From 95c92b8db70565d55a9030aec45b76ea153803f1 Mon Sep 17 00:00:00 2001
From: toby cabot <toby@caboteria.org>
Date: Wed, 10 May 2023 17:33:11 -0400
Subject: [PATCH 1/3] Update Dockerfile to work with golang 1.20 base image

The previous base image (Ubuntu 20.10) was a non-LTS release and is
now unsupported so the Docker build command failed because it couldn't
find the apt repos.

Using golang base images simplifies the Dockerfile (since we no longer
need to install golang ourselves) and since they're based on Debian
Bullseye they'll be supported for a while.
---
 Dockerfile | 17 ++---------------
 Makefile   |  3 +--
 2 files changed, 3 insertions(+), 17 deletions(-)

diff --git a/Dockerfile b/Dockerfile
index 1fbb0ca..53a1804 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,26 +1,13 @@
-FROM ubuntu:20.10
-
-# Define variables.
-ARG GOVERSION=1.15.15
-ARG ARCH=amd64
+FROM golang:1.20-bullseye
 
 # Download development environment.
 RUN apt-get update && \
     apt-get install -y \
-        libbpf-dev \
-        make \
         clang \
         llvm \
+        libbpf-dev \
         libelf-dev
 
-# Install Go specific version.
-RUN apt-get install -y wget && \
-    wget https://golang.org/dl/go${GOVERSION}.linux-${ARCH}.tar.gz && \
-    tar -xf go${GOVERSION}.linux-${ARCH}.tar.gz && \
-    mv go/ /usr/local/ && \
-    ln -s /usr/local/go/bin/go /usr/local/bin/ && \
-    rm -rf go${GOVERSION}.linux-${ARCH}.tar.gz
-
 # Setup working directory.
 RUN mkdir -p /app
 WORKDIR /app
diff --git a/Makefile b/Makefile
index 09092c8..2449ec2 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ all: $(TARGET) $(TARGET_BPF)
 
 go_env := CC=clang CGO_CFLAGS="-I $(LIBBPF_HEADERS)" CGO_LDFLAGS="$(LIBBPF_OBJ)"
 $(TARGET): $(GO_SRC)
-	$(go_env) go build -o $(TARGET) 
+	$(go_env) go build -o $(TARGET) -buildvcs=false
 
 $(TARGET_BPF): $(BPF_SRC)
 	clang \
@@ -25,4 +25,3 @@ $(TARGET_BPF): $(BPF_SRC)
 .PHONY: clean
 clean:
 	go clean
-	
\ No newline at end of file

From 39805fc690b96a30ca9866220eae6a2efe11e6cb Mon Sep 17 00:00:00 2001
From: toby cabot <toby@caboteria.org>
Date: Wed, 10 May 2023 17:36:27 -0400
Subject: [PATCH 2/3] Allow user to specify make target when running Docker
 image

The make target used to be hard-coded in the Docker entrypoint so you
could only make the "all" target. Now the target is in the CMD so you
can override it, e.g.:

  $ docker run --rm -v $(pwd)/:/app/:z hello clean

The default behavior is the same as before, i.e., "make all".
---
 Dockerfile | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/Dockerfile b/Dockerfile
index 53a1804..234cd10 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -13,4 +13,5 @@ RUN mkdir -p /app
 WORKDIR /app
 
 # Execute build command.
-ENTRYPOINT ["/usr/bin/make", "all"]
+ENTRYPOINT ["/usr/bin/make"]
+CMD ["all"]

From ed85ae895e90452530baa96e813ba17c3e8c129b Mon Sep 17 00:00:00 2001
From: toby cabot <toby@caboteria.org>
Date: Wed, 17 May 2023 09:08:27 -0400
Subject: [PATCH 3/3] Rebuild when headers (or Makefile) change

---
 Makefile | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/Makefile b/Makefile
index 2449ec2..e6dfd61 100644
--- a/Makefile
+++ b/Makefile
@@ -3,8 +3,8 @@ ARCH=$(shell uname -m)
 TARGET := hello
 TARGET_BPF := $(TARGET).bpf.o
 
-GO_SRC := *.go
-BPF_SRC := *.bpf.c
+GO_SRC := *.go Makefile
+BPF_SRC := *.bpf.c *.bpf.h Makefile
 
 LIBBPF_HEADERS := /usr/include/bpf
 LIBBPF_OBJ := /usr/lib/$(ARCH)-linux-gnu/libbpf.a