How to install conda inside a Dockerfile?

(everything must put under one line inside Dockerfile)

# to install conda and torch
ENV CONDA_DIR /opt/conda
RUN wget --quiet https://repo.anaconda.com/miniconda/Miniconda3-latest-Linux-x86_64.sh -O ~/miniconda.sh
RUN /bin/bash ~/miniconda.sh -b -p /opt/conda
RUN . /root/.bashrc && \
    /opt/conda/bin/conda init bash && \
    /opt/conda/bin/conda create -n torch110 python=3.8 pytorch torchvision torchaudio cudatoolkit=11.1 -c pytorch-lts -c nvidia -y

bash.sh in the host:-

export PYTHONPATH=/usr/local/opencv4/python3
export LD_LIBRARY_PATH=/usr/local/cuda/compat/lib.real:/opt/tritonserver/lib:/usr/src/tensorrt/lib:/opt/jarvis/lib/:/opt/kenlm/lib/:/opt/tritonserver/lib/pytorch/:/usr/local/cuda/compat/lib:/usr/local/nvidia/lib:/usr/local/nvidia/lib64:/usr/local/lib:/usr/local/server2012/lib:/opt/conda/envs/torch110/lib/
eval "$(conda shell.bash hook)"
conda activate torch110
cd /data/example
python main.py
conda deactivate