To address the risks associated with expired SSL/TLS certificates, organizations should implement several proactive strategies:

- Automated Monitoring Tools: Deploy tools that continuously monitor the status of SSL/TLS certificates and send alerts when they are approaching expiration. This helps prevent service disruptions caused by unnoticed expired certificates.

- Emergency Renewal Procedures: Establish clear emergency procedures for rapid certificate renewal in case of unexpected expiration. This ensures minimal downtime and protects against potential security risks.

- Regular Audits: Conduct regular audits of your SSL/TLS certificate inventory to identify and renew any expired certificates promptly. Keeping an up-to-date inventory helps avoid lapses in security.

- Automated Certificate Provisioning: Implement systems that automate the issuance and renewal of SSL/TLS certificates to maintain continuous validity. Tools such as cert-manager in Kubernetes streamline this process.

**Automated Certificate Provisioning in Kubernetes:**

In Kubernetes, you can automate SSL/TLS certificate management using cert-manager. This tool interacts with Certificate Authorities (CAs) like Let’s Encrypt to automatically issue and renew certificates.

- Install cert-manager:

```bash
kubectl apply -f https://github.com/cert-manager/cert-manager/releases/latest/download/cert-manager.yaml
```

Here is a YAML configuration for cert-manager to automate certificate provisioning:

```yaml
apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: example-cert
  namespace: default
spec:
  secretName: example-cert-secret
  issuerRef:
    name: letsencrypt-prod
    kind: ClusterIssuer
  commonName: example.com
  dnsNames:
    - example.com
    - www.example.com
  duration: 90d
  renewBefore: 30d
```

**Monitoring with Certbot:**

For environments not using Kubernetes, you can use Certbot to automate SSL certificate issuance and renewal.

```bash
# Automatically issue or renew SSL certificates using Certbot
domain="example.com"
email="admin@example.com"

# Run Certbot in standalone mode to obtain the certificate
certbot certonly --standalone -d $domain --email $email --agree-tos
```

**Automated Certificate Renewal with Cron Job:**

You can automate the renewal process using a cron job:

```bash
# Edit your crontab with: crontab -e
0 0 * * * /usr/bin/certbot renew --quiet
```

This cron job will run daily at midnight to check for certificates that are due for renewal, ensuring continuous coverage without manual intervention.