// Aula 5 - Trabalhando com Alertas

# systemctl stop node_exporter

up == 0

# systemctl start node_exporter

# vim /etc/prometheus/prometheus.yml

global:
  scrape_interval: 10s
  evaluation_interval: 10s
  
rule_files:
 - rules.yml
alerting:
  alertmanagers:
  - static_configs:
    - targets:
       - localhost:9093

# vim /etc/prometheus/rules.yml

groups:
 - name: teste
   rules:
   - alert: InstanceDown
     expr: up == 0
     for: 1m

# useradd --no-create-home --shell /bin/false alertmanager
# mkdir /etc/alertmanager
# mkdir /etc/alertmanager/template
# mkdir -p /var/lib/alertmanager/data

https://prometheus.io/download/

# wget https://github.com/prometheus/alertmanager/releases/download/v0.25.0/alertmanager-0.25.0.linux-amd64.tar.gz

# tar -xzf alertmanager-*.linux-amd64.tar.gz

# cd alertmanager-*.linux-amd64/

# ls alertmanager-*.linux-amd64/

# cp alertmanager-*.linux-amd64/alertmanager /usr/local/bin/

# cp alertmanager-*.linux-amd64/amtool /usr/local/bin/

# cp alertmanager-*.linux-amd64/alertmanager.yml /etc/alertmanager/alertmanager.yml

# chown -R alertmanager:alertmanager /etc/alertmanager

# chown -R alertmanager:alertmanager /var/lib/alertmanager

# chown alertmanager:alertmanager /usr/local/bin/alertmanager

# chown alertmanager:alertmanager /usr/local/bin/amtool

# alertmanager --config.file /etc/alertmanager/alertmanager.yml

# firewall-cmd --add-port=9093/tcp --permanent

# firewall-cmd --reload 

E entre na página web:

http://<server-IP>:9093

# touch /etc/systemd/system/alertmanager.service

# cat > /etc/systemd/system/alertmanager.service << 'EOL'
[Unit]
Description=Alertmanager Service by Prometheus
Wants=network-online.target
After=network.target

[Service]
User=alertmanager
Group=alertmanager
Type=simple
ExecStart=/usr/local/bin/alertmanager \
    --config.file /etc/alertmanager/alertmanager.yml \
    --storage.path /var/lib/alertmanager/data
Restart=always

[Install]
WantedBy=multi-user.target
EOL

# systemctl daemon-reload

# systemctl enable --now alertmanager

# systemctl status alertmanager

# ss -altnp | grep 9093

# vim /etc/alertmanager/alertmanager.yml

global:
  smtp_smarthost: 'smtp.mail.yahoo.com:587'
  smtp_from: 'vitor.mazuco@yahoo.com.br'
  smtp_auth_identity: 'vitor.mazuco@yahoo.com.br'
  smtp_require_tls: true

templates:
- '/etc/alertmanager/template/*.tmpl'

route:
  repeat_interval: 12h
  receiver: enviar-email

receivers:
- name: 'enviar-email'
  email_configs:
  - to: 'vitor.mazuco@yahoo.com.br'
    auth_username: 'vitor.mazuco@yahoo.com.br'
    auth_password: 'kglostyyooiuedcl'
    send_resolved: true

inhibit_rules:
  - source_match:
      severity: 'critical'
    target_match:
      severity: 'warning'
    equal: ['alertname', 'dev', 'instance']
    
# systemctl restart alertmanager

# systemctl restart prometheus

# systemctl stop node_exporter