You can create X.509 Credential Sets in an intersystems IRIS namespace, then access the credential set in a production.

Several pre-built adaptors like the HTTP Inbound Adapter use this approach.

Here is documentation on creating InterSystems IRIS Credential Sets

I installed telnet in an IRIS container using:

docker exec -u root -it <container-name> apt-get install telnet

Then tested it using:

docker exec -u root -it <container-name> telnet <target-ip> <target-port>

This requires your container to be networked with the target. So a full example:

    docker network create networkECP
    docker network connect networkECP iris-data-server
    docker network connect networkECP iris-app-1
    docker network inspect networkECP
    docker exec -u root -it iris-app-1 ping iris-data-server
    docker exec -u root -it iris-app-1 apt-get update && apt-get install telnet
    docker exec -u root -it iris-app-1 telnet iris-data-server 1972