Dockerfile with the newest asdf installed, which takes .tool-version from the current folder, installs plugins, and all versions.

Dockerfile

# syntax=docker/dockerfile:1
FROM ubuntu:latest

LABEL maintainer='Marek Pankowski <mkpanq.com>'
LABEL last-update='2025-08-03'

SHELL ["/bin/bash", "-l", "-c"]

# Be sure to install the proper version of asdf
# Available version type for each tag:
# linux-arm64
# linux-386
# linux-amd64
# darwin-amd64
# darwin-arm64
ARG PACKAGE_VERSION="linux-arm64"

RUN apt-get update && apt-get upgrade -y && apt-get install -y \
  curl \
  git \
  tar \
  && a_pt-get clean \
  && rm -rf /var/lib/apt/lists/*
WORKDIR /root
RUN tag=$(curl --silent "https://api.github.com/repos/asdf-vm/asdf/tags" | jq -r '.[0].name') \
    && curl -L https://github.com/asdf-vm/asdf/releases/download/$tag/asdf-$tag-${PACKAGE_VERSION}.tar.gz --output asdf-arm64.tar.gz \
    && tar -xzf asdf-arm64.tar.gz \
    && rm -rf asdf-arm64.tar.gz

RUN mv asdf /usr/local/bin && chmod +x /usr/local/bin/asdf
ENV PATH="/usr/local/bin:${PATH}"

COPY .tool-versions /root/.tool-versions
RUN for tool in $(awk '{print $1}' < .tool-versions); do \
      if ! asdf plugin list | grep -q "^$tool\$"; then \
        asdf plugin add $tool; \
      fi; \
    done && \
    asdf install && \
    asdf reshim