mecabの辞書はipadicです。
File構成
dir/
├ Dockerfile
├ docker-compose.yml
└ requirements.txt
Dockerfile
FROM ubuntu:20.04
USER root
RUN apt update
RUN apt install -y python3-pip
RUN apt -y install build-essential libssl-dev libffi-dev python3-dev
RUN apt -y install mecab libmecab-dev mecab-utils mecab-ipadic mecab-ipadic-utf8 python3-mecab
RUN apt -y install locales && \
localedef -f UTF-8 -i ja_JP ja_JP.UTF-8
ENV LANG ja_JP.UTF-8
ENV LANGUAGE ja_JP:ja
ENV LC_ALL ja_JP.UTF-8
ENV TZ JST-9
ENV TERM xterm
ADD requirements.txt .
RUN apt-get install -y vim less
RUN apt-get install -y libhdf5-dev
RUN pip3 install --upgrade pip
RUN pip install --upgrade setuptools
RUN pip install -r requirements.txt
requirements.txt
mecab-python
unidic-lite //なくても動く
references
Python 3をインストールしUbuntu 20.04サーバーにプログラミング環境を設定する方法
(https://www.digitalocean.com/community/tutorials/how-to-install-python-3-and-set-up-a-programming-environment-on-an-ubuntu-20-04-server-ja)
【Python】形態素解析エンジン MeCabの使い方
(https://hibiki-press.tech/python/mecab/5153)
MeCab のインストール（Ubuntu 上）
(https://www.kkaneko.jp/tools/ubuntu/ubuntu_mecab.html)