Support wildcards in options.hosts

[tom-miseur]

Feature Description

It would be useful if it were possible to use wildcards in options.hosts in the same way we can with blockHostnames.

So instead of:

export const options = {
  hosts: {
    'subdomain1.k6.io': '1.2.3.4',
    'subdomain2.k6.io': '1.2.3.4',
  },
}

One could specify any subdomain:

export const options = {
  hosts: {
    '*.k6.io': '1.2.3.4',
  },
}

Suggested Solution (optional)

No response

Already existing or connected issues / PRs (optional)

No response

[eugercek]

May I pick this up?

[na--]

@eugercek, sure, though please make sure to add plenty of tests and ideally also some benchmarks.

[eugercek]

I have some questions to proceed:

1. I found the Trie implementation from Add blocking by hostname patterns (--block-hostname) #1532 and used the same approach to handle wildcards. But there's one difference options.hosts need to store a (IP or P:Port), so I created a new type. Since we use, don't use 1.18 can't use generics to create a generic type. Is it ok to introduce a new type? The new type: https://github.com/eugercek/k6/blob/wildcard-host/lib/types/addresstrie.go#L35

• There are two types:
  • matchTrieNode is a trie node with leaf indication as a value( not empty string).
  • AddressTrie wrapper around matchTrieNode.

2. Currently, hosts doesn't do hostname validation should I add it?

3. What are your opinions on moving to iterative trie implementation rather than the current recursive approach?

4. Because of circular dependency, I can't import go.k6.io/k6/lib from the types package. Ideally, using types.NewAddressTrie() with a lib.Hostaddress argument would be better, but not sure how to proceed.

• Currently, I get it as a string and will handle it in Dialer
• Maybe can use net.TCPAddr

[na--]

Closed by #2747

[tom-miseur]

Thank you very much for your contribution, @eugercek!