Auto load overlay kernel module for apptainer

Makefile

@@ -1,6 +1,6 @@
 # Change this to podman if you are on RHEL8+
 DOCKER ?= docker
-SINGULARITY ?= singularity
+APPTAINER ?= apptainer
 SHARED_DIR ?= ./shared
 OVERLAY_DIR ?= ./overlay
 MAX_THREADS ?= 16
@@ -17,17 +17,26 @@ GID := $(shell id -g)
 p4iab.tar.gz: .docker_build
 	"$(DOCKER)" save p4iab:latest | gzip > "$@"
 
-p4iab.sif: p4iab.def p4iab.tar.gz
-	sudo "$(SINGULARITY)" build "$@" "$<"
+p4iab.sif: p4iab.def .docker_build
+	sudo "$(APPTAINER)" build "$@" "$<"
 	sudo chown $(UID):$(GID) "$@"
 
-run: .docker_build
-	mkdir -p "$(SHARED_DIR)"
-	"$(DOCKER)" run --rm -it --privileged -v "$(SHARED_DIR):/home/p4/shared" -e TERM -u p4 --entrypoint p4iab_docker_entry.sh p4iab:latest
+run:
+	@mkdir -p "$(SHARED_DIR)"
+	@test -n "$(shell docker image ls -q p4iab)" \
+		|| (echo Cannot find image p4iab:latest, has it been built yet? 1>&2 \
+		&& false)
+	@"$(DOCKER)" run --rm -it --privileged -v "$(SHARED_DIR):/home/p4/shared" \
+		-e TERM -u p4 --entrypoint p4iab_docker_entry.sh p4iab:latest
 
-sc-run: p4iab.sif
-	mkdir -p "$(SHARED_DIR)" "$(OVERLAY_DIR)"
-	sudo singularity run --allow-setuid --overlay "$(OVERLAY_DIR)" -B "$(SHARED_DIR):/home/p4/shared" "$<"
+app-run:
+	@mkdir -p "$(SHARED_DIR)" "$(OVERLAY_DIR)"
+	@test -e p4iab.sif \
+		|| (echo Cannot find p4iab.sif, has it been built yet? 1>&2 \
+		&& false)
+	@lsmod | grep overlay > /dev/null || sudo modprobe overlay
+	@sudo $(APPTAINER) run --allow-setuid --overlay "$(OVERLAY_DIR)" \
+		-B "$(SHARED_DIR):/home/p4/shared" p4iab.sif
 
 clean:
 	"$(DOCKER)" container prune

README.md

@@ -24,46 +24,63 @@ this container also has a few other advantages:
 2. It can run with a variety of setups: Docker, Podman, K8S, OpenShift, etc...
 3. It can be used as a basis for other P4 runtime testing suites.
 4. It's much smaller than a VM image.
-5. When converted into a singularity container, it can be launched as a single
-   binary executable.
+5. When converted into a Apptainer SIF, it can be launched as a single binary
+   executable.
+
+User Tools
+----------
+
+The containers are built with several additional user tools already in place,
+including but not limited to:
+
+1. `vim`/`emacs`: text editing.
+2. `git`: version control.
+3. `tmux`: terminal multiplexing.
+3. `tshark`/`termshark`/`tcpdump`: packets inspection.
+4. `htop`: visual overview of processes.
+5. `man`/`less`: documentation support.
 
 How to Use
 ----------
 
 There are two ways of launching P4-in-a-Bottle:
 
-### Singularity
+### Apptainer
 
-Singularity is a container runtime by Sylabs developed specificly for software
-that require low-level access to hardware (i.e. NVIDIA drivers, network
-devices). This is great for P4-in-a-Bottle, since Mininet requires access to
+Apptainer is a new container runtime developed specificly for software that
+require low-level access to hardware (i.e. NVIDIA drivers, network devices,
+etc). This is great for P4-in-a-Bottle, since Mininet requires access to
 networking kernel components to work.
 
-Unfortunately, Singularity only works natively on Linux, so if you're on Mac or
+Unfortunately, Apptainer only works natively on Linux, so if you're on Mac or
 Windows (without WSL), you're out-of-luck here and should proceed to the docker
 instructions below.
 
-To use P4-in-a-Bottle with Singularity:
-1. Install singularity from [GitHub](https://github.com/sylabs/singularity/releases).
-2. Download a pre-built image `p4iab.sif` and place it in the same directory
-   as this README. If you skip this step YOU WILL BUILD BOTH THE DOCKER
-   CONTAINER AND THE SINGULARITY CONTAINER FROM SOURCE. (Trust me, you do NOT
-   want to build this yourself).
-3. Run `make sc-run`. A shared directory `shared/` will be created to allow
+To use P4-in-a-Bottle with Apptainer:
+1. Install Apptainer from [GitHub](https://github.com/apptainer/apptainer/releases).
+2. Clone and cd into this repository.
+3. Download a pre-built image
+   [p4iab.sif](https://git.inkweaver.net/inkweaver/P4-in-a-Bottle/releases)
+   and place it in the same directory alongside `README.md`.
+4. Run `make app-run`. A shared directory `shared/` will be created to allow
    you to move files between the container and your system.
 
 ### Docker
 
-If you are stuck with docker, don't panic! The instructions are longer but
-everything should still work.
+If you are stuck with docker, don't panic! The instructions are slightly more
+complicated but everything should still work.
 1. Install docker on your system. This should be pretty self-explanatory.
-2. Download a pre-built image `p4iab.tar.gz` and place it in the same directory
-   as this README. Then run `docker load -i p4iab.tar.gz && touch .docker_build`.
-   If you skip this step YOU WILL BUILD THE DOCKER CONTAINER FROM SOURCE. Do
-   so only if you know what you are doing.
-3. Run `make run`. A shared directory `shared/` will be created to allow
+2. Clone and cd into this repository.
+3. Download a pre-built image
+   [p4iab.tar.gz](https://git.inkweaver.net/inkweaver/P4-in-a-Bottle/releases)
+   and place it in the same directory alongside `README.md`.
+4. Run `docker load -i p4iab.tar.gz` to import the container into docker.
+5. Run `make run`. A shared directory `shared/` will be created to allow
    you to move files between the container and your system.
 
+Regardless of which method you run the container, you will be dropped into a
+shell with the user P4. The password for the P4 user account is simply `p4`.
+
 
 Building from Source
 --------------------
@@ -80,10 +97,13 @@ $ make .docker_build
 # Building a docker image that can be imported on other machines
 $ make p4iab.tar.gz
 
-# Building a singularity image (This depends on the docker image)
+# Building a Apptainer image (This depends on the docker image)
 $ make p4iab.sif
 
 # Cleanup any cached artifacts
 $ make clean
 ```
 
+Once you have either `p4iab.tar.gz` or `p4iab.sif`, proceed to follow the
+instructions in the "How to Use" section from step 4.
+

p4iab.def

@@ -1,5 +1,5 @@
-BootStrap: docker-archive
-From: p4iab.tar.gz
+BootStrap: docker-daemon
+From: p4iab:latest
 
 %files
     scripts/p4iab_singularity_entry.sh /usr/bin/p4iab_singularity_entry.sh