add tests

tests/filesystems/test_overlay.py

@@ -3,11 +3,11 @@
 
 
 def test_overlay_filesystem_docker_container(target_linux_docker: Target) -> None:
-    mount_path = list(target_linux_docker.fs.path("/var/lib/docker/image/overlay2/layerdb/mounts/").iterdir())[0]
+    mount_path = target_linux_docker.fs.path("/var/lib/docker/image/overlay2/layerdb/mounts/f988f88e221d97930a665712cf16ab520f7e2c5af395660c145df93aebedf071")  # noqa: E501
     fs = Overlay2Filesystem(mount_path)
 
     assert fs.__type__ == "overlay2"
-    assert len(fs.layers) == 4
+    assert len(fs.layers) == 9
 
     assert sorted([str(p) for p in fs.path("/").iterdir()]) == sorted(
         [
@@ -29,13 +29,14 @@ def test_overlay_filesystem_docker_container(target_linux_docker: Target) -> Non
             "/usr",
             "/srv",
             "/.dockerenv",
+            "/container",
         ]
     )
 
-    assert [str(p) for p in fs.path("/root").iterdir()] == [
-        "/root/secret.txt",
-        "/root/file.txt",
+    assert sorted([str(p) for p in fs.path("/root").iterdir()]) == [
         "/root/.ash_history",
+        "/root/file.txt",
+        "/root/secret.txt",
     ]
 
     assert fs.path("/root/secret.txt").open().read() == b"this is a secret!\n"
@@ -47,3 +48,18 @@ def test_overlay_filesystem_docker_container(target_linux_docker: Target) -> Non
     assert fs.path("/bin/sh").readlink() == fs.path("/bin/busybox")
     assert fs.path("/etc/ssl/cert.pem").resolve() == fs.path("/etc/ssl/certs/ca-certificates.crt")
     assert fs.path("/usr/lib/libcrypto.so.3").resolve() == fs.path("/lib/libcrypto.so.3")
+
+    # test if standard mounts were correctly added
+    assert fs.path("/etc/hostname").exists()
+    assert fs.path("/etc/hostname").is_file()
+    assert fs.path("/etc/hostname").read_text() == "f988f88e221d\n"
+    assert fs.path("/etc/hosts").exists()
+    assert fs.path("/etc/resolv.conf").exists()
+
+    # test if custom mounts were correctly added
+    assert fs.path("/container/file.txt").exists()
+    assert fs.path("/container/file.txt").is_file()
+    assert fs.path("/container/folder").exists()
+    assert fs.path("/container/folder").is_dir()
+    assert fs.path("/container/folder/some-file.txt").exists()
+    assert fs.path("/container/folder/some-file.txt").is_file()