Replace ruby script with python (issue ros2#158)

Earthfile

@@ -33,7 +33,7 @@ setup:
   RUN echo "deb [arch=$(dpkg --print-architecture) signed-by=/usr/share/keyrings/ros-archive-keyring.gpg] http://packages.ros.org/ros2/ubuntu $(lsb_release -cs) main" | tee /etc/apt/sources.list.d/ros2.list > /dev/null
 
   # Install repos file generator script requirements.
-  RUN apt-get install -y python3-rosinstall-generator ruby
+  RUN apt-get install -y python3-rosinstall-generator
 
 repos-file:
   FROM +setup
@@ -48,7 +48,7 @@ repos-file:
                  --outfile ros2.repos \
                  --packages spaceros-pkgs.txt \
                  --excluded-packages excluded-pkgs.txt
-  RUN --no-cache ruby scripts/merge-repos.rb
+  RUN --no-cache python3 scripts/merge-repos.py
 
   # Save the generated .repos file
   SAVE ARTIFACT ros2.repos AS LOCAL ros2.repos

scripts/merge-repos.py

@@ -0,0 +1,22 @@
+#!/usr/bin/env python3
+
+import yaml
+
+# Load YAML repos files
+with open('ros2.repos', 'r') as ros2_file:
+    ros2 = yaml.safe_load(ros2_file)
+
+with open('spaceros.repos', 'r') as spaceros_file:
+    spaceros = yaml.safe_load(spaceros_file)
+
+# Merge repos
+for repo, data in spaceros['repositories'].items():
+    ros2['repositories'][repo] = data
+
+# Sort repositories and create a new ordered dictionary
+sorted_repositories = {repo: ros2['repositories'][repo] for repo in sorted(ros2['repositories'].keys())}
+ros2['repositories'] = sorted_repositories
+
+# Write the updated YAML back to file
+with open('ros2.repos', 'w') as ros2_file:
+    yaml.dump(ros2, ros2_file, default_flow_style=False, explicit_start=True)