Add error message when frontend does not start

sist2-admin/sist2_admin/util.py

@@ -0,0 +1,41 @@
+from glob import glob
+import os
+from config import DATA_FOLDER
+
+
+def get_old_index_files(name):
+    files = glob(os.path.join(DATA_FOLDER, f"scan-{name.replace('/', '_')}-*.sist2"))
+    files = list(sorted(files, key=lambda f: os.stat(f).st_mtime))
+    files = files[-1:]
+
+    return files
+
+
+def tail_sync(filename, lines=1, _buffer=4098):
+    with open(filename) as f:
+        lines_found = []
+
+        block_counter = -1
+
+        while len(lines_found) < lines:
+            try:
+                f.seek(block_counter * _buffer, os.SEEK_END)
+            except IOError:
+                f.seek(0)
+                lines_found = f.readlines()
+                break
+
+            lines_found = f.readlines()
+
+            block_counter -= 1
+
+        return lines_found[-lines:]
+
+
+def pid_is_running(pid):
+    try:
+        os.kill(pid, 0)
+    except OSError:
+        return False
+
+    return True