it boots

Dockerfile

@@ -1,23 +1,31 @@
-FROM debian:bookworm-slim
+FROM ubuntu:22.04
 
 ENV DEBIAN_FRONTEND=noninteractive
 
-# Install packages
+# Install base packages and enable the dosemu2 PPA
 RUN apt-get update && \
     apt-get install -y --no-install-recommends \
+      software-properties-common \
+      gnupg \
       openssh-server \
-      dosemu2 \
-      dosbox-staging \
       busybox-static \
       sudo \
       ca-certificates \
       curl \
+      mtools \
+      unzip \
+      file \
+      && add-apt-repository -y ppa:dosemu2/ppa && \
+      apt-get update && \
+      apt-get install -y --no-install-recommends \
+        dosemu2 \
       && rm -rf /var/lib/apt/lists/*
 
-# Provide DOS wrapper and service supervisor
-COPY dos-shell /usr/local/bin/dos-shell
-COPY start-services.sh /usr/local/bin/start-dos-services
-RUN chmod +x /usr/local/bin/dos-shell /usr/local/bin/start-dos-services && \
+# Provide DOS wrapper, SvarDOS bootstrapper, and service supervisor
+COPY scripts/dos-shell /usr/local/bin/dos-shell
+COPY scripts/prepare-svardos.sh /usr/local/bin/prepare-svardos
+COPY scripts/start-services.sh /usr/local/bin/start-dos-services
+RUN chmod +x /usr/local/bin/dos-shell /usr/local/bin/start-dos-services /usr/local/bin/prepare-svardos && \
     echo "/usr/local/bin/dos-shell" >> /etc/shells
 
 # Create sshd runtime directory
@@ -29,14 +37,20 @@ RUN useradd -m -s /usr/local/bin/dos-shell dosuser && \
     echo "dosuser:dosuser" | chpasswd
 
 # Create directories for allowed DOS files and the C: drive mount
-RUN mkdir -p /opt/allowed_repo /cdrive /etc/dos_env && \
+RUN mkdir -p /opt/allowed_repo /cdrive /etc/dos_env /opt/svardos && \
     chown -R dosuser:dosuser /opt/allowed_repo /cdrive
 
+# Download and stage SvarDOS base files
+ARG SVARDOS_IMG_URL
+ENV SVARDOS_IMG_URL=${SVARDOS_IMG_URL}
+RUN /usr/local/bin/prepare-svardos && \
+    chown -R dosuser:dosuser /opt/svardos
+
 # Default allowed list (can be overridden with a bind mount)
-COPY dos_allowed /etc/dos_allowed
+COPY config/dos_allowed /etc/dos_allowed
 
 # Configure sshd to force command for dosuser
-COPY sshd_config /etc/ssh/sshd_config
+COPY config/sshd_config /etc/ssh/sshd_config
 
 EXPOSE 22 23
 CMD ["/usr/local/bin/start-dos-services"]

allowed_repo/.gitkeep

@@ -0,0 +1 @@
+*** End Patch

compose.yml

@@ -0,0 +1,21 @@
+services:
+  dos:
+    build:
+      context: .
+      args:
+        SVARDOS_IMG_URL: ${SVARDOS_IMG_URL:-}
+    image: ${DOS_IMAGE_NAME:-dos-env}
+    container_name: ${DOS_CONTAINER_NAME:-dos-env}
+    ports:
+      - "${DOS_SSH_PORT:-2222}:22"
+      - "${DOS_TELNET_PORT:-2323}:23"
+    environment:
+      DOS_ALLOW_MODE: ${DOS_ALLOW_MODE:-all}
+      ENABLE_TELNET: ${ENABLE_TELNET:-1}
+      TELNET_PORT: ${TELNET_PORT:-23}
+      TELNET_LOGIN: /bin/login
+    volumes:
+      - ./allowed_repo:/opt/allowed_repo
+      - ./config/dos_allowed:/etc/dos_allowed:ro
+      - ./dos_env:/etc/dos_env
+    restart: unless-stopped

dos_env/README.md

@@ -0,0 +1,8 @@
+# DOS Environment Templates
+
+Place optional template files here to customize the boot process:
+
+- `AUTOEXEC.BAT` – copied verbatim to `C:\AUTOEXEC.BAT` on each login.
+- `CONFIG.SYS` – copied to `C:\CONFIG.SYS` on each login.
+
+Leave this directory empty to use the defaults generated by `dos-shell`.

