SSL Cert - SMTP server failed to start

[williambonomo]

Hi Everyone,

We were using SMTP4dev on an Azure Container Instance with no issues. However, I was requested to enable the SMTP TLS using our SSL cert issued by GoDaddy. Knowing that Azure Container instance has some limitations with SSL cert I decided to create an image with our SSL.
When I run the container, I get the below error. I'm 100% sure the path to the key is correct.

2024-10-30 16:44:43 The SMTP server failed to start: System.IO.FileNotFoundException: Could not find file '/smtp4dev/mysslkey.key'.
2024-10-30 16:44:43 File name: '/smtp4dev/mysslkey.key'

This is how my Dockerfile looks like:

FROM rnwood/smtp4dev:latest

ENV ServerOptions__LockSettings=true
ENV ServerOptions__HostName=smtp4dev.ourdomain.io
ENV ServerOptions__Port=33
ENV ServerOptions__Urls=http://*:80
ENV ServerOptions__TlsMode=StartTls
ENV ServerOptions__TlsCertificate=myCrt.crt
ENV ServerOptions__TlsCertificatePrivateKey=mysslkey.key
ENV ServerOptions__TlsCertificatePassword=mypassword
ENV ServerOptions__SecureConnectionRequired=True
ENV ServerOptions__NumberOfMessagesToKeep=500

EXPOSE 80
EXPOSE 33
EXPOSE 143

I'm in no rush but if someone could help that would be great.

[Julien-Eyraud]

The docker file doesn't seem to copy the files.

[williambonomo]

The docker file doesn't seem to copy the files.

Hey Julien. Thank you for your reply.
Do you think it has something to do with the folder/file permission? I just tried running it from a different folder on my PC and got the same error.
Strangely, it doesn't complain about the .crt.

[rnwood]

The docker file doesn't seem to copy the files.

This is the answer. You can add the COPY command to your docker file to copy the required cert files into the container.

https://docs.docker.com/reference/dockerfile/#copy

However, it's recommended to map a volume into the container when it is created. This keeps the cert files out of your image.

https://docs.docker.com/engine/storage/bind-mounts/

[williambonomo]

The docker file doesn't seem to copy the files.

This is the answer. You can add the COPY command to your docker file to copy the required cert files into the container.

https://docs.docker.com/reference/dockerfile/#copy

However, it's recommended to map a volume into the container when it is created. This keeps the cert files out of your image.

https://docs.docker.com/engine/storage/bind-mounts/

Ohhh that's it, makes sense now. I should be more clear stating that I'm a Docker newbie, sorry.
Seem like it runs without errors now. Thank you!