update agent

agent/app/core/installer.py

@@ -1,8 +1,9 @@
 from __future__ import annotations
 
+import time
 from pathlib import Path
 
-from app.core.command_runner import CommandRunner
+from app.core.command_runner import CommandError, CommandRunner
 
 
 APT_DPKG_OPTIONS = [
@@ -101,3 +102,42 @@ class DebInstaller:
             return True
         except Exception:
             return False
+
+
+class AptInstaller(DebInstaller):
+    def update_package_index(self) -> None:
+        self.command_runner.run(
+            ["apt-get", "update"],
+            timeout=600,
+            env=APT_NONINTERACTIVE_ENV,
+        )
+
+    def install_package(self, package_name: str) -> None:
+        self.command_runner.run(
+            [
+                "apt-get",
+                *APT_DPKG_OPTIONS,
+                "install",
+                "--yes",
+                package_name,
+            ],
+            timeout=1200,
+            env=APT_NONINTERACTIVE_ENV,
+        )
+
+    def wait_for_postgresql(
+        self,
+        attempts: int = 6,
+        delay_seconds: float = 2.0,
+    ) -> None:
+        last_error: CommandError | None = None
+        for attempt in range(1, attempts + 1):
+            try:
+                self.command_runner.run(["pg_isready", "--timeout=5"], timeout=10)
+                return
+            except CommandError as error:
+                last_error = error
+                if attempt < attempts:
+                    time.sleep(delay_seconds)
+
+        raise RuntimeError("PostgreSQL did not become ready after installation") from last_error