Add a function to check the configuration for errors. (#1919)

This can be used as a sanity check before a deployment:

  chanzuckerberg/single-cell#63

server/eb/check_config.py

@@ -0,0 +1,39 @@
+import sys
+import argparse
+import yaml
+
+from server.common.config.app_config import AppConfig
+
+
+def main():
+    parser = argparse.ArgumentParser("A script to check hosted configuration files")
+    parser.add_argument("config_file", help="the configuration file")
+    parser.add_argument(
+        "-s",
+        "--show",
+        default=False,
+        action="store_true",
+        help="print the configuration. NOTE: this may print secret values to stdout",
+    )
+
+    args = parser.parse_args()
+
+    app_config = AppConfig()
+    app_config.update_from_config_file(args.config_file)
+    try:
+        app_config.complete_config()
+    except Exception as e:
+        print(f"Error: {str(e)}")
+        print("FAIL:", args.config_file)
+        sys.exit(1)
+
+    if args.show:
+        yaml_config = app_config.config_to_dict()
+        yaml.dump(yaml_config, sys.stdout)
+
+    print("PASS:", args.config_file)
+    sys.exit(0)
+
+
+if __name__ == "__main__":
+    main()