[root@asimov ~]#rpm -ivh http://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm
Retrieving http://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm
warning: /var/tmp/rpm-tmp.JkMpgZ: Header V4 RSA/SHA1 Signature, key ID 7bd9bf62: NOKEY
Preparing...                          ################################# [100%]
Updating / installing...
   1:nginx-release-centos-7-0.el7.ngx ################################# [100%]
[root@asimov ~]#yum install nginx
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-
              : manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
code                                                     | 2.9 kB     00:00
docker-ce-stable                                         | 3.5 kB     00:00
google-chrome                                            | 1.3 kB     00:00
nginx                                                    | 2.9 kB     00:00
file:///mnt/repodata/repomd.xml: [Errno 14] curl#37 - "Couldn't open file /mnt/repodata/repomd.xml"
Trying other mirror.
(1/4): google-chrome/primary                               | 1.7 kB   00:00
(2/4): docker-ce-stable/x86_64/primary_db                  |  28 kB   00:00
(3/4): code/primary_db                                     |  89 kB   00:00
(4/4): nginx/x86_64/primary_db                             |  46 kB   00:02
google-chrome                                                               3/3
Resolving Dependencies
--> Running transaction check
---> Package nginx.x86_64 1:1.16.0-1.el7.ngx will be installed
--> Processing Dependency: libcrypto.so.10(OPENSSL_1.0.2)(64bit) for package: 1:nginx-1.16.0-1.el7.ngx.x86_64
--> Finished Dependency Resolution
Error: Package: 1:nginx-1.16.0-1.el7.ngx.x86_64 (nginx)
           Requires: libcrypto.so.10(OPENSSL_1.0.2)(64bit)
 You could try using --skip-broken to work around the problem
 You could try running: rpm -Va --nofiles --nodigest

问题1： Requires: libcrypto.so.10(OPENSSL_1.0.2)(64bit)
解决：
##查看yum 源

[root@asimov /etc/yum.repos.d]#vim  nginx.repo
# nginx.repo
[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/centos/7/$basearch/
gpgcheck=0
enabled=1

##找这个包libcrypto.so.10

[root@asimov ~]#find  / -name libcrypto.so.10
find: ‘/run/user/1000/gvfs’: Permission denied
/usr/lib64/libcrypto.so.10  ##有这个东西
[root@asimov ~]#openssl version ##查看openssl版本
OpenSSL 1.0.2o  27 Mar 2018
[root@asimov ~]#rpm -q --provides openssl
openssl = 1:1.0.1e-60.el7
openssl(x86-64) = 1:1.0.1e-60.el7

##查看当前库文件中的 libcrypto.so.10

[root@asimov ~]#rpm -q --provides openssl-libs | grep libcrypto.so.10
libcrypto.so.10()(64bit)
libcrypto.so.10(OPENSSL_1.0.1)(64bit)
libcrypto.so.10(OPENSSL_1.0.1_EC)(64bit)##libcrypto.so.10(OPENSSL_1.0.2)(64bit)
libcrypto.so.10(libcrypto.so.10)(64bit)

##升级OpenSSL 1.0.2
http://rpmfind.net/linux/rpm2html/search.php?query=libcrypto.so.10(OPENSSL_1.0.2)(64bit)&submit=Search+…&system=&arch=
##右下角

[root@asimov /home/kiosk/repod]#rpm -ivh openssl-libs-1.0.2k-16.el7.x86_64.rpm

问题：和之前版本的冲突
file /usr/lib64/openssl/engines/libubsec.so from install of openssl-libs-1:1.0.2k-16.el7.x86_64 conflicts with file from package openssl-libs-1:1.0.1e-60.el7.x86_64
解决：强制安装（最好别强制安装，实在不行就强制安装）

[root@asimov /home/kiosk/repod]#rpm -ivh openssl-libs-1.0.2k-16.el7.x86_64.rpm --force
warning: openssl-libs-1.0.2k-16.el7.x86_64.rpm: Header V3 RSA/SHA256 Signature, key ID f4a80eb5: NOKEY
Preparing...                          ################################# [100%]
Updating / installing...
   1:openssl-libs-1:1.0.2k-16.el7     ################################# [100%]

##继续用yum 安装

  [root@asimov ~]#yum install  nginx
    There was a problem importing one of the Python modules
    required to run yum. The error leading to this problem was:
    
       /home/kiosk/anaconda3/envs/python36/lib/liblzma.so.5:
        version `XZ_5.1.2alpha' not found (required by /lib64/librpmio.so.3)

问题：liblzma.so.5找不到’xz_5.1.2alpha’版本

[root@asimov ~]#rpm -q --provides openssl  ##rpm貌似也用不了了
rpm: /home/kiosk/anaconda3/envs/python36/lib/liblzma.so.5:
 version `XZ_5.1.2alpha' not found (required by /lib64/librpmio.so.3)



[root@asimov ~]#find  / -name liblzma.so.5   
find: ‘/run/user/1000/gvfs’: Permission denied
/usr/lib64/liblzma.so.5
/home/kiosk/anaconda3/pkgs/xz-5.2.4-h14c3975_4/lib/liblzma.so.5
/home/kiosk/anaconda3/lib/liblzma.so.5
/home/kiosk/anaconda3/envs/python3/lib/liblzma.so.5
/home/kiosk/anaconda3/envs/python36/lib/liblzma.so.5
/home/kiosk/anaconda3/envs/flask/lib/liblzma.so.5
/home/kiosk/anaconda3/envs/Scrapy/lib/liblzma.so.5
/home/kiosk/anaconda3/envs/Django/lib/liblzma.so.5

解决：
https://www.cnblogs.com/Lee-yl/p/9748699.html
可能原因是 librpmio.so.3 需要 XZ_5.1.2alpha 在lzma共享库中定义符号的库。liblzma.so.5.2.2定义此符号，但liblzma.so.5.2.3、liblzma.so.5.2.4等版本不定义。

[root@asimov ~]#find  / -name liblzma.so.5.2.2
find: ‘/run/user/1000/gvfs’: Permission denied
/usr/lib64/liblzma.so.5.2.2

##所以说liblzma.so.5这个库需要liblzma.so.5.2.2定义此符号，然后把liblzma.so.5.2.2软链接/liblzma.so.5库下

[root@asimov ~]#ln -s -f /usr/lib64/liblzma.so.5.2.2
  /home/kiosk/anaconda3/envs/python36/lib/liblzma.so.5

[root@asimov ~]#yum  install  nginx
Loaded plugins: langpacks, product-id, search-disabled-repos, subscription-
              : manager
This system is not registered to Red Hat Subscription Management. You can use subscription-manager to register.
Resolving Dependencies
--> Running transaction check
---> Package nginx.x86_64 1:1.16.0-1.el7.ngx will be installed
--> Finished Dependency Resolution

Dependencies Resolved

================================================================================
 Package       Arch           Version                       Repository     Size
================================================================================
Installing:
 nginx         x86_64         1:1.16.0-1.el7.ngx            nginx         766 k

Transaction Summary
================================================================================
Install  1 Package
..........................
----------------------------------------------------------------------
  Verifying  : 1:nginx-1.16.0-1.el7.ngx.x86_64                              1/1

Installed:
  nginx.x86_64 1:1.16.0-1.el7.ngx

[root@asimov ~]#rpm --help ##rpm也可以用了

Usage: rpm [OPTION...]

Query/Verify package selection options:
  -a, --all                        query/verify all packages
  -f, --file                       query/verify package(s) owning file