Add riscv Dockerfile builder

Makefile

@@ -105,6 +105,12 @@ else
 $(error error: invalid ARCH; "$(ARCH)")
 endif
 
+ifeq ("riscv64", "$(ARCH)")
+	DIST=ubunturiscv
+else
+	DIST=ubuntu
+endif
+
 # include the CLI targets with "cli" prefix plus "scope" shortcut
 cli%:
 	@$(MAKE) -C cli $(@:cli%=%)
@@ -129,7 +135,6 @@ docker-run-alpine:
 	@$(MAKE) -s build CMD="$(CMD)" DIST="alpine"
 
 # build in our builder container for the given ARCH
-build: DIST ?= ubuntu
 build: CMD ?= make all test
 build: require-docker require-qemu-binfmt
 	@[ -n "$(NOBUILD)" ] || $(MAKE) -s builder DIST="$(DIST)" ARCH="$(ARCH)"
@@ -143,14 +148,12 @@ build: require-docker require-qemu-binfmt
 	       	$(CMD)
 
 # run a shell our builder container without starting a build
-run: DIST ?= ubuntu
 run: CMD ?= /bin/bash --login
 run:
 	@echo Running the AppScope $(DIST)/$(ARCH) Builder Container
 	@$(MAKE) -s build DIST="$(DIST)" ARCH="$(ARCH)" CMD="$(CMD)"
 
 # get another shell in an existing builder container
-exec: DIST ?= ubuntu
 exec: CMD ?= /bin/bash
 exec:
 	@[ -n "$(shell docker ps -q -f "name=appscope-builder-$(DIST)-$(ARCH)")" ] || \
@@ -159,7 +162,6 @@ exec:
 	@docker exec -it $(shell docker ps -q -f "name=appscope-builder-$(DIST)-$(ARCH)") $(CMD)
 
 # build the builder image for the given ARCH
-builder: DIST ?= ubuntu
 builder: TAG := $(BUILD_IMAGE):$(DIST)-$(ARCH)
 builder: require-docker-buildx-builder
 	@[ -z "$(CI)" ] || echo "Update $(DIST)/$(ARCH) Builder Image"

docker/builder/Dockerfile.ubunturiscv

@@ -0,0 +1,70 @@
+
+ARG IMAGE=riscv64/ubuntu:23.04
+FROM $IMAGE
+
+# These are needed to bypass the prompts when tzdata is installed.
+ENV DEBIAN_FRONTEND="noninteractive"
+ENV TZ="America/New_York"
+RUN ln -snf /usr/share/zoneinfo/$TZ /etc/localtime && echo $TZ > /etc/timezone
+
+# ---
+# Install packages. Note extra PPA for Go.
+#
+# Also note that this logic duplicates the top-level `install_build_tools.sh`
+# script. Trying to use that script here causes issues because of its use of
+# `sudu` when running the package installer. It clears the environment so the
+# additions above don't apply and we end up with interaction when some of the
+# dependencies (i.e. tzdata) are installed.
+#
+RUN apt-get update && \
+    apt-get install -y software-properties-common gpg apt-utils libelf-dev && \
+    add-apt-repository ppa:longsleep/golang-backports && \
+    apt-get update && \
+    apt-key adv --keyserver keyserver.ubuntu.com --recv-keys 52B59B1571A79DBC054901C0F6BC817356A3D45E && \
+    apt-get install -y \
+        autoconf \
+        automake \
+        build-essential \
+        cmake \
+        curl \
+        emacs \
+        gdb \
+        git \
+        golang-go \
+        lcov \
+        libtool \
+        lsof \
+        make \
+        strace \
+        sudo \
+        tzdata \
+        && \
+    dpkg-reconfigure --frontend noninteractive tzdata && \
+    apt-get clean
+
+RUN useradd -d /home/builder -m builder && \
+    useradd -d /home/builder -m builder1 && \
+    \
+    echo "builder ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers.d/builder && \
+    echo "builder1 ALL=(ALL) NOPASSWD: ALL" >> /etc/sudoers.d/builder && \
+    \
+    echo "alias ll='ls -alF'" >> /home/builder/.bashrc && \
+    echo "alias la='ls -A'" >> /home/builder/.bashrc && \
+    echo "alias l='ls -CF'" >> /home/builder/.bashrc && \
+    echo "alias h='history'" >> /home/builder/.bashrc && \
+    \
+    echo "#set environment LD_PRELOAD=/home/builder/appscope/lib/linux/libscope.so" >> /home/builder/.gdbinit && \
+    echo "set follow-fork-mode child" >> /home/builder/.gdbinit && \
+    echo "set breakpoint pending on" >> /home/builder/.gdbinit && \
+    echo "set directories /home/builder/appscope" >> /home/builder/.gdbinit && \
+    \
+    mkdir /home/builder/appscope
+
+# ---
+# The local git clone of the project is mounted as /home/builder/appscope. See Makefile.
+#
+#     docker run -v $(pwd):/home/builder/appscope ...
+#
+WORKDIR /home/builder/appscope
+
+# fini

docs/BUILD.md

@@ -23,13 +23,13 @@ You can override the command setting `CMD` like below.
 make build CMD="make coreall"
 ```
 
-By default, this will build for the local CPU architecture; `uname -m`. We support building for other architectures via [QEMU] and [`binfmt`] by setting `ARCH` like below. Note we only support `x86_64` and `aarch64` currently
+By default, this will build for the local CPU architecture; `uname -m`. We support building for other architectures via [QEMU] and [`binfmt`] by setting `ARCH` like below. Note we only support `x86_64`, `aarch64` and `riscv64` currently
 
 ```text
 make build ARCH=aarch64
 ```
 
-The resulting binaries are listed below. `$ARCH` will be `x86_64` or `aarch64`.
+The resulting binaries are listed below. `$ARCH` will be `x86_64`, `aarch64` or `riscv64`.
 
 * `lib/linux/$ARCH/libscope.so`
 * `bin/linux/$ARCH/scope`