Use unused port for registry #21
Conversation
- avoid dependency on unsupported openssl 1.0.2 - extraction of port numbers is simpler
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Hi, thanks for the PR! Scanning ports to find one open usually has two big drawbacks: it is not atomic (the port may get assigned by the time the registry starts) and it's somewhat slow. I would rather use port |
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Thanks for the quick reply. You are right, the operation is not atomic. Concerning speed, it is not a port scanning if I understand that correctly and it is rather fast. I shortly thought about port I don't need it asap. I was investigating with nix&npm and your package works nicely. I was looking into separating the creation of |
- for some reasons, using port 0 does select a random port, but npm fails when retrieving data from it (does it crash?)
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@nmattia I made an update that now binds to a random port. Unfortunately, using port Another challenge was to get the port that has been allocated. I first thought to retrieve it somehow from stdout. But that seems not that trivial since the application continues to run. As we anyway have to wait for the registry to start, I don't think retrieving the information with Let me know what you think about the new solution. |
This is an alternative solution to pull request nix-community#21, which implements picking a random TCP port for the registry. While I haven't found the exact reason why it has to be randomized, I can only guess that it's to prevent port conflicts in unsandboxed builds. The implementation also has few ugly workarounds (eg. using lsof to get the port number), but the main issue I see is that even if the port is random, any user/process on the system can still connect to that port. So instead of picking a random TCP port, let's simply not use IP sockets at all and use ip2unix to force NPM into connecting to the Unix socket. We're now using a dummy IP address (127.0.0.100) for the registry URL in order to be able to match the registry URL in the ip2unix rule as a distinct host and at the same time prevent silent failure in case we forgot to transform/wrap sockets at some point. Signed-off-by: aszlig <aszlig@nix.build> Fixes: nix-community#4, nix-community#10
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Closing in favor of #24, thanks for the inspiration! |
This PR introduces a script to select an unused port for the registry. This should essentially address #10.
The solution has a dependency on
lsof, but sincencis used already, I think that should be okay.Moreover, the registry is terminated via a
trap ... EXIT, so it is shutdown even in case of unexpected errors.