Include TLS information into INFO command output

[moredure]

Describe the solution you'd like
Include server TLS certificate information such as common name, expiration date, issue date into server section of INFO output

[kostasrim]

@moredure is this on Redis/Valkey as well ?

[romange]

I do not think so that Valkey displays this. @moredure can you provide more details on how you want to use this feature?
is it for automated systems or for manual inspection?

[moredure]

I do not think so that Valkey displays this. @moredure can you provide more details on how you want to use this feature? is it for automated systems or for manual inspection?

Yeap, just for manual inspection, to check that TLS is up to date or have expected common name, etc without using openssl or any advanced tools

[moredure]

@moredure is this on Redis/Valkey as well ?

I've not seen it there

[Lakshyadevelops]

@romange @kostasrim
I would like to take this on, I have understood the ServerFamily::Info(). Any leads as to where i can start to get this data ?

[romange]

@moredure what does it mean to have a proper common name?

[moredure]

@moredure what does it mean to have a proper common name?

I've meant to be able to see certificate CN/SAN, etc

[romange]

@Lakshyadevelops the SSL context is initialized inside CreateSslServerCntx (dragonfly_listener.cc) but I do not know how to fetch the certificate details from it - some learnings are required to complete the task.

[Lakshyadevelops]

So I looked into it. Using openssl I can easily get all the info.

My plan is to get the certificate location using GetFlag(FLAGS_tls_cert_file) and then read the certificate to get all the necessary info. All this code will be in server_family::Info().
Another approach could be we store this information at startup but if sometime after the certificate is refreshed then we will be displaying outdated info. I would prefer the former.

I tried first to generate a tls key and certificate for the server but I got E20240930 16:04:48.690333 1654 dragonfly_listener.cc:89] Failed to load TLS key

Is there any guide to generating tls keys correctly? I could only find this https://www.dragonflydb.io/docs/managing-dragonfly/using-tls
@romange

[moredure]

@Lakshyadevelops I don't like first approach because of we might fetch not currently used certificates (no tls reload issued yet, but files/symlink was updated)
any chance to extract from some runtime data instead of loading current files, or it's incapsulated within lib and we have no access to this data directly?
Probably it make sense to record certificate used during startup and in case of tls reload.

To generate cert/key you can search for openssl entry within tests directory, there was some python helpers to generate.

[romange]

I would also like to understand what does not work in https://www.dragonflydb.io/docs/managing-dragonfly/using-tls

and fix it. Can you please provide exact sequence of how you create certificates and how you run dragonfly (what arguments)?

[romange]

actually this doc is not very good for local development. so yeah, better use locally generated certificates.
This worked for me:

openssl req -x509 -newkey rsa:4096 -days 10 -nodes -keyout ca-key.pem -out ca-cert.pem --subj "/C=GR/ST=SKG/L=Thessaloniki/O=KK/OU=AcmeStudios/CN=Gr"

openssl req -newkey rsa:4096 -nodes -keyout df-key.pem -out df-req.pem --subj \
"/C=GR/ST=SKG/L=Thessaloniki/O=KK/OU=Comp/CN=Gr"

openssl x509 -req -in df-req.pem -days 10 -CA ca-cert.pem -CAkey ca-key.pem -CAcreateserial -out df-cert.pem

./dragonfly --tls --tls_key_file=./df-key.pem --tls_cert_file=./df-cert.pem --requirepass=foo

redis-cli --tls  --insecure -a foo PING

[Lakshyadevelops]

Thanks for this insight @moredure. Agreed we should choose the second approach btw it was an example of what not to do and we are choosing it 😂.

btw how do we issue TLS reload ? I could not find any relevant command in dragonflydb docs.
Redis TLS reload
We do support single value config update but not multiple simultaneously.

Also I am not familiar with how clusters in K8 manage certificates. Ik they are using dragonfly-operator but how it exactly updates certificates is still unclear. And would this approach work here I am not sure.