在使用rpm方式安装rabbitmq时，执行yum install rabbitmq-server-3.7.18-1.el7.noarch.rpm出现以下问题：
yum install rabbitmq-server-3.7.18-1.el7.noarch.rpm
Loaded plugins: fastestmirror
Examining rabbitmq-server-3.7.18-1.el7.noarch.rpm: rabbitmq-server-3.7.18-1.el7.noarch
Marking rabbitmq-server-3.7.18-1.el7.noarch.rpm to be installed
Resolving Dependencies
--> Running transaction check
---> Package rabbitmq-server.noarch 0:3.7.18-1.el7 will be installed
--> Processing Dependency: erlang >= 20.3 for package: rabbitmq-server-3.7.18-1.el7.noarch
Loading mirror speeds from cached hostfile
--> Finished Dependency Resolution
Error: Package: rabbitmq-server-3.7.18-1.el7.noarch (/rabbitmq-server-3.7.18-1.el7.noarch)
Requires: erlang >= 20.3
Available: erlang-R16B-03.18.el7.x86_64 (epel)
erlang = R16B-03.18.el7
You could try using --skip-broken to work around the problem
You could try running: rpm -Va --nofiles --nodigest
通过erl查看，发现已经安装了21.0的erl，这时需要重新安装最新的erlang
1.手动配置erlang的repo源
vi /etc/yum.repos.d/rabbitmq-erlang.repo
在文件中加入以下内容：
# In /etc/yum.repos.d/rabbitmq-erlang.repo
[rabbitmq-erlang]
name=rabbitmq-erlang
baseurl=https://dl.bintray.com/rabbitmq/rpm/erlang/20/el/7
gpgcheck=1
gpgkey=https://dl.bintray.com/rabbitmq/Keys/rabbitmq-release-signing-key.asc
repo_gpgcheck=0
enabled=1
2.清理rpm文件缓存
yum clean all
yum makecache
3.查看已有的源文件
yum list |grep erlang 此时发现有一个21.3的文件可以用，我们就安装这个文件
yum install erlang.x86_64
完成后继续执行yum install rabbitmq-server-3.7.18-1.el7.noarch.rpm提示成功
