docker: add docker image for building

docker/Dockerfile

@@ -0,0 +1,83 @@
+FROM debian:10
+
+ENV DEBIAN_FRONTEND=noninteractive
+
+RUN apt-get update \
+  && apt-get install --no-install-suggests --no-install-recommends -y \
+  apt-utils \
+  libnss-wrapper \
+  && apt-get install --no-install-suggests --no-install-recommends -y \
+  build-essential \
+  net-tools \
+  autoconf \
+  m4 \
+  bison \
+  flex \
+  g++ \
+  libtool \
+  sqlite \
+  gcc \
+  binutils \
+  patch \
+  bzip2 \
+  make \
+  gettext \
+  unzip \
+  zlib1g-dev \
+  libc6 \
+  gperf \
+  automake \
+  groff \
+  lib32stdc++6 \
+  libncurses5 \
+  libncurses5-dev \
+  gawk \
+  gitk \
+  zlib1g-dev \
+  autopoint \
+  shtool \
+  autogen \
+  mtd-utils \
+  gcc-multilib \
+  gconf-editor \
+  lib32z1-dev \
+  pkg-config \
+  libssl-dev \
+  automake1.11 \
+  libmnl-dev \
+  libxml2-dev \
+  intltool \
+  libglib2.0-dev \
+  libstdc++5 \
+  texinfo \
+  dos2unix \
+  xsltproc \
+  libnfnetlink0 \
+  libcurl4-openssl-dev \
+  libgtk2.0-dev \
+  libnotify-dev \
+  libevent-dev \
+  git \
+  re2c \
+  texlive \
+  libelf1 \
+  nodejs \
+  zip \
+  mc \
+  cmake \
+  curl \
+  linux-headers-4.19.0-9-all \
+  && dpkg --add-architecture i386 \
+  && apt-get update \
+  && apt-get install --no-install-suggests --no-install-recommends -y \
+  libelf1:i386 \
+  libelf-dev:i386 \
+  && apt-get remove -y 'libicu-dev*' 'uuid-dev*' \
+  && rm -rf /var/lib/apt/lists/*
+
+COPY nss_wrapper /usr/bin/
+
+# Map user and dont run as root
+USER 65534
+ENTRYPOINT ["nss_wrapper"]
+CMD ["bash"]

docker/Makefile

@@ -0,0 +1,21 @@
+VERSION  ?= latest
+DOCKER   ?= docker
+IMG_NAME ?= freshtomato
+
+build_freshtomato: .freshtomato.docker_built
+
+.freshtomato.docker_built: Dockerfile nss_wrapper
+	$(DOCKER) build -t $(IMG_NAME):$(VERSION) .
+	touch .freshtomato.docker_built
+
+run_freshtomato: .freshtomato.docker_built
+	$(DOCKER) run -v $(abspath ../):/ws -it --user $(shell id -u):$(shell id -g) $(IMG_NAME):$(VERSION) /bin/bash
+
+build.%: .freshtomato.docker_built
+	$(DOCKER) run -v $(abspath ../):/ws -it --user $(shell id -u):$(shell id -g) $(IMG_NAME):$(VERSION) make -C /ws/release/src-rt-6.x.4708 $(subst build.,,$@)
+
+clean:
+	rm -f .freshtomato.docker_built
+
+help:
+	@make -s -C ../release/src-rt-6.x.4708 help | sed 's,^[a-z],build.&,g'

docker/nss_wrapper

@@ -0,0 +1,22 @@
+#!/bin/bash
+
+# Set current user in nss_wrapper
+USER_ID=$(id -u)
+GROUP_ID=$(id -g)
+
+if [ x"$USER_ID" != x"0" ]; then
+
+    NSS_WRAPPER_PASSWD=/tmp/passwd
+    NSS_WRAPPER_GROUP=/etc/group
+
+    cat /etc/passwd > $NSS_WRAPPER_PASSWD
+
+    echo "default:x:${USER_ID}:${GROUP_ID}:Default Build User:${HOME}:/bin/bash" >> $NSS_WRAPPER_PASSWD
+
+    export NSS_WRAPPER_PASSWD
+    export NSS_WRAPPER_GROUP
+
+    export LD_PRELOAD=libnss_wrapper.so
+fi
+
+exec "$@"