E: Unable to locate package python3-pip

[realwangyibo]

想把 flask 应用构建成 docker 镜像，然后遇到了这个错误

sources.list 是网易的 apt 源

Dockerfile:

FROM ubuntu:14.04

COPY ./sources.list /etc/apt/sources.list

RUN apt-get -y update
RUN apt-get -y install python3 \
python3-pip
#python3-setuptools

以下略

镜像构建信息：

Sending build context to Docker daemon 57.34 kB
Step 1 : FROM ubuntu:14.04
 ---> 1e0c3dd64ccd
Step 2 : COPY ./sources.list /etc/apt/sources.list
 ---> Using cache
 ---> 6071fba143f6
Step 3 : RUN apt-get -y update
 ---> Using cache
 ---> 184f7abcfd21
Step 4 : RUN apt-get -y install python3 python3-pip
 ---> Running in 5b8295da4a82
Reading package lists...
Building dependency tree...
Reading state information...
E: Unable to locate package python3-pip
The command '/bin/sh -c apt-get -y install python3 python3-pip' returned a non-zero code: 100