use readline in logger

app.py

@@ -11,14 +11,14 @@ def run():
     import sys
 
     with open("out-file.txt", "w") as f:
-        proc = subprocess.Popen(
+        process = subprocess.Popen(
             [f"{sys.executable}", "prometheus_pipeline.py"],
             stdout=subprocess.PIPE,
         )
 
     content = ""
 
-    for line in proc.stdout:
+    for line in iter(process.stdout.readline, ""):
         content = content.split("\n")
         content.append(line.decode("utf-8"))
         content = content[-10:]