Finished intitial script for rendering templates

scripts/render_templates.py

@@ -1,6 +1,7 @@
 import os
 import jinja2
 import argparse
+import traceback
 
 def render_template(template_file: str, 
                     out_path: str,
@@ -15,16 +16,26 @@ def render_template(template_file: str,
         save.write(template.render(**kwargs))
 
 
+def load_template_vars_file(var_file_path: str) -> dict:
+    result = {}
+    with open(var_file_path) as reader:
+        for line in reader:
+            key, value = line.split('=', 1)
+            result[key] = value
+
+    return result
+
+
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(prog='render_templates.py',
                                      description='A script to render the docker jinja templates.',
                                      add_help=True)
     parser.add_argument('template_path',
-                        help='The path to the template to render.')
+                        help='The path to the template(s) to render (Can be either a directory or a file).')
     parser.add_argument('var_file_path',
                         help='The path to the file containing the variables to use for rendering the tempalte(s).')
     parser.add_argument('out_path',
-                        help='The path to write the rendered template.')
+                        help='The path to write the rendered template (MUST be a directory).')
     parser.add_argument('-k', 
                         '--kwargs',
                         required=False,
@@ -38,6 +49,7 @@ if __name__ == '__main__':
 
     args = parser.parse_args()
 
+    # make sure we have a template file and a variable file.
     if not os.path.exists(args.template_path):
         print(f'The given template path {args.template_path} does not exist.')
         exit(1)
@@ -46,3 +58,42 @@ if __name__ == '__main__':
         print(f'The given template path {args.var_file_path} does not exist.')
         exit(1)
     
+    run_on_dir = False
+    # if the template path is a directory, make sure output path exists
+    if os.path.isdir(args.template_path):
+        run_on_dir = True
+        if not os.path.exists(args.out_path):
+            os.makedirs(args.out_path)
+        else:
+            print('The output path must be a directory since the template path is.')
+            exit(1)
+
+        args.template_path = [os.path.join(args.template_path, p) 
+                              for p in filter(lambda x: x.ends_with('.tmpl'),
+                                              os.listdir(args.template_path))]
+    # if the tempalte path is a file
+    else:
+        # wrap it in a list
+        args.template_path = [args.template_path]
+
+    # load the variables from the variable file
+    kwargs = load_template_vars_file(args.var_file_path)
+    args.kwargs = {a.split('=')[0]: a.split('=')[1] for a in args.kwargs.split(',')} if args.kwargs else {}
+    for k in kwargs:
+        # The assumption made here is that anything passed on the commandline should be prioritized
+        # over values that appear in the template variables file.
+        if k not in args.kwargs:
+            args.kwargs[k] = kwargs[k]
+
+    for template in args.template_path:
+        out_file_name = os.path.join(args.out_path,
+                                     os.path.split(template.remove('.tmpl')))
+        # if the output exists and we aren't overwritting files, then move on.
+        if os.path.exists(out_file_name) and not args.overwrite:
+            continue
+
+        try:
+            render_template(template, out_file_name, **args.kwargs)
+        except Exception as ex:
+            print(f'Failed to render template "{template}":')
+            print(f'Error: {str(ex)}\n{traceback.format_exec()}')