add kindlegen, update node, more robust Dockerfile

Dockerfile

@@ -1,19 +1,29 @@
-FROM node:16
+FROM node:20
 
 # Create app directory
 WORKDIR /usr/src/app
 
+# Copy app files (see .dockerignore)
+COPY . ./
+
 # Install app dependencies
-# A wildcard is used to ensure both package.json AND package-lock.json are copied
-# where available (npm@5+)
-COPY package*.json ./
+RUN npm install --omit=dev
 
-# Download, and prepare the kepubify binary
-RUN wget https://github.com/pgaskin/kepubify/releases/download/v4.0.4/kepubify-linux-64bit
-RUN mv kepubify-linux-64bit /usr/local/bin/kepubify
-RUN chmod +x /usr/local/bin/kepubify
+# Download and install kepubify
+RUN wget https://github.com/pgaskin/kepubify/releases/download/v4.0.4/kepubify-linux-64bit && \
+    mv kepubify-linux-64bit /usr/local/bin/kepubify && \
+    chmod +x /usr/local/bin/kepubify
 
-COPY . .
+# Download and install kindlegen
+RUN wget https://archive.org/download/kindlegen2.9/kindlegen_linux_2.6_i386_v2_9.tar.gz && \
+    mkdir kindlegen && \
+    tar xvf kindlegen_linux_2.6_i386_v2_9.tar.gz --directory kindlegen && \
+    cp kindlegen/kindlegen /usr/local/bin/kindlegen && \
+    chmod +x /usr/local/bin/kindlegen && \
+    rm -rf kindlegen
+
+# Create uploads directory if it doesn't exist
+RUN mkdir uploads
 
 EXPOSE 3001
-CMD [ "node", "index" ]
+CMD [ "npm", "start" ]