How to install datadog agent in centos

$ DD_AGENT_MAJOR_VERSION=7 DD_API_KEY=78ef904b8401f15a458bb59464c6e54f DD_SITE="datadoghq.com" bash -c "$(curl -L https://s3.amazonaws.com/dd-agent/scripts/install_script.sh)"

$ systemctl start datadog-agent
$ systemctl stop datadog-agent
$ systemctl restart datadog-agent
$ systemctl status datadog-agent
$ ls /var/log/datadog/
$ more /etc/datadog-agent/datadog.yaml
$ more /var/log/datadog/agent.log
$ more /var/log/datadog/process-agent.log
$ more /var/log/datadog/trace-agent.log
$ datadog-agent configcheck
$ datadog-agent config
$ datadog-agent health
$ datadog-agent hostname
$ datadog-agent version