Official container image?

[dkratunov]

It is somewhat difficult to build and run bpftune in a containerized environment.

Below is my first attempt, if it's of any help to others, though it is quite flawed.

# syntax=docker/dockerfile:1

FROM alpine:3.21 AS builder

RUN echo "http://dl-cdn.alpinelinux.org/alpine/v3.21/main" > /etc/apk/repositories && \
    echo "http://dl-cdn.alpinelinux.org/alpine/v3.21/community" >> /etc/apk/repositories 

RUN apk update
RUN apk add libbpf-dev libcap-dev linux-tools linux-headers libnl3-dev clang llvm git binutils-dev
RUN apk add make bpftool gcompat coreutils py3-docutils musl-utils

## bpftune build

RUN git clone https://github.com/oracle/bpftune.git /bpftune
WORKDIR /bpftune
RUN git checkout b0f6187c6d0b9993f5c14d47831b18511dfcf388

# Patch for musl
COPY ./bpftune-0001-sigval.patch .
RUN git apply bpftune-0001-sigval.patch

RUN mkdir out && make -j16 && make srcinstall DESTDIR=/bpftune/out

## actual image

FROM alpine:3.21 AS base

COPY --from=builder /bpftune/out /bpftune
COPY ./bpftune.sh /bpftune/bpftune.sh
RUN chmod +x /bpftune/bpftune.sh

RUN echo "http://dl-cdn.alpinelinux.org/alpine/v3.21/main" > /etc/apk/repositories && \
    echo "http://dl-cdn.alpinelinux.org/alpine/v3.21/community" >> /etc/apk/repositories

RUN apk update
RUN apk add bash

CMD /bin/bash -c "mount -t debugfs none /sys/kernel/debug && /bin/bash"

The musl patch is as follows:

diff --git a/src/Makefile b/src/Makefile
index cdb7f65..ed24ed5 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -124,7 +124,7 @@ $(OPATH):
 	mkdir $(OPATH)
 
 analyze: $(BPF_SKELS) $(LEGACY_BPF_SKELS) $(NOBTF_BPF_SKELS)
-	$(CLANG) --analyze $(INCLUDES) libbpftune.c bpftune.c $(TUNER_SRCS)
+	$(CLANG) --analyze $(INCLUDES) -Wno-incompatible-pointer-types libbpftune.c bpftune.c $(TUNER_SRCS)
 clean:
 	$(call QUIET_CLEAN, bpftune)
 	$(Q)$(RM) $(OPATH)*.o *.d $(OPATH)*.so*
diff --git a/src/libbpftune.c b/src/libbpftune.c
index f4bec2f..3c0c28e 100644
--- a/src/libbpftune.c
+++ b/src/libbpftune.c
@@ -50,6 +50,13 @@
 #include <time.h>
 #include <pthread.h>
 
+#ifdef __MUSL__
+typedef union {
+    int sival_int;
+    void *sival_ptr;
+} sigval_t;
+#endif
+
 unsigned short bpftune_learning_rate;
 
 #include <bpftune/libbpftune.h>
@@ -1838,7 +1845,7 @@ static void bpftuner_strategy_update(struct bpftuner *tuner)
 		bpftuner_strategy_set(tuner, max_strategy);
 }
 
-static void bpftuner_strategy_timeout(sigval_t sigval)
+static void bpftuner_strategy_timeout(union sigval sigval)
 {
 	struct bpftuner *tuner = sigval.sival_ptr;
 
@@ -2092,7 +2099,7 @@ void *bpftune_server_thread(void *arg)
 	if (port == 0) {
 		len = sizeof(saddr);
 
-		if (!getsockname(fd, &saddr, &len))
+		if (!getsockname(fd, (struct sockaddr *)&saddr, &len))
 			port = ntohs(saddr.sin_port);
 	}
 	if (port != 0) {
@@ -2113,7 +2120,7 @@ void *bpftune_server_thread(void *arg)
 		char buf[BPFTUNE_SERVER_MSG_MAX];
 		char req[80];
 		struct sockaddr_in caddr;
-		int cfd = accept(fd, (struct sockaddr_in *)&caddr, &len);
+		int cfd = accept(fd, (struct sockaddr *)&caddr, &len);
 		unsigned long i;
 
 		if (cfd < 0) {

bpftune.sh:

#!/bin/bash
LD_LIBRARY_PATH=/bpftune/usr/lib:/bpftune/usr/lib64:$LD_LIBRARY_PATH exec /bpftune/usr/sbin/bpftune $@

Even after all this effort, bpftune still expects /usr/lib64/bpftune to exist so you have to symlink /bpftune/usr/lib64/bpftune there yourself.

All this is to say, I'd really appreciate an official image :)