Comment by binsquare
8 hours ago
hey simon,
smol machines actually support exactly those things across macs,linux, windows btw: https://github.com/smol-machines/smolvm/blob/main/AGENTS.md#...
here's a snippet of how it looks like to configure that:
[network]
allow_hosts = ["api.github.com"] # hostname, also allows its subdomains
allow_host_patterns = ["example.com", "*.npmjs.org"] # exact names, or *. for subdomains only
allow_cidrs = ["10.0.0.0/8", "1.1.1.1"] # IP ranges or single IPs
[[network.credentials]]
name = "github"
environment_variable = "GITHUB_TOKEN"
+1 on smolvm! I provision a smolvm per job in preloop, a local/self-hosted github actions( https://github.com/preloopdev/preloop). iirc there was also some work to add a deny-cidr option as well which would give you more flexibility. But the egress filter captures most of what you need so it works great nonetheless.
love seeing preloop's work :)
how does it do it?
proxy in the middle (but cert pinning problems)
or DNS filtering? (but agent could have "memorized" stable IP)
Cert pinning: not a problem. we don't decrypt traffic, we just pass it through. The only exception is hosts you give a credential to, since we have to insert the key.
Memorized IP: doesn't work, the vm can only connect to an IP if it came from a DNS lookup of an allowed name. Any other IP is blocked.
A bit of "shared responsibility" philosophy kicking through but I try to have good defaults