scripts/dos-shell

@@ -11,6 +11,8 @@ C_DRIVE="/cdrive"
 ENV_DIR="/etc/dos_env"
 AUTOEXEC_TEMPLATE="${ENV_DIR}/AUTOEXEC.BAT"
 CONFIG_TEMPLATE="${ENV_DIR}/CONFIG.SYS"
+SVARDOS_BASE="/opt/svardos/base"
+ALLOW_MODE="${DOS_ALLOW_MODE:-all}"   # default to exposing everything from the repo
 
 if [ "$(id -u)" -eq 0 ] && [ ! -d "${ENV_DIR}" ]; then
   mkdir -p "${ENV_DIR}"
@@ -20,9 +22,32 @@ fi
 rm -rf "${C_DRIVE:?}/"*
 mkdir -p "${C_DRIVE}"
 
-# Collect the list of allowed files and sync them into the C: drive
+# Seed the C: drive with the SvarDOS base image
+if [ -e "${SVARDOS_BASE}/COMMAND.COM" ] || [ -e "${SVARDOS_BASE}/command.com" ]; then
+  cp -a "${SVARDOS_BASE}/." "${C_DRIVE}/"
+else
+  echo "SvarDOS base not found in ${SVARDOS_BASE}. Aborting." >&2
+  exit 1
+fi
+
+# Sync additional DOS files into the C: drive
 allowed_entries=()
-if [ -f "${ALLOWED_LIST}" ]; then
+case "${ALLOW_MODE}" in
+  all)
+    if [ -d "${ALLOWED_REPO}" ] && [ "$(ls -A "${ALLOWED_REPO}")" ]; then
+      cp -a "${ALLOWED_REPO}/." "${C_DRIVE}/"
+    fi
+    ;;
+  list|allowlist)
+    ;;
+  *)
+    echo "Unknown DOS_ALLOW_MODE '${ALLOW_MODE}', falling back to allowlist mode." >&2
+    ALLOW_MODE="list"
+    ;;
+esac
+
+if [ "${ALLOW_MODE}" != "all" ]; then
+  if [ -f "${ALLOWED_LIST}" ]; then
     while IFS= read -r line || [ -n "$line" ]; do
       # trim whitespace
       line="$(printf '%s' "$line" | sed -e 's/^[[:space:]]*//' -e 's/[[:space:]]*$//')"
@@ -32,10 +57,9 @@ if [ -f "${ALLOWED_LIST}" ]; then
       esac
       allowed_entries+=("$line")
     done < "${ALLOWED_LIST}"
-fi
+  fi
 
-# Copy allowed files into the DOS C: drive
-for entry in "${allowed_entries[@]}"; do
+  for entry in "${allowed_entries[@]}"; do
     src="${ALLOWED_REPO}/${entry}"
     if [ -e "$src" ]; then
       dst_dir="$(dirname "${entry}")"
@@ -44,7 +68,8 @@ for entry in "${allowed_entries[@]}"; do
     else
       echo "Warning: allowed file not found: $src" >&2
     fi
-done
+  done
+fi
 
 # Optional: create an AUTOEXEC.BAT and CONFIG.SYS or other DOS boot files
 autoexec_path="${C_DRIVE}/AUTOEXEC.BAT"
@@ -60,7 +85,9 @@ echo Welcome to the containerized DOS environment.
 EOF
 fi
 
