更改源

源1：

RUN sed -i 's/dl-cdn.alpinelinux.org/mirrors.aliyun.com/g' /etc/apk/repositories

源2：

RUN echo "https://mirror.tuna.tsinghua.edu.cn/alpine/v3.4/main/" > /etc/apk/repositories

安装bash命令

RUN apk update \
        && apk upgrade \
        && apk add --no-cache bash \
        bash-doc \
        bash-completion \
        && rm -rf /var/cache/apk/* \
        && /bin/bash

RUN apk add -U tzdata \
    && cp /usr/share/zoneinfo/Asia/Shanghai /etc/localtime \
    && echo "Asia/Shanghai" > /etc/timezone \
    && apk add --no-cache bash bash-doc bash-completion \
    && apk del tzdata \
    && rm -rf /var/cache/apk/* \
    && /bin/bash