Implemented actually generating docker-compos.yml, plus some error handling.

yarrbox.py

@@ -49,6 +49,12 @@ def ask_config_opt(config, key):
 
     config[key] = val
 
+def apply_template_settings(tmplt, settings):
+    cur = tmplt
+    for k, v in settings.items():
+        cur = cur.replace('${' + k + '}', v)
+    return cur
+
 USAGE_STR = 'usage: yarrbox.py <init|edit|generate>'
 
 def main():
@@ -65,15 +71,23 @@ def main():
             print('')
 
         # Write it to file
-        with open('config.json', 'w') as f:
-            f.write(json.dumps(cfg))
+        try:
+            with open('config.json', 'w') as f:
+                f.write(json.dumps(cfg))
+        except e:
+            print('error writing config, do we have write perms?', e)
+            return
 
     elif command == 'edit':
         print('Leave options blank to leave unchanged!\n')
         # Read the file.
         cfg = None
-        with open('config.json', 'r') as f:
-            cfg = json.loads(f.read())
+        try:
+            with open('config.json', 'r') as f:
+                cfg = json.loads(f.read())
+        except e:
+            print('error loading config, is it missing or corrupt?', e)
+            return
 
         # Go through all the properties again and reread them.
         for k in PROPS:
@@ -81,9 +95,38 @@ def main():
             print('')
 
         # Write it back.
-        with open('config.json', 'w') as f:
-            f.write(json.dumps(cfg))
-
+        try:
+            with open('config.json', 'w') as f:
+                f.write(json.dumps(cfg))
+        except e:
+            print('error writing config, do we have write perms?', e)
+            return
+
+    elif command == 'generate':
+        # Load the config.
+        cfg = None
+        try:
+            with open('config.json', 'r') as f:
+                cfg = json.loads(f.read())
+        except e:
+            print('error loading config, is it missing or corrupt?', e)
+            return
+
+        tmplt = None
+        try:
+            with open('compose-template.yml', 'r') as f:
+                tmplt = f.read()
+        except e:
+            print('error reading template:', e)
+            return
+
+        gen = apply_template_settings(tmplt, cfg)
+        try:
+            with open('docker-compose.yml', 'w') as f:
+                f.write(gen)
+        except e:
+            print('error writing generated file, do we have write perms?', e)
+            return
     else:
         print(USAGE_STR)