Use linkat via /proc/self/fd with AT_SYMLINK_FOLLOW to create a
hardlink of the test binary instead of copying it. This avoids
copying ~50MB+ binaries into each test's temp directory, making
test setup faster and reducing disk I/O.
The simpler os.Link(b.Path, ret.Path) can't be used here because
the source binary lives in the first test's TempDir, which may be
cleaned up before later tests call CopyTo. The open FD keeps the
inode alive after the path is deleted, but os.Link needs a valid
path. (See also b9f468240f which tried os.Link but is racy for
this reason.)
The /proc/self/fd approach works without elevated privileges,
unlike AT_EMPTY_PATH which requires CAP_DAC_READ_SEARCH. If the
linkat fails for any reason (e.g. cross-filesystem temp dirs), it
falls back to the existing full-copy path.
Fixes #19397
Change-Id: I4b1f97f7e63a9ae9e09dce36dfbdd1f6cff92320
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Tailscale
Private WireGuard® networks made easy
Overview
This repository contains the majority of Tailscale's open source code.
Notably, it includes the tailscaled daemon and
the tailscale CLI tool. The tailscaled daemon runs on Linux, Windows,
macOS, and to varying degrees
on FreeBSD and OpenBSD. The Tailscale iOS and Android apps use this repo's
code, but this repo doesn't contain the mobile GUI code.
Other Tailscale repos of note:
- the Android app is at https://github.com/tailscale/tailscale-android
- the Synology package is at https://github.com/tailscale/tailscale-synology
- the QNAP package is at https://github.com/tailscale/tailscale-qpkg
- the Chocolatey packaging is at https://github.com/tailscale/tailscale-chocolatey
For background on which parts of Tailscale are open source and why, see https://tailscale.com/opensource/.
Using
We serve packages for a variety of distros and platforms at https://pkgs.tailscale.com.
Other clients
The macOS, iOS, and Windows clients use the code in this repository but additionally include small GUI wrappers. The GUI wrappers on non-open source platforms are themselves not open source.
Building
We always require the latest Go release, currently Go 1.26. (While we build releases with our Go fork, its use is not required.)
go install tailscale.com/cmd/tailscale{,d}
If you're packaging Tailscale for distribution, use build_dist.sh
instead, to burn commit IDs and version info into the binaries:
./build_dist.sh tailscale.com/cmd/tailscale
./build_dist.sh tailscale.com/cmd/tailscaled
If your distro has conventions that preclude the use of
build_dist.sh, please do the equivalent of what it does in your
distro's way, so that bug reports contain useful version information.
Bugs
Please file any issues about this code or the hosted service