block/bridge: refactor into general bridge block subsystem

app/terraform/block/bridge_github.py

@@ -0,0 +1,25 @@
+from flask import current_app
+from github import Github
+
+from app.terraform.block.bridge_reachability import BlockBridgeReachabilityAutomation
+
+
+class BlockBridgeGitHubAutomation(BlockBridgeReachabilityAutomation):
+    """
+    Automation task to import bridge reachability results from GitHub.
+    """
+
+    short_name = "block_bridge_github"
+    description = "Import bridge reachability results from GitHub"
+    frequency = 30
+
+    def fetch(self) -> None:
+        github = Github(current_app.config['GITHUB_API_KEY'])
+        repo = github.get_repo(current_app.config['GITHUB_BRIDGE_REPO'])
+        for vantage_point in current_app.config['GITHUB_BRIDGE_VANTAGE_POINTS']:
+            contents = repo.get_contents(f"recentResult_{vantage_point}")
+            if isinstance(contents, list):
+                raise RuntimeError(
+                        f"Expected a file at recentResult_{vantage_point}"
+                        " but got a directory.")
+            self._lines = contents.decoded_content.decode('utf-8').splitlines()