#34302 add ipv6 square bracket support to launch_on_machine

[ssikdar1]

PR for #34302 to let launch_on_machine handle ipv6 address by adding support for the square bracket notation.

Note: this does not address the ipv6 socket related problems reported in the issue.

• add a function to handle both ipv4 and ipv6 host strings
• Add a few tests.
• Add a NEWS item.

Testing:
I added a unit test julia file. It includes managers.jl directly and tests some simple use cases.
127.0.0.1 , 127.0.0.1:80, [2001:db8::1], [2001:db8::1]:443

I also ran $ ./julia stdlib/Distributed/test/runtests.jl with no issues.

[Keno]

Please rebase this branch to only have the relevant commit.

[ssikdar1]

@Keno sorry about that! branch rebased

[StefanKarpinski]

Going a bit further, since you're introducing the parse_machine function, I would suggest that it should parse the port number all the way to validated port integer or nothing in the parse function rather than right afterwards. I was also going to suggest parsing the host part to an IPAddr (IPv4 or IPv6 instance) but it could also be a hostname, so there would be a lot of potential return types, which is not actually a big problem, but then it gets immediately turned back into a string and passing through the IPAddr type could lead to differences in formatting which might just confuse matters. So probably best to push the port validation into the parse_machine function but return the host as a string.

[ssikdar1]

So probably best to push the port validation into the parse_machine function but return the host as a string.

8b9bbb1 : Pushed the port validation to inside parse_machine , parse_machine still returns host as a string. Added some unit tests to test the port edge cases

[StefanKarpinski]

One simplifying comment but otherwise looks good!

[StefanKarpinski]

Ok. This is looking great. Now all you need is a NEWS entry! It should probably go in the standard library changes section under a "Distributed" subheading.

[StefanKarpinski]

This is good to go when CI passes. Whoever merges, please squash!

[Keno]

This test doesn't run unless it's added to runtests.jl

[StefanKarpinski]

Did you mean to close this? We're so close to being done here...

[ssikdar1]

sorry!! I had done a reset and force push without thinking, I must have closed the issue then by accident. I restored my fork to the previous commit and added a change for runtests, but seem unable to click the "reopen pull request" on github.

I opened a new PR here: #34494

[StefanKarpinski]

I can't reopen it either. Guess you'll need to make a new PR.