-if [ ${#allowed_entries[@]} -gt 0 ]; then
+if [ "${ALLOW_MODE}" = "all" ]; then
+  printf 'echo All repository programs are currently enabled.\r\n' >> "${autoexec_path}"
+elif [ ${#allowed_entries[@]} -gt 0 ]; then
   {
     printf 'echo Allowed programs:\r\n'
     for entry in "${allowed_entries[@]}"; do

scripts/prepare-svardos.sh

@@ -0,0 +1,79 @@
+#!/bin/bash
+set -euo pipefail
+
+SVARDOS_BASE_DIR="/opt/svardos/base"
+SVARDOS_CACHE="/opt/svardos/cache"
+SVARDOS_IMG="${SVARDOS_CACHE}/svardos.img"
+DEFAULT_REL="download/20250427/svardos-20250427-floppy-1.44M.zip"
+DEFAULT_BASE="http://svardos.org"
+
+if [ -z "${SVARDOS_IMG_URL:-}" ]; then
+  homepage="$(
+    curl -fsSL "${DEFAULT_BASE}/" 2>/dev/null || true
+  )"
+  discovered_rel=""
+  if [ -n "$homepage" ]; then
+    for pattern in 'download/[0-9]+/svardos-[0-9]+-floppy-1\.44M\.zip' 'download/[0-9]+/svardos-[0-9]+-usb\.zip'; do
+      candidate="$(printf '%s' "$homepage" | grep -Eo "$pattern" | head -n1)"
+      if [ -n "$candidate" ]; then
+        discovered_rel="$candidate"
+        break
+      fi
+    done
+  fi
+  if [ -n "$discovered_rel" ]; then
+    SVARDOS_IMG_URL="${DEFAULT_BASE}/${discovered_rel}"
+  else
+    SVARDOS_IMG_URL="${DEFAULT_BASE}/${DEFAULT_REL}"
+  fi
+fi
+
+if [ -e "${SVARDOS_BASE_DIR}/COMMAND.COM" ] || [ -e "${SVARDOS_BASE_DIR}/command.com" ]; then
+  exit 0
+fi
+
+mkdir -p "${SVARDOS_BASE_DIR}" "${SVARDOS_CACHE}"
+
+tmp_archive="${SVARDOS_CACHE}/svardos_download"
+rm -f "${tmp_archive}" "${SVARDOS_IMG}"
+
+echo "Fetching SvarDOS base from ${SVARDOS_IMG_URL}"
+curl -fsSL "${SVARDOS_IMG_URL}" -o "${tmp_archive}"
+
+mime_type="$(file -b --mime-type "${tmp_archive}")"
+case "${mime_type}" in
+  application/zip)
+    unzip -o "${tmp_archive}" -d "${SVARDOS_CACHE}" >/dev/null
+    ;;
+  application/x-bzip2|application/x-gzip|application/x-xz)
+    tar -xf "${tmp_archive}" -C "${SVARDOS_CACHE}"
+    ;;
+  application/octet-stream)
+    # assume this is already a raw image
+    cp "${tmp_archive}" "${SVARDOS_IMG}"
+    ;;
+  *)
+    echo "Unsupported SvarDOS payload type: ${mime_type}" >&2
+    exit 1
+    ;;
+esac
+
+if [ ! -f "${SVARDOS_IMG}" ]; then
+  # try to locate the image file
+  candidate="$(find "${SVARDOS_CACHE}" -maxdepth 1 -type f \( -iname '*svardos*.img' -o -iname '*.ima' -o -iname '*.img' \) | head -n1)"
+  if [ -z "${candidate}" ]; then
+    echo "Could not locate a SvarDOS disk image after extraction." >&2
+    exit 1
+  fi
+  mv "${candidate}" "${SVARDOS_IMG}"
+fi
+
+rm -rf "${SVARDOS_BASE_DIR}"/*
+mkdir -p "${SVARDOS_BASE_DIR}"
+
+# Copy contents of FAT image into the base directory
+mcopy -s -i "${SVARDOS_IMG}" ::* "${SVARDOS_BASE_DIR}/"
+
+rm -f "${SVARDOS_IMG}" "${tmp_archive}"
+rm -rf "${SVARDOS_CACHE}"
+echo "SvarDOS base copied to ${SVARDOS_BASE_DIR}"