Check for already running corectl & stop old version before upgrade

[quinncomendant]

I've just brew upgrade corectl and run the new version:

corectld start;
corectl run --offline --channel beta --volume ~/var/coreos/var_lib_docker3.img --cloud_config ~/var/coreos/docker-only-with-persistent-storage.txt --cpus 1 --memory 1024 --name containerland --uuid 11111111-1111-1111-1111-111111111111 --debug;

Running corectl failed with:

[ERROR] Couldn't decode response. Unable to grab VM's IP after 30s (!)... Aborted

I then noticed my old version of corectl was still running:

[q@x] ps ax -o pid,user,command | grep corectl
68775 root  corectl xhyve bGlieGh5dmVfYnVnIC1zIDA6MCxob3N0YnJpZGdlIC1zIDUsdmlydGlvLXJuZCAtbCBjb20xLHN0ZGlvIC1zIDMxLGxwYyAtVSAxMTExMTExMS0xMTExLTExMTEtMTExMS0xMTExMTExMTExMTEgLW0gMTAyNE0gLWMgMSAtQSAtcyAyOjAsdmlydGlvLW5ldCAtcyA0OjAsdmlydGlvLWJsaywvVXNlcnMvcS92YXIvY29yZW9zL3Zhcl9saWJfZG9ja2VyMy5pbWc= a2V4ZWMsL1VzZXJzL3EvLmNvcmVvcy9pbWFnZXMvYmV0YS8xMDY4LjIuMC9jb3Jlb3NfcHJvZHVjdGlvbl9weGUudm1saW51eiwvVXNlcnMvcS8uY29yZW9zL2ltYWdlcy9iZXRhLzEwNjguMi4wL2NvcmVvc19wcm9kdWN0aW9uX3B4ZV9pbWFnZS5jcGlvLmd6LA== ZWFybHlwcmludGs9c2VyaWFsIGNvbnNvbGU9dHR5UzAgY29yZW9zLmF1dG9sb2dpbiB1dWlkPTExMTExMTExLTExMTEtMTExMS0xMTExLTExMTExMTExMTExMSBlbmRwb2ludD1odHRwOi8vMTkyLjE2OC42NC4xOjQ5ODI2L2NvbnRhaW5lcmxhbmQgY2xvdWQtY29uZmlnLXVybD1odHRwOi8vMTkyLjE2OC42NC4xOjQ5ODI2L2NvbnRhaW5lcmxhbmQvY2xvdWQtY29uZmln
20346 root  /usr/local/bin/corectld start --user q

Of course this causes problems (the above error probably just one). Since some users might not notice that an old version is running in the background, I suggest two changes:

• corectl and corectld check if old (or same) version already running and gives error if so.
• update Homebrew recipe so it will stop the old running copy of corectl during upgrade.

[AntonioMeireles]

@quinncomendant the 1st part of your suggestion is doable and very relevant, albeit tricky - as whre we have most interest in stopping running corectl sessions is when they are pre 0.7.x and in pre-0.7.x there's no corectld to do that for us cleanly.
The homebrew part is trickier as afaict there 's no way to do that from a brew Formula. (and there's the additional issue that corectld is running as root). Anyway looking at ways to smooth this. Thanks!