[pitboss] phase 12: Track B — Python harness emitter shapes

tests/dynamic_fixtures/python/flask/benign.py

@@ -0,0 +1,24 @@
+"""Phase 12 — Flask route, benign."""
+import re
+import subprocess
+
+from flask import Flask, request
+
+app = Flask(__name__)
+
+_VALID_HOST = re.compile(r"^[A-Za-z0-9.-]{1,253}$")
+
+
+@app.route("/ping", methods=["GET"])
+def ping():
+    host = request.args.get("host", "")
+    if not _VALID_HOST.fullmatch(host):
+        return "invalid host"
+    result = subprocess.run(
+        ["ping", "-c", "1", host],
+        shell=False,
+        capture_output=True,
+        text=True,
+        timeout=5,
+    )
+    return result.stdout + result.stderr