运行docker-compose build
W: GPG error: http://archive.ubuntu.com/ubuntu precise-updates InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 49976Egf897D05B6
E: The repository 'http://archive.ubuntu.com/ubuntu precise-updates InRelease' is not signed.
W: GPG error: http://archive.ubuntu.com/ubuntu precise-backports InRelease: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 49976Egf897D05B6
E: The repository 'http://archive.ubuntu.com/ubuntu precise-backports InRelease' is not signed.
W: GPG error: http://archive.ubuntu.com/ubuntu precise Release: The following signatures couldn't be verified because the public key is not available: NO_PUBKEY 49976Egf897D05B6
E: The repository 'http://archive.ubuntu.com/ubuntu precise Release' is not signed.
这是我的Dockerfile的样子...
FROM php:7.2-apache
RUN apt-get -y update && apt-get install -y software-properties-common
RUN add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu precise universe" && \
add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu precise main restricted universe multiverse" && \
add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu precise-updates main restricted universe multiverse" && \
add-apt-repository -y "deb http://archive.ubuntu.com/ubuntu precise-backports main restricted universe multiverse"
RUN apt-get update && apt-get install -y --allow-unauthenticated\
software-properties-common \
python-dev \
python-pip \
s3cmd \
cuneiform \
poppler-utils \
&& apt-get clean \
&& rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* \
&& docker-php-ext-configure pdo_mysql --with-pdo-mysql=mysqlnd \
&& docker-php-ext-install \
opcache
第3步弹出错误（运行apt-get更新时）。