Detailed explanation of how to use Nginx + consul + upsync to achieve dynamic load balancing

### Time to connect to the upstream server proxy_connect_timeout 1s;
		### Send request timeout proxy_send_timeout 1s;
		### Accept the corresponding timeout proxy_read_timeout 1s;

# Basic commands # Install the netstat command yum install netstat
 # View all TCP port usage netstat -ntlp
 # View the current service process ps -ef Optional: [ | grep nginx]
 # Force kill the program corresponding to the port kill -9 pid process number # Configure yum source yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum update
yum install -y yum-utils device-mapper-persistent-data lvm2
# Install the basic environment yum install gcc-c++
yum install -y pcre pcre-devel
yum install -y zlib zlib-devel
yum install -y openssl openssl-devel
yum install wget
yum install unzip

# Download its installation package, the -c in wget -c means breakpoint continuation wget -c https://releases.hashicorp.com/consul/1.8.5/consul_1.8.5_linux_amd64.zip
# Unzip the compressed package upzip unzip consul_1.8.5_linux_amd64.zip
# Execute the ./consul command. If the line Usage: consul [--version] [--help] <command> [<args>] and the following parameters appear, it means that there is no problem with this consul./consul
# Turn off the firewall systemctl stop firewalld
# Start consul, fill in the IP address of your computer, if it is a virtual machine, fill in the IP address of the virtual machine, centos can use ip addr to view the IP address, window to view the IP address with ipconfig
./consul agent -dev -ui -node=consul-dev -client=192.168.254.134
# Of course, you can also use the background running method, so that the output log returns to the nohup.out file at the same level nohup ./consul agent -dev -ui -node=consul-dev -client=192.168.254.134 &
# Access consul's web page 192.168.254.134:8500

# Check and close the background process of consul. The 19854 I wrote here is the process pid queried by jobs -l
jobs -l
kill -9 19854

# Download the upsync module and unzip it wget -c https://github.com/weibocom/nginx-upsync-module/archive/master.zip
unzip nginx-upsync-module-master.zip
# Download nginx
wget -c http://nginx.org/download/nginx-1.9.9.tar.gz
# Unzip to the current directory tar -zxvf nginx-1.9.9.tar.gz
# Configure an nginx user and user group. -s /sbin/nologin nginx means that the user cannot log in to the host. groupadd nginx
useradd -g nginx -s /sbin/nologin nginx
# These two folders will be specified when compiling nginx mkdir -p /var/tmp/nginx/client/
mkdir -p /usr/local/nginx
# Enter the directory of the unzipped folder of nginx cd nginx-1.9.9 
# Compile nginx, --prefix represents the directory where nginx is installed. : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : : :
make && make install
## Enter the directory where nginx was just installed, that is, the /usr/local/nginx directory, and enter the conf directory to edit the file contents of the conf directory upstream myserver {
 server 127.0.0.1:11111;# This is fixed, ignore it# springbootserver: key value, upsync_timeout timeout 3 seconds, upsync_interval interval, upsync_type type consul, strong_dependency enhanced dependency upsync 192.168.254.134:8500/v1/kv/upstreams/springbootserver upsync_timeout=3000ms upsync_interval=500ms upsync_type=consul strong_dependency=off;
 #Put the pulled configuration file in the following configured directory upsync_dump_path /usr/local/nginx-1.9.9/conf/upsync_dump.conf;

 }
 #Specify the location in server as the upstream server just created
 location / {
 proxy_pass http://myserver;
 index index.html index.htm;
 }
# Enter the sbin directory and start nginx
./nginx

# Use curl request, it must be a put request curl -X PUT http://192.168.254.134:8500/v1/kv/upstreams/springbootserver/192.168.0.116:8080

curl -X PUT http://192.168.254.134:8500/v1/kv/upstreams/springbootserver/192.168.0.116:8081

#Or use postman to call the API provided by consul to add key and value
http://192.168.254.134:8500/v1/kv/upstreams/springbootserver/192.168.0.116:8081

# You can even use the graphical interface to manually add key values. When adding manually, please note that if you are creating a folder, you need to add a forward slash at the end: /

{"weight":1, "max_fails":2, "fail_timeout":10, "down":0}