Hola, estoy tratando de construir un contenedor usando nginx, sin embargo, no puedo avanzar después de estos pasos:

 Building nginx Step 1/17 : FROM nginx:alpine ---> 377c0837328f Step 2/17 : LABEL maintainer="Mahmoud Zalt mahmoud@zalt.me" ---> Running in 8d53a074e85a Removing intermediate container 8d53a074e85a ---> 6053f271c802 Step 3/17 : COPY nginx.conf /etc/nginx/ ---> ba65da2b9c43 Step 4/17 : ARG CHANGE_SOURCE=false ---> Running in 1d31fc76ab76 Removing intermediate container 1d31fc76ab76 ---> 8864e5fb904e Step 5/17 : RUN if [ ${CHANGE_SOURCE} = true ]; then sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/' /etc/apk/repositories ;fi ---> Running in d0f8c3bd67dd Removing intermediate container d0f8c3bd67dd ---> c6e0c7aaf66f Step 6/17 : RUN apk update && apk upgrade && apk --update add logrotate && apk add --no-cache openssl && apk add --no-cache bash ---> Running in 37305c5f0e55 fetch http://dl-cdn.alpinelinux.org/alpine/v3.10/main/x86_64/APKINDEX.tar.gz ERROR: http://dl-cdn.alpinelinux.org/alpine/v3.10/main: network error (check Internet connection and firewall) WARNING: Ignoring APKINDEX.00740ba1.tar.gz: No such file or directory fetch http://dl-cdn.alpinelinux.org/alpine/v3.10/community/x86_64/APKINDEX.tar.gz ERROR: http://dl-cdn.alpinelinux.org/alpine/v3.10/community: network error (check Internet connection and firewall) WARNING: Ignoring APKINDEX.d8b2a6f4.tar.gz: No such file or directory 2 errors; 36 distinct packages available ERROR: Service 'nginx' failed to build: The command '/bin/sh -c apk update && apk upgrade && apk --update add logrotate && apk add --no-cache openssl && apk add --no-cache bash' returned a non-zero code: 2

Uso un ubuntu 18.04 ¿Podría decirme cómo se soluciona?