Fix alpine docker build (#372)

This patch fixes the docker builds (`./build.sh` and
`./build-debug.sh`).

Two main things were broken:
* Alpine was missing a bcc-devel package. The temporary fix is to clone
  bcc, build, and install into the container
* Static linking against bcc was broken. I've made some cmake config
  changes to support this.

CMakeLists.txt

@@ -30,6 +30,8 @@ if (STATIC_LINKING)
   set(CMAKE_LINK_SEARCH_END_STATIC TRUE)
 endif()
 
+set(FIND_LIBRARY_USE_LIB64_PATHS TRUE)
+
 find_package(LibBcc REQUIRED)
 include_directories(${LIBBCC_INCLUDE_DIRS})
 

cmake/FindLibBcc.cmake

@@ -5,6 +5,8 @@
 #  LIBBCC_INCLUDE_DIRS - the libbcc include directory
 #  LIBBCC_LIBRARIES - Link these to use libbcc
 #  LIBBCC_DEFINITIONS - Compiler switches required for using libbcc
+#  LIBBPF_LIBRARY_STATIC - libbpf static library (for static compilation)
+#  LIBBCC_LOADER_LIBRARY_STATIC - libbcc helper static library (for static compilation)
 
 if (LIBBCC_LIBRARIES AND LIBBCC_INCLUDE_DIRS)
   set (LibBcc_FIND_QUIETLY TRUE)
@@ -18,6 +20,7 @@ find_path (LIBBCC_INCLUDE_DIRS
     /usr/include/bcc
     /usr/local/include
     /usr/local/include/libbcc
+    /usr/local/include/bcc
     /opt/local/include
     /opt/local/include/libbcc
     /sw/include
@@ -35,6 +38,28 @@ find_library (LIBBCC_LIBRARIES
     ENV LIBRARY_PATH
     ENV LD_LIBRARY_PATH)
 
+find_library (LIBBPF_LIBRARY_STATIC
+  NAMES
+    bpf
+  PATHS
+    /usr/lib
+    /usr/local/lib
+    /opt/local/lib
+    /sw/lib
+    ENV LIBRARY_PATH
+    ENV LD_LIBRARY_PATH)
+
+find_library (LIBBCC_LOADER_LIBRARY_STATIC
+  NAMES
+    bcc-loader-static
+  PATHS
+    /usr/lib
+    /usr/local/lib
+    /opt/local/lib
+    /sw/lib
+    ENV LIBRARY_PATH
+    ENV LD_LIBRARY_PATH)
+
 include (FindPackageHandleStandardArgs)
 
 

docker/Dockerfile.alpine

@@ -4,6 +4,7 @@ RUN apk add --update \
   build-base \
   clang-dev \
   clang-static \
+  curl \
   cmake \
   elfutils-dev \
   flex-dev \
@@ -11,13 +12,28 @@ RUN apk add --update \
   linux-headers \
   llvm5-dev \
   llvm5-static \
-  zlib-dev \
-  bcc-dev
+  python \
+  zlib-dev
 
 # Put LLVM directories where CMake expects them to be
 RUN ln -s /usr/lib/cmake/llvm5 /usr/lib/cmake/llvm
 RUN ln -s /usr/include/llvm5/llvm /usr/include/llvm
 RUN ln -s /usr/include/llvm5/llvm-c /usr/include/llvm-c
 
+# Alpine currently does not have a package for bcc. Until they do,
+# we'll peg the alpine build to bcc v0.8.0
+#
+# We're building here so docker can cache the build layer
+WORKDIR /
+RUN curl -L https://github.com/iovisor/bcc/archive/v0.8.0.tar.gz \
+  --output /bcc.tar.gz
+RUN tar xvf /bcc.tar.gz
+RUN mv bcc-0.8.0 bcc
+RUN cd /bcc && mkdir build && cd build && cmake .. && make install -j4 && \
+  cp src/cc/libbcc.a /usr/local/lib64/libbcc.a && \
+  cp src/cc/libbcc-loader-static.a /usr/local/lib64/libbcc-loader-static.a && \
+  cp src/cc/libbpf.a /usr/local/lib64/libbpf.a
+
+
 COPY build.sh /build.sh
 ENTRYPOINT ["/bin/sh", "/build.sh"]

docker/build.sh

@@ -5,6 +5,7 @@ set -e
 STATIC_LINKING=${STATIC_LINKING:-OFF}
 RUN_TESTS=${RUN_TESTS:-1}
 
+# Build bpftrace
 mkdir -p "$1"
 cd "$1"
 cmake -DCMAKE_BUILD_TYPE="$2" -DSTATIC_LINKING:BOOL=$STATIC_LINKING ../

src/CMakeLists.txt

@@ -20,7 +20,13 @@ if(HAVE_NAME_TO_HANDLE_AT)
 endif(HAVE_NAME_TO_HANDLE_AT)
 target_link_libraries(bpftrace arch ast parser resources)
 
-target_link_libraries(bpftrace ${LIBBCC_LIBRARIES})
+if (STATIC_LINKING)
+  target_link_libraries(bpftrace ${LIBBCC_LIBRARIES})
+  target_link_libraries(bpftrace ${LIBBPF_LIBRARY_STATIC})
+  target_link_libraries(bpftrace ${LIBBCC_LOADER_LIBRARY_STATIC})
+else()
+  target_link_libraries(bpftrace ${LIBBCC_LIBRARIES})
+endif()
 target_link_libraries(bpftrace ${LIBELF_LIBRARIES})
 
 install(TARGETS bpftrace DESTINATION bin)

tests/CMakeLists.txt

@@ -33,7 +33,13 @@ if(HAVE_NAME_TO_HANDLE_AT)
 endif(HAVE_NAME_TO_HANDLE_AT)
 target_link_libraries(bpftrace_test arch ast parser resources)
 
-target_link_libraries(bpftrace_test ${LIBBCC_LIBRARIES})
+if (STATIC_LINKING)
+  target_link_libraries(bpftrace_test ${LIBBCC_LIBRARIES})
+  target_link_libraries(bpftrace_test ${LIBBPF_LIBRARY_STATIC})
+  target_link_libraries(bpftrace_test ${LIBBCC_LOADER_LIBRARY_STATIC})
+else()
+  target_link_libraries(bpftrace_test ${LIBBCC_LIBRARIES})
+endif()
 target_link_libraries(bpftrace_test ${LIBELF_LIBRARIES})
 
 find_package(Threads REQUIRED)