[BUG] `unknown instruction: apk` build error

[bilogic]

Is there an existing issue for this?

• I have searched the existing issues

Current Behavior

Error when building, see logs

Expected Behavior

No response

Steps To Reproduce

Run the command from README.md, docker build --no-cache --pull -t lscr.io/linuxserver/bookstack:latest . to see the error

Environment

- OS: Ubuntu 22.04
- How docker service was installed: distro's packagemanager

CPU architecture

x86-64

Docker creation

docker build   --no-cache   --pull   -t lscr.io/linuxserver/bookstack:latest .

Container logs

$ sudo docker build   --no-cache   --pull   -t lscr.io/linuxserver/bookstack:latest .
[+] Building 0.9s (3/3) FINISHED                                                                                                                                                docker:default
 => [internal] load build definition from Dockerfile                                                                                                                                      0.0s
 => => transferring dockerfile: 2.52kB                                                                                                                                                    0.0s
 => resolve image config for docker-image://docker.io/docker/dockerfile:1                                                                                                                 0.8s
 => CACHED docker-image://docker.io/docker/dockerfile:1@sha256:9857836c9ee4268391bb5b09f9f157f3c91bb15821bb77969642813b0d00518d                                                           0.0s
Dockerfile:16
--------------------
  15 |         echo "**** install runtime packages ****" &&
  16 | >>>     apk add --no-cache \
  17 | >>>         fontconfig \
  18 | >>>         mariadb-client \
  19 | >>>         memcached \
  20 | >>>         php83-dom \
  21 | >>>         php83-exif \
  22 | >>>         php83-gd \
  23 | >>>         php83-ldap \
  24 | >>>         php83-mysqlnd \
  25 | >>>         php83-opcache \
  26 | >>>         php83-pdo_mysql \
  27 | >>>         php83-pecl-memcached \
  28 | >>>         php83-tokenizer \
  29 | >>>         qt5-qtbase \
  30 | >>>         ttf-freefont &&
  31 |         echo "**** configure php-fpm to pass env vars ****" &&
--------------------
ERROR: failed to solve: dockerfile parse error on line 16: unknown instruction: apk (did you mean add?)

[github-actions]

Thanks for opening your first issue here! Be sure to follow the relevant issue templates, or risk having this issue marked as invalid.

[bilogic]

My bad, works when I cloned the repo as a whole. Initially, I created only Dockerfile in my folder