(self):
 
         self.generator.build(f"conf-{self.name}", "phony", local_conf_target)
         self.generator.newline()
-
+        args_node = self.conf.get("args", "")
+        try:
+            args = args_node.as_str
+        except YAMLProcessingError:
+            args_vals = [x.as_str for x in args_node]
+            args = " ".join([val for val in args_vals])
         self.generator.build(targets, "cs_build", deps, variables=dict(
             common_variables,
             config_file=local_conf_file,
-            args=self.conf.get("args", "").as_str))
+            args=args))
         self.generator.newline()
 
         return targets