CentOS配置Zmqpp

踩坑无数，废了好几个container，特此记录一下
Centos命令行起始是#，但因为#在代码片里会注释化，就改成$了

1. 预先安装dependency

$ yum install -y wget gcc-c++ automake autoconf libtool make lsof vim nano boost git
$ yum -y install openssl-devel bzip2-devel expat-devel gdbm-devel curl-devel boost-devel readline-devel sqlite-devel kernel-devel 

安装时遇到过GPG Keys Failed的错误

GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
Public key for perl-threads-2.21-2.el8.x86_64.rpm is not installed. Failing package is: perl-threads-1:2.21-2.el8.x86_64
GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
Public key for perl-threads-shared-1.58-2.el8.x86_64.rpm is not installed. Failing package is: perl-threads-shared-1.58-2.el8.x86_64
GPG Keys are configured as: file:///etc/pki/rpm-gpg/RPM-GPG-KEY-centosofficial
The downloaded packages were saved in cache until the next successful transaction.
You can remove cached packages by executing 'dnf clean packages'.
Error: GPG check FAILED

因为用的是docker，于是删了容器重新开个容器就好了
解决问题的过程中搜到过一个可以尝试的方案，在我的电脑上没有用，不过或许可以帮到大家

2. 按照官方指令下载三个包

$ git clone git://github.com/jedisct1/libsodium.git
$ git clone git://github.com/zeromq/libzmq.git
$ git clone git://github.com/zeromq/zmqpp.git

3. Build libsodium，这个没有什么问题

$ cd libsodium
$ ./autogen.sh
$ ./configure && make check
$ make install     // 我用的是docker container所以不需要sudo，没有权限的话要加上
$ ldconfig           // 我用的是docker container所以不需要sudo，没有权限的话要加上

4. Build libzmq

$ cd libzmq
$ ./autogen.sh

这里如果直接跑 ./configure --with-libsodium && make 可能会遇到找不到libsodium的问题

$ ./configure --with-libsodium && make 
............
checking for working volatile... yes
checking for sodium... no
./configure: line 421: test: then: integer expression expected
configure: error: run
./configure: line 310: return: then: numeric argument required
./configure: line 320: exit: then: numeric argument required

猜想是因为调用时无法查看到 libsodium 动态库的地址，于是查看

$ whereis libsodium
libsodium: /usr/local/lib/libsodium.so /usr/local/lib/libsodium.a /usr/local/lib/libsodium.la /usr/src/zmq/libsodium

果然，libsodium 并不在默认会查找的 /usr/lib 和 /lib 中，于是添加动态库地址并查看

$ echo "/usr/local/lib">>/etc/ld.so.conf
$ cat /etc/ld.so.conf
include ld.so.conf.d/*.conf
/usr/local/lib

然后就可以继续了

$ ./configure --with-libsodium && make
$ make install     // 我用的是docker container所以不需要sudo，没有权限的话要加上
$ ldconfig           // 我用的是docker container所以不需要sudo，没有权限的话要加上

5. Build zmqpp

记得 libzmq 的动态库地址也要include进 /etc/ld.so.conf

$ cd zmqpp
$ make
$ make check
$ sudo make install
$ make installcheck

6. 编译

取了官方simple_client和simple_server例子，想着终于装好了可以跑了，结果

$ g++ -o server server.cpp -lzmq
/tmp/ccOYmpjR.o: In function `main':
server.cpp:(.text+0x74): undefined reference to `zmqpp::socket::socket(zmqpp::context const&, zmqpp::socket_type)'
server.cpp:(.text+0x8a): undefined reference to `zmqpp::socket::bind(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)'
server.cpp:(.text+0x99): undefined reference to `zmqpp::message::message()'
server.cpp:(.text+0xb7): undefined reference to `zmqpp::socket::receive(zmqpp::message&, bool)'
server.cpp:(.text+0x15d): undefined reference to `zmqpp::socket::send(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool)'
server.cpp:(.text+0x193): undefined reference to `zmqpp::message::~message()'
server.cpp:(.text+0x1fa): undefined reference to `zmqpp::message::~message()'
server.cpp:(.text+0x20e): undefined reference to `zmqpp::socket::~socket()'
/tmp/ccOYmpjR.o: In function `zmqpp::context::~context()':
server.cpp:(.text._ZN5zmqpp7contextD2Ev[_ZN5zmqpp7contextD5Ev]+0x20): undefined reference to `zmqpp::context::terminate()'
/tmp/ccOYmpjR.o: In function `zmqpp::message& zmqpp::message::operator>><std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&)':
server.cpp:(.text._ZN5zmqpp7messagersINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEERS0_RT_[_ZN5zmqpp7messagersINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEEEERS0_RT_]+0x33): undefined reference to `zmqpp::message::get(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >&, unsigned long) const'
collect2: error: ld returned 1 exit status

看出来了是找不到library，但到底是怎么个找不到法我思考了很久，终于找到了正确的写法

$ g++ -o server server.cpp /usr/local/lib/libzmqpp.a -lzmq

不可以少任何一项，也不可以把静态library放到前面写，直接引入-L和 pkg-config 也不管用，很奇怪
不过终于是真的好了

$ ./client 
Connecting to hello world server…
Sending Hello 0…
Received World 0
Sending Hello 1…
Received World 1
Sending Hello 2…
Received World 2
Sending Hello 3…
Received World 3
Sending Hello 4…
Received World 4

$ ./server
Received Hello
Received Hello
Received Hello
Received Hello
Received Hello