calibre-web: init at 0.6.11

There are two patches applied to 'calibre-web' in order to make it more
NixOS friendly:

  - default-logger.patch switches default log output to /dev/stdout, as
    otherwise calibre-web tries to open a file relative to its location,
    which it can't do as the store is read-only. It's not possible to
    pass log file location via command line flags.

  - run-migrations.patch adds an env var __RUN_MIGRATIONS_AND_EXIT that,
    when set, instructs calibre-web to run DB migrations and exit. As
    almost all config parameters are configured via UI in sqlite3 DB,
    this patch allows the DB to be pre-created so it can be updated by
    systemd pre-start script later.  Thus, allowing calibre-web to be
    configured declaratively.

pkgs/servers/calibre-web/default.nix

@@ -0,0 +1,69 @@
+{ lib
+, fetchFromGitHub
+, python3
+, python3Packages
+}:
+
+python3.pkgs.buildPythonApplication rec {
+  pname = "calibre-web";
+  version = "0.6.11";
+
+  src = fetchFromGitHub {
+    owner = "janeczku";
+    repo = "calibre-web";
+    rev = version;
+    sha256 = "10sjllhhcamswpa1wlim4mbm2zl4g804bwly5p4nmklg7n1v226g";
+  };
+
+  prePatch = ''
+    substituteInPlace setup.cfg \
+        --replace "requests>=2.11.1,<2.25.0" "requests>=2.11.1,<2.26.0" \
+        --replace "cps = calibreweb:main" "calibre-web = calibreweb:main"
+  '';
+
+  patches = [
+    # default-logger.patch switches default logger to /dev/stdout. Otherwise calibre-web tries to open a file relative
+    # to its location, which can't be done as the store is read-only. Log file location can later be configured using UI
+    # if needed.
+    ./default-logger.patch
+    # DB migrations adds an env var __RUN_MIGRATIONS_ANDEXIT that, when set, instructs calibre-web to run DB migrations
+    # and exit. This is gonna be used to configure calibre-web declaratively, as most of its configuration parameters
+    # are stored in the DB.
+    ./db-migrations.patch
+  ];
+
+  # calibre-web doesn't follow setuptools directory structure. The following is taken from the script
+  # that calibre-web's maintainer is using to package it:
+  # https://github.com/OzzieIsaacs/calibre-web-test/blob/master/build/make_release.py
+  postPatch = ''
+    mkdir -p src/calibreweb
+    mv cps.py src/calibreweb/__init__.py
+    mv cps src/calibreweb
+  '';
+
+  # Upstream repo doesn't provide any tests.
+  doCheck = false;
+
+  propagatedBuildInputs = with python3Packages; [
+    backports_abc
+    flask-babel
+    flask_login
+    flask_principal
+    iso-639
+    pypdf2
+    requests
+    singledispatch
+    sqlalchemy
+    tornado
+    unidecode
+    Wand
+  ];
+
+  meta = with lib; {
+    description = "Web app for browsing, reading and downloading eBooks stored in a Calibre database";
+    maintainers = with maintainers; [ pborzenkov ];
+    homepage = "https://github.com/janeczku/calibre-web";
+    license = licenses.gpl3Plus;
+    platforms = platforms.all;
+  };
+}