Consul Installation on CentOS

To install Consul on CentOS 8.2, first add the HashiCorp repository:

yum install -y yum-utils
yum-config-manager --add-repo https://rpm.releases.hashicorp.com/RHEL/hashicorp.repo
yum -y install consul

Service Cofniguration

Create or modify the systemd service file at /etc/systemd/system/consul.service:

[Unit]
Description="HashiCorp Consul Service Mesh"
Documentation=https://www.consul.io/
Requires=network-online.target
After=network-online.target
ConditionFileNotEmpty=/etc/consul.d/consul.hcl

[Service]
EnvironmentFile=/etc/consul.d/consul.env
User=root
Group=root
ExecStart=/usr/bin/consul agent -config-dir=/etc/consul.d/
ExecReload=/bin/kill -HUP $MAINPID
Restart=on-failure
LimitNOFILE=65536

[Install]
WantedBy=multi-user.target

Consul Server Configuration

Create a JSON configuration file at /etc/consul.d/server_config.json:

{
  "datacenter": "primary-dc",
  "data_dir": "/var/lib/consul",
  "log_level": "INFO",
  "node_name": "server-node",
  "server": true,
  "ports": {
    "http": 8500,
    "dns": 8600,
    "serf_lan": 8001,
    "serf_wan": 8002,
    "server": 8003
  }
}

Modify /etc/consul.d/consul.hcl with these settings:

client_addr = "0.0.0.0"
ui_config {
  enabled = true
}
bind_addr = "0.0.0.0"
advertise_addr = "127.0.0.1"
bootstrap_expect = 1

Spring Boot Integration

For Spring Boot integration, add these dependencies to your pom.xml:

<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-consul-config</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.cloud</groupId>
  <artifactId>spring-cloud-starter-consul-discovery</artifactId>
</dependency>
<dependency>
  <groupId>org.springframework.boot</groupId>
  <artifactId>spring-boot-starter-actuator</artifactId>
</dependency>

Configure bootstrap.yml:

spring:
  cloud:
    consul:
      host: YOUR_SERVER_IP
      port: 8500
      discovery:
        health-check-path: /actuator/health
        health-check-interval: 5s
        instance-id: ${spring.application.name}:${server.port}