fix(furtka): chmod 755 on version dir + heredoc furtka.json

Two install-path bugs surfaced by SSHing into the hot-fixed test VM:

1. mktemp creates the staging dir with mode 700 by default; the rename
   to /opt/furtka/versions/<ver>/ preserved it, and Caddy (running as
   the unprivileged `caddy` user) got 403 Forbidden because it couldn't
   traverse the version dir. Now the install + self-update both
   `chmod 755` after the rename.

2. _furtka_json_cmd was a silent no-op on the 43a39a4 VM — the
   base64-encoded body + sed substitution approach layered two sets of
   quotes through archinstall's custom_commands eval, and the sed
   step either never ran or didn't match. Replaced with a plain
   heredoc that interpolates $(date -Iseconds) and $(cat VERSION) at
   chroot runtime. Result lands /var/lib/furtka/furtka.json reliably,
   which is what the landing page's hostname chip and the settings
   page's install-date field depend on.

Both issues confirmed fixed by applying them manually on the VM
(chmod 755 /opt/furtka/versions/26.0-alpha + writing furtka.json by
hand): landing page, /apps, /settings, /furtka.json all now 200 with
correct content.

Tests updated (the chmod 755 gets asserted; the old base64+sed test
gets replaced with a heredoc-shape check; the updater test asserts
0o755 mode on the finished version dir).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

furtka/updater.py

@@ -319,6 +319,9 @@ def apply_update(tarball: Path, version: str) -> None:
     if target.exists():
         shutil.rmtree(target)
     staging.rename(target)
+    # mktemp-style 700 default on the staging dir carries through the
+    # rename; Caddy (non-root) needs 755 to traverse /opt/furtka/current/.
+    target.chmod(0o755)
 
     write_state("swapping", latest=version)
     previous = None

tests/test_updater.py

@@ -150,6 +150,10 @@ def test_apply_update_happy_path(tmp_path, updater, monkeypatch):
 
     assert current.resolve() == (versions / "26.1-alpha").resolve()
     assert (versions / "26.1-alpha" / "VERSION").read_text().strip() == "26.1-alpha"
+    # Version dir is 755 so Caddy can traverse it — the staging dir came
+    # from mktemp-ish extractall which defaults to 700, and carries through
+    # the rename unless we explicitly chmod.
+    assert (versions / "26.1-alpha").stat().st_mode & 0o777 == 0o755
     # P1-2: Caddyfile was copied into /etc/caddy/ from the new version.
     assert updater._CADDYFILE_LIVE.read_text() == "# new caddy config\n"
     state = updater.read_state()

tests/test_webinstaller_assets.py

@@ -78,9 +78,23 @@ def test_resource_manager_extracts_to_versioned_slot(install_cmds):
     # An empty VERSION file must abort the install instead of silently
     # moving the staging dir into versions/ as a subdir.
     assert '[ -n "$ver" ]' in extract_cmd
+    # Version dir must be 755 so Caddy (non-root) can traverse it.
+    assert 'chmod 755 "/opt/furtka/versions/$ver"' in extract_cmd
     assert 'ln -sfn "/opt/furtka/versions/$ver" /opt/furtka/current' in extract_cmd
 
 
+def test_furtka_json_cmd_uses_heredoc_and_interpolates_hostname(install_cmds):
+    # Regression: the previous base64+sed version of this command was a
+    # silent no-op on some installs due to archinstall-side quoting; the
+    # heredoc version is the one that reliably writes furtka.json.
+    cmd = next((c for c in install_cmds if "/var/lib/furtka/furtka.json" in c), None)
+    assert cmd is not None
+    assert "cat > /var/lib/furtka/furtka.json <<EOF" in cmd
+    assert '"hostname": "testhost"' in cmd
+    assert "date -Iseconds" in cmd
+    assert "/opt/furtka/current/VERSION" in cmd
+
+
 def test_resource_manager_systemctl_links_every_unit(install_cmds):
     link_cmd = next((c for c in install_cmds if c.startswith("systemctl link ")), None)
     assert link_cmd is not None, "no systemctl link command"
@@ -95,23 +109,6 @@ def test_resource_manager_enables_all_units(install_cmds):
         assert unit in enable_cmd
 
