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Docker SSL Checker

Check SSL certificates in Docker containers

About Docker SSL Checker

The Docker SSL Configurator generates the TLS configuration for services running inside Docker containers: the certificate directory layout, the volume mount that exposes your certificate to the container, and a compose snippet with the virtual-host variables reverse proxies expect. It cannot see inside your Docker daemon, so instead of pretending to scan containers it produces configuration derived from the domain you enter, ready to paste into your setup.

Use Cases

  • •Verify TLS configuration in Docker Compose deployments
  • •Check certificate expiry for containerized web services
  • •Audit cipher strength in Docker Swarm or Kubernetes
  • •Ensure reverse proxy containers have valid SSL

How to Use

  • •Enter the domain or IP of your Docker container service
  • •Click "Run" to start the SSL analysis
  • •Review TLS version support, cipher strength, and certificate details

Frequently Asked Questions

Simply enter the domain or IP address where your Docker container is serving HTTPS traffic. The checker will analyze the SSL/TLS configuration, including certificate validity, cipher strength, and protocol support for the containerized service.
Containerized applications are often exposed directly to the internet through reverse proxies or ingress controllers. Misconfigured TLS can leave your containers vulnerable to man-in-the-middle attacks, protocol downgrades, and data interception.
Modern security best practices recommend supporting TLS 1.2 and TLS 1.3 while disabling TLS 1.0, TLS 1.1, and all SSL versions. TLS 1.3 offers improved performance and security, making it ideal for containerized microservices.
No, and any page claiming to would be misleading. Your Docker daemon is reachable only from your own infrastructure, so nothing on the public internet — this site included — can list your containers or read their certificates. What this page does instead is generate the configuration that gets certificates into containers correctly, which is the part of the problem solvable from here.
From your usual issuance process: certbot on the host, an internal authority, or copied from wherever they are issued. The configurator only fixes the layout and the mount; the files themselves must be valid and current. Once they are in place, verify the running service with the certificate checker pages rather than trusting the file layout alone.
So a compromised container cannot rewrite the credentials that identify it. The read-only flag costs nothing and removes a whole class of persistence for an attacker who gains file access inside the container. The host side stays writable by your renewal process, which is the only writer the layout needs.
They tell reverse-proxy setups which domain a container answers for and which certificate to fetch for it. Without them the proxy serves its default certificate and your visitors get a name-mismatch warning despite everything else being correct. If you run your own proxy rather than an auto-configuring one, translate the same values into its explicit routing configuration.
Renew on the host where the files live, then reload or restart the container so it picks up the replacements. A renewed file on disk changes nothing for a process that read the old one at startup, and this silent staleness is the most common Docker TLS failure. Automate the reload alongside the renewal and confirm afterwards with an external check of what the container actually serves.

What the Configurator Writes

Enter a domain and this page writes the TLS configuration for running it behind Docker: where the certificate lives, how it reaches the container, and the environment variables reverse proxies expect. It generates text from your input — it has no access to your Docker daemon and makes no claim to inspect it.

  1. 1Get the certificate directory and volume mount for your domain, following the per-domain layout so each site's files stay separate on the host and are mounted read-only into the container.
  2. 2Get a compose snippet wiring the mount together with the virtual-host variables that nginx-proxy style setups use to route your domain and pick up its certificate automatically.
  3. 3Place your real certificate files at the generated paths — issued by certbot or your authority of choice — then start the stack and confirm from outside with the scanner pages on this site.

Certificate issuance and renewal still happen the way they always do; this page only writes the configuration that consumes the result. Pair it with the renewal-scheduler page so the files the container mounts never go stale.

Tips & Best Practices

  • •Use Docker secrets or mounted volumes for certificate storage
  • •Never embed certificates in Docker images
  • •Configure proper file permissions for certificate files in containers
  • •Monitor certificate expiry for containerized services

Technical Details

Container: Docker container SSL/TLS configuration
Storage: Secret management and volume mounting for certificates
Networking: Container network SSL configuration
Output: Docker SSL configuration recommendations

Related Tools

SSL Certificate Checker HSTS Preload Checker Security Header Analyzer DNS Propagation Checker Certificate Expiry Calendar Cloudflare SSL Checker Certificate Inventory