Should work.

Dockerfile

@@ -3,33 +3,30 @@ MAINTAINER chbmb
 
 # set paths
 ENV WWW_ROOT="/config/www"
-ENV COPS_PATH="${WWW_ROOT}/cops"
-
-# install build-dependencies
-RUN \
- apk add --no-cache --virtual=build-dependencies \
-	#####
-
-# uninstall build-dependencies
- apk del --purge \
-	build-dependencies && \
+ENV COPS_PATH="${WWW_ROOT}/books"
 
+# install cops
+ mkdir /config/www/books/
+ wget -P /tmp https://github.com/seblucas/cops/releases/download/1.0.0/cops-1.0.0.zip
+ unzip -d /config/www/books/ cops-1.0.0.zip 
+ 
 # cleanup
  rm -rfv /tmp/*
  
 # install runtime packages
 RUN \
  apk add --no-cache \
-	php5-sqlite \
 	php5-gd \
 	php5-intl \
+	php5-pdo_sqlite \
+	php5-sqlite3 \
+	sqlite \
 	
 # add local files
 COPY root/ /
 
 # ports and volumes
-VOLUME /config /data
+VOLUME /config /books
 EXPOSE 80 443
 
-# set nextcloud version
-ENV COPS_VER="1.0.0"
+

root/defaults/config-local.php

@@ -1,30 +0,0 @@
-<?php
-  if (!isset($config))
-        $config = array();
-  
-	/*
-	* The directory containing calibre's metadata.db file, with sub-directories
-	* containing all the formats.
-	* BEWARE : it has to end with a /
-	*/
-	$config['calibre_directory'] = '/books/';
-    
-	/*
-	* Catalog's title
-	*/
-	$config['cops_title_default'] = "COPS";
-    
-	/*
-	* use URL rewriting for downloading of ebook in HTML catalog
-	* See README for more information
-	*  1 : enable
-	*  0 : disable
-	*/
-    	$config['cops_use_url_rewriting'] = "0";
-	
-	$config['cops_mail_configuration'] = array( 	"smtp.host"     => "smtp.gmail.com",
-							"smtp.username" => "",
-							"smtp.password" => "",
-							"smtp.secure"   => "ssl",
-							"address.from"  => "COPS"
-); 

root/www/books/config-local.php

@@ -0,0 +1,49 @@
+<?php
+    if (!isset($config))
+        $config = array();
+  
+    /*
+     * The directory containing calibre's metadata.db file, with sub-directories
+     * containing all the formats.
+     * BEWARE : it has to end with a /
+     */
+    $config['calibre_directory'] = '/books/';
+	
+	$config['calibre_internal_directory'] = '/cops/'; 
+    
+    /*
+     * Catalog's title
+     */
+    $config['cops_title_default'] = "COPS";
+    
+    /*
+     * use URL rewriting for downloading of ebook in HTML catalog
+     * See README for more information
+     *  1 : enable
+     *  0 : disable
+     */
+    $config['cops_use_url_rewriting'] = "0";
+
+	/*
+     * Which header to use when downloading books outside the web directory
+     * Possible values are :
+     *   X-Accel-Redirect   : For Nginx
+     *   X-Sendfile         : For Lightttpd or Apache (with mod_xsendfile)
+     *   No value (default) : Let PHP handle the download
+     */ 
+	 
+	 $config['cops_x_accel_redirect'] = "X-Accel-Redirect";
+	
+    /*
+     * use URL rewriting for downloading of ebook in HTML catalog
+     * See README for more information
+     *  1 : enable
+     *  0 : disable
+     */
+	
+	$config['cops_mail_configuration'] = array( "smtp.host"     => "",
+												"smtp.username" => "",
+												"smtp.password" => "",
+												"smtp.secure"   => "ssl",
+												"address.from"  => "COPS"
+);