如何用Bazel构建uWSGI？关于构建规则选择的疑问

因为uWSGI的构建是先通过Python脚本处理配置生成编译所需文件，再编译C代码，所以不能直接用单一的cc_binary或py_binary，需要结合genrule串联配置生成与编译流程，以下是具体实现步骤：

1. 完善WORKSPACE中uWSGI仓库的BUILD定义 #

补全new_git_repository的build_file_content，暴露uWSGI的源码、配置脚本和默认配置目录：

load("@bazel_tools//tools/build_defs/repo:git.bzl", "new_git_repository")

new_git_repository(
    name = "uwsgi",
    remote = "git@github.com:unbit/uwsgi.git",
    commit = "ca8bc6acc98b2c062b5b00668acd851e210fcbca",
    build_file_content = """
filegroup(
    name = "sources",
    srcs = glob(["**/*.c", "**/*.h"]),
    visibility = ["//visibility:public"],
)

py_binary(
    name = "uwsgiconfig",
    srcs = ["uwsgiconfig.py"],
    visibility = ["//visibility:public"],
)

filegroup(
    name = "buildconf",
    srcs = glob(["buildconf/*.ini"]),
    visibility = ["//visibility:public"],
)
""",
)

2. 项目中编写BUILD规则处理自定义配置并构建uWSGI #

假设自定义配置myconf.ini放在项目根目录，创建BUILD.bazel文件，按流程实现配置复制、编译文件生成、最终二进制编译：

# 复制自定义配置到uWSGI的buildconf目录（模拟手动复制操作）
genrule(
    name = "prepare_uwsgi_config",
    srcs = [
        "@uwsgi//:buildconf",
        "myconf.ini",
    ],
    outs = ["uwsgi_buildconf/myconf.ini"],
    cmd = """
        mkdir -p $(@D)/uwsgi_buildconf
        cp $(location myconf.ini) $(@D)/uwsgi_buildconf/
        # 按需复制uWSGI默认配置
        cp $(locations @uwsgi//:buildconf) $(@D)/uwsgi_buildconf/
    """,
)

# 执行uwsgiconfig.py生成编译所需的Makefile和头文件
genrule(
    name = "generate_uwsgi_build_files",
    srcs = [
        "@uwsgi//:sources",
        "@uwsgi//:uwsgiconfig",
        ":prepare_uwsgi_config",
    ],
    outs = [
        "uwsgi_build/uwsgi.h",
        "uwsgi_build/Makefile",
    ],
    cmd = """
        mkdir -p $(@D)/uwsgi_build
        # 切换到uWSGI源码目录执行配置脚本
        cd $(@D)/../external/uwsgi
        PYTHONPATH=. python $(location @uwsgi//:uwsgiconfig) --build myconf \
            --confdir $(location :prepare_uwsgi_config)/../uwsgi_buildconf
        # 将生成的文件复制到Bazel输出目录
        cp uwsgi.h $(@D)/uwsgi_build/
        cp Makefile $(@D)/uwsgi_build/
        cp *.c $(@D)/uwsgi_build/
    """,
)

# 编译生成最终的uWSGI二进制
cc_binary(
    name = "uwsgi",
    srcs = [
        "@uwsgi//:sources",
        ":generate_uwsgi_build_files",
    ],
    includes = ["uwsgi_build"],
    # 根据配置需求添加依赖库链接选项
    linkopts = [
        "-lpthread",
        "-lz",
        "-ldl",
    ],
)

3. 关键说明 #

• genrule用于模拟手动操作流程：第一个负责配置文件复制，第二个调用Python脚本生成编译资源。
• 沙盒环境中需用$(location)获取文件绝对路径，确保脚本能正确找到依赖文件。
• 链接选项需根据你的uWSGI配置调整，比如启用Python支持时需添加Python库链接参数。

内容的提问来源于stack exchange，提问作者legend855