 
-def test_furtka_json_written_with_hostname(install_cmds):
-    furtka_json = next(
-        (c for c in install_cmds if "/var/lib/furtka/furtka.json" in c and "mkdir" in c),
-        None,
-    )
-    assert furtka_json is not None
-    # The base64-encoded JSON body should contain the hostname we passed in.
-    content = _extract_written_content(furtka_json, "/var/lib/furtka/furtka.json")
-    assert '"hostname": "testhost"' in content
-    # install_date + version placeholders — the sed below substitutes them at
-    # install time against /opt/furtka/current/VERSION + `date -Iseconds`.
-    assert "__INSTALL_DATE__" in content
-    assert "__VERSION__" in content
-    assert "date -Iseconds" in furtka_json
-    assert "/opt/furtka/current/VERSION" in furtka_json
-
-
 def test_wrapper_script_points_at_current_symlink():
     assert "PYTHONPATH=/opt/furtka/current" in app._FURTKA_WRAPPER_SH
 

webinstaller/app.py

@@ -263,6 +263,11 @@ def _resource_manager_commands():
         # as a subdir and the symlink target would be invalid.
         '[ -n "$ver" ] || { echo "empty VERSION in payload" >&2; exit 1; } && '
         'mv "$staging" "/opt/furtka/versions/$ver" && '
+        # mktemp -d creates the staging dir with mode 700; that survives the
+        # mv and leaves Caddy (which runs as the `caddy` user, not root)
+        # unable to traverse /opt/furtka/current/ when it tries to serve
+        # the landing page. Open up to 755 so file_server can read.
+        'chmod 755 "/opt/furtka/versions/$ver" && '
         'ln -sfn "/opt/furtka/versions/$ver" /opt/furtka/current'
     )
     systemctl_link = "systemctl link " + " ".join(
@@ -284,24 +289,23 @@ def _furtka_json_cmd(hostname):
     at runtime and renders the hostname chip from it. install_date + version
     ride along so the settings page can display them without hitting the
     status timer's refresh cycle.
+
+    Heredoc rather than base64 + sed — the previous version had two layers
+    of quoting that archinstall's custom_commands shell-eval path parsed
+    inconsistently, leaving this command as a silent no-op on some installs.
+    The heredoc evaluates `$(date ...)` and `$(cat VERSION)` at chroot
+    runtime and sidesteps the quoting hazard entirely. Hostname has already
+    been validated by validate_step1.
     """
-    # Python-side JSON assembly keeps the shell command free of quote-escape
-    # hazards. Hostname is validated up-front in validate_step1 so it's safe
-    # to interpolate.
-    body = json.dumps(
-        {
-            "hostname": hostname,
-            "install_date": "__INSTALL_DATE__",
-            "version": "__VERSION__",
-        },
-        indent=2,
-    )
     return (
         "mkdir -p /var/lib/furtka && "
-        + _write_file_cmd("/var/lib/furtka/furtka.json", body)
-        + ' && sed -i "s/__INSTALL_DATE__/$(date -Iseconds)/;'
-        's|__VERSION__|$(cat /opt/furtka/current/VERSION 2>/dev/null || echo dev)|"'
-        " /var/lib/furtka/furtka.json"
+        "cat > /var/lib/furtka/furtka.json <<EOF\n"
+        "{\n"
+        f'  "hostname": "{hostname}",\n'
+        '  "install_date": "$(date -Iseconds)",\n'
+        '  "version": "$(cat /opt/furtka/current/VERSION 2>/dev/null || echo dev)"\n'
+        "}\n"
+        "EOF"
     )