背景介绍
参考链接： https://blog.csdn.net/ddxygq/article/details/123437072
DataHub是由LinkedIn的数据团队开源的一款提供元数据搜索与发现的工具。
提到LinkedIn，不得不想到大名鼎鼎的Kafka，Kafka就是LinkedIn开源的。LinkedIn开源的Kafka直接影响了整个实时计算领域的发展，而LinkedIn的数据团队也一直在探索数据治理的问题，不断努力扩展其基础架构，以满足不断增长的大数据生态系统的需求。随着数据的数量和丰富性的增长，数据科学家和工程师要发现可用的数据资产，了解其出处并根据见解采取适当的行动变得越来越具有挑战性。为了帮助增长的同时继续扩大生产力和数据创新，创建了通用的元数据搜索和发现工具DataHub。
Datahub作为新一代的元数据管理平台，大有取代老牌元数据管理工具Atlas之势。首先，阿里云也有一款名为DataHub的产品，是一个流式处理平台，本文所述DataHub与其无关。
市面上常见的元数据管理系统有如下几个：
- a) linkedin datahub: https://github.com/linkedin/datahub
- b) apache atlas: https://github.com/apache/atlas
- c) lyft amundsen https://github.com/lyft/amundsen
笔者之前白嫖了亚马逊的EC2服务器，在链接文章的教程下尝试安装datahub, 系统默认环境python2.7、python3.7；
安装datahub过程
1、笔者尝试安装了 python3.8，本来开始没有安装3.8，但是在安装完datahub的时候，尝试验证版本号时抱如下第一个错误
python3 -m datahub version
DataHub CLI version: 0.10.0.1
Python version: 3.7.16 (default, Dec 15 2022, 23:24:54)
[GCC 7.3.1 20180712 (Red Hat 7.3.1-15)]
Exception ignored in: <generator object configure_logging at 0x7f8fcca5a050>
Traceback (most recent call last):
File "/home/ec2-user/.local/lib/python3.7/site-packages/datahub/utilities/logging_manager.py", line 187, in configure_logging
File "/usr/lib64/python3.7/contextlib.py", line 486, in __exit__
AttributeError: 'NoneType' object has no attribute 'exc_info'2、上边的错误出现后没有找到合适的解决方案，就直接升级python版本到3.8了，以后就有了一系列的坑,如下第二个错误，发生在对python3.8编译的过程中。
wget https://www.python.org/ftp/python/3.8.3/Python-3.8.3.tgz
tar zxvf Python-3.8.3.tgz
./configure --prefix=/usr/lib/python3.8
checking build system type... x86_64-pc-linux-gnu
checking host system type... x86_64-pc-linux-gnu
checking for python3.8... no
checking for python3... python3
checking for --enable-universalsdk... no
checking for --with-universal-archs... no
checking MACHDEP... "linux"
checking for gcc... no
checking for cc... no
checking for cl.exe... no
configure: error: in `/home/ec2-user/Python-3.8.3':
configure: error: no acceptable C compiler found in $PATH
See `config.log' for more details
通过安装 gcc 解决了上边的问题; 因为ec2有权限限制，非root用户执行命令时尽可能带上sudo
sudo yum -y install gcc-c++
sudo make && sudo make install3、然后make install的时候遇到问题三，如下提示，通过安装zlib-devel解决
zipimport.ZipImportError: can't decompress data; zlib not available
sudo yum install zlib-devel
编译完并通过ln -s 命令修改了python3的软链之后，执行pip3的操作开始报如下的错误，通过安装openssl 和 openssl-devel解决，但是还得从新编译python3.8，从.config开始从新执行之前的命令
python3 -m pip install --upgrade pip wheel setuptools
WARNING: pip is configured with locations that require TLS/SSL, however the ssl module in Python is not available.
WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/pip/
WARNING: Retrying (Retry(total=3, connect=None, read=None, redirect=None, status=None)) after connection broken by 'SSLError("Can't connect to HTTPS URL because the SSL module is not available.")': /simple/pip/ sudo yum -y install openssl openssl-devel
python3 -m pip install --upgrade acryl-datahub4、之后再次执行datahub的安装，入到如下问题, 通过安装 libffi-devel 解决
File "/usr/lib/python3.8/lib/python3.8/ctypes/__init__.py", line 7, in
from _ctypes import Union, Structure, Array
ModuleNotFoundError: No module named '_ctypes'
[end of output]
note: This error originates from a subprocess, and is likely not a problem with pip.
ERROR: Failed building wheel for avro
File "/usr/lib/python3.8/lib/python3.8/ctypes/__init__.py", line 7, in
from _ctypes import Union, Structure, Array
ModuleNotFoundError: No module named '_ctypes'
[end of output]
note: This error originates from a subprocess, and is likely not a problem with pip.
ERROR: Failed building wheel for click-default-group
sudo yum install libffi-devel5、继续执行datahub的安装，遇到如下问题, 通过安装bzip2-devel 同时从新编译解决(如果不从新编译还会报错)
File "/usr/lib/python3.8/lib/python3.8/bz2.py", line 19, in
from _bz2 import BZ2Compressor, BZ2Decompressor
ModuleNotFoundError: No module named '_bz2' sudo yum install bzip2-devel
sudo make && sudo make install直到此时解决以上的问题，才算是把datahub安装好了。
启动datahub
6、如果docker服务没有启动会可能有如下问题；启动服务失败，报标题中的错误，试试启动服务命令前加上 sudo。
The name org.freedesktop.PolicyKit1 was not provided by any .service files See system logs and 'systemctl status docker.service' for details.7、docker出现的问题如下
ERROR: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get "http://%2Fvar%2Frun%2Fdocker.sock/v1.24/info": dial unix /var/run/docker.sock: connect: permission denied通过修改docker 组来处理
Try adding your user to the docker group:
Run usermod -aG docker "${USER}", then
either log out and log back in, or run newgrp docker.
After this you have to restart your docker daemon: sudo service docker restart.到现在所有的坑基本上踩完了，直接执行如下启动datahub的命令并得到如下提示，GAME OVER!
python3 -m datahub docker quickstart
Total Docker memory configured 0.96GB is below the minimum threshold 3.8GB. You can increase the memory allocated to Docker in the Docker settings.是的，这是一次全程失败的实验过程，但是笔者认为除了最后设备硬件不够用之外，主要的安装踩坑过程基本上就差不多了。
