change lts to v12

Dockerfile

@@ -1,7 +1,10 @@
-FROM node:lts-alpine
+FROM node:12
 WORKDIR /data
-RUN echo "http://dl-4.alpinelinux.org/alpine/edge/main" >> /etc/apk/repositories && \
+COPY ./ffmpeg.tgz /
-  echo "http://dl-4.alpinelinux.org/alpine/edge/community" >> /etc/apk/repositories && \
+RUN apt-get update && \
-  echo "http://dl-4.alpinelinux.org/alpine/edge/testing" >> /etc/apk/repositories && \
+  apt-get install -y unoconv curl imagemagick graphicsmagick curl wget python3 python3-pip qpdf poppler-utils git curl wget && \
-  apk upgrade && \
+  apt-get clean && \
-  apk add --no-cache build-base py3-unoconv imagemagick graphicsmagick curl wget git python3-dev jpeg-dev zlib-dev qpdf poppler-utils ffmpeg python bash
+  mkdir -p /usr/local/bin && \
+  tar zxvf /ffmpeg.tgz -C /usr/local/bin && \
+  rm /ffmpeg.tgz && \
+  rm -rf /var/lib/apt/lists