Using your own SSL certificate with Portainer
By default, Portainer’s web interface and API is exposed over HTTPS with a self-signed certificate generated by the installation. This can be replaced with your own SSL certificate either after installation via the Portainer UI or during installation, as explained in this article.
When using your own externally-issued certificate, ensure that you include the full certificate chain (including any intermediate certificates) in the file you provide via --sslcert. Without this you may face certificate validation issues. Your certificate chain can be obtained either from your certificate issuer or the What's My Chain Cert? website.

Using your own SSL certificate on Docker Standalone

Portainer expects certificates in PEM format.
Use the --sslcert and --sslkey flags during installation.
Upload your certificate (including the chain) and key to the server running Portainer, then start Portainer referencing them. The following command assumes your certificates are stored in /path/to/your/certs with the filenames portainer.crt and portainer.key, and bind-mounts the directory to /certs in the Portainer container:
docker run -d -p 9443:9443 -p 8000:8000 \
--name portainer --restart always \
-v /var/run/docker.sock:/var/run/docker.sock \
-v portainer_data:/data \
-v /path/to/your/certs:/certs \
portainer/portainer-ee:latest --sslcert /certs/portainer.crt --sslkey /certs/portainer.key
Alternatively, Certbot can be used to generate a certificate and a key. Because Docker has issues with symlinks, if you use Certbot you will need to pass both the 'live' and 'archive' directories as volumes. For example:
docker run -d -p 9443:9443 -p 8000:8000 \
--name portainer --restart always \
-v /var/run/docker.sock:/var/run/docker.sock \
-v portainer-data:/data \
-v /etc/letsencrypt/live/yourdomain:/certs/live/yourdomain:ro \
-v /etc/letsencrypt/archive/yourdomain:/certs/archive/yourdomain:ro \
portainer/portainer-ee:latest --sslcert /certs/live/yourdomain/cert.pem --sslkey /certs/live/yourdomain/privkey.pem
When you're finished, you can navigate to https://$ip-docker-host:9443.

Using your own SSL certificate on Docker Swarm

To provide your own SSL certificate for Docker Swarm, simply define the portainer.sslcert and portainer.sslkey secrets, and the installation manifest will automatically detect and use them:
docker secret create portainer.sslcert /path/to/your/certificate.crt
docker secret create portainer.sslkey /path/to/your/certificate.key
Next, retrieve the stack YML manifest:
Linux and Windows with Docker Desktop
Windows Container Services
curl -L -o portainer-agent-stack.yml
curl -o portainer-agent-stack.yml
Finally, use the downloaded YML manifest to deploy your stack:
docker stack deploy -c portainer-agent-stack.yml portainer
For more information about secrets, read Docker's own documentation.

Using your own SSL certificate on Kubernetes (via Helm)

If it doesn't already exist, create the portainer namespace:
kubectl create namespace portainer
Next, create a TLS secret containing the full certificate chain and matching private key:
kubectl create secret tls portainer-tls-secret -n portainer \
--cert=/path/to/cert/file \
Install via helm with the tls.existingSecret parameter set to the name of the secret you just created:
Load Balancer
helm install -n portainer portainer portainer/portainer \
--set tls.existingSecret=portainer-tls-secret \
--set enterpriseEdition.enabled=true
helm install -n portainer portainer portainer/portainer \
--set tls.existingSecret=portainer-tls-secret \
--set service.type=LoadBalancer \
--set enterpriseEdition.enabled=true