How to install Russian encoding in Ubuntu docker container?

Question

Docker

Our project writes logs in Russian to stdout
Everything was fine in vm, we decided to move to a container. Ubuntu was chosen.
Russian locale is not installed.
RUN locale-gen ru_RU.UTF-8 && dpkg-reconfigure locales
doesn't help
.
#locale
LANG=
LANGUAGE=
LC_CTYPE="POSIX"
LC_NUMERIC="POSIX"
LC_TIME="POSIX"
LC_COLLATE="POSIX"
LC_MONETARY="POSIX"
LC_MESSAGES="POSIX"
LC_PAPER="POSIX"
LC_NAME="POSIX"
LC_ADDRESS="POSIX "
LC_TELEPHONE="POSIX"
LC_MEASUREMENT="POSIX"
LC_IDENTIFICATION="POSIX"

Answer 1

сам задал, сам отвечаю
FROM ubuntu:16.04
#не задавать вопросов
ENV DEBIAN_FRONTEND noninteractive.
RUN apt-get update
RUN apt-get upgrade -y
RUN apt-get install -y language-pack-ru
ENV LANGUAGE ru_RU.UTF-8
ENV LANG ru_RU.UTF-8
ENV LC_ALL ru_RU.UTF-8
RUN locale-gen ru_RU.UTF-8 && dpkg-reconfigure locales
ENTRYPOINT /bin/bash
пока получилось только так. создаю свой образ с убунтой и уже из него свои приложения