Encountered when starting Ubuntu rabbitmq-server 5 Zhong error

erlang version used here is 21.1, openssl version 1.1.0g, RabbitMQ version 3.7.15

1 undef

Error description:
    init:do_boot/3
    init:start_em/1
    rabbit:start_it/1 line 478
    rabbit:'-boot/0-fun-0-'/0 line 329
    rabbit_node_monitor:prepare_cluster_status_files/0 line 106
    rabbit_mnesia:ensure_mnesia_dir/0 line 571
    mnesia:system_info(directory)
error:undef

undef erlang error is not installed or not installed various types of full-reliance

mounting step erlang

In erlang official website to download otp_src_21.1.tar.gz
After importing Ubuntu rz

tar -xvf otp_src_21.1.tar.gz
cd otp_src_21.1
./configure --prefix=/usr/local/erlang21 --with-ssl --enable-threads --enable-smp-support --enable-kernel-poll --enable-hipe --without-javac
make -j 4
make install

Various dependencies

sudo apt-get install build-essential
sudo apt-get install libncurses5-dev
sudo apt-get install libssl-dev
sudo apt-get install m4
sudo apt-get install unixodbc unixodbc-dev
sudo apt-get install xsltproc 
sudo apt-get install fop 
sudo apt-get install tk8.5

2 to find the missing command erl

Solution: modify environment variables

sudo vi /etc/profile

Add a line installation location:

export PATH=$PATH:/usr/local/erlang21/bin

3 cannot connect to host/port

 ERROR: epmd error for host ubuntu-server: address (cannot connect to host/port)

solve:

sudo vi /etc/hosts

Add a line in there

127.0.0.1       ubuntu-server(你的主机名)

4 erlang version is too low

Uninstall: https://blog.csdn.net/wudixiaotie/article/details/84719722
then you follow the above steps to install a new

5 missing_dependencies,[crypto,ssl]

Error description:
    init:do_boot/3
    init:start_em/1
    rabbit:start_it/1 line 478
    rabbit:broker_start/0 line 352
    rabbit_plugins:prepare_plugins/1 line 307
    rabbit_plugins:ensure_dependencies/1 line 282
throw:{error,{missing_dependencies,[crypto,ssl],
                                   [amqp10_client,cowboy,cowlib,rabbitmq_aws,
                                    rabbitmq_management,
                                    rabbitmq_management_agent,rabbitmq_shovel,
                                    rabbitmq_trust_store]}}

First look at whether to install openssl

openssl version

View version look
openssl installation steps

sudo apt-get install openssl

wget http://www.openssl.org/source/openssl-1.1.0g.tar.gz  
tar -zxf openssl-1.1.0g.tar.gz   
cd openssl-1.1.0g 
./config --prefix=/usr/bin/ssl    
sed -i "s|CFLAG= |CFLAG= -fPIC |" Makefile  
make 
make install

Re-installed after installation do erlang21 operation, bring ssl

 ./configure --prefix=/usr/local/erlang21 --with-ssl --enable-threads --enable-smp-support --enable-kernel-poll --enable-hipe --without-javac

Error if installed, do the same operation erlang21 installation, tape ssl
if further errors, may be too low version