There seem to be a lot of good alternatives here, but all seem to rely on running curl and potentially host directly from a shell. Please be aware that if you're intending to call all of the application instances (e.g. web application) from within one of the application instances (not just in the pod, but from within the application code itself), spawning a shell to execute script commands is absolutely not a good practice - any time you spawn a command shell from inside your app, you leave an exploitable attack surface that can allow a clever hacker to potentially escalate privileges or at least run malicious code (https://attack.mitre.org/techniques/T1059/003/ speaks about Windows, but the same theory applies to Linux). Do yourself a favor and make a call to an OS function to connect to an external resource instead of spawning a shell to use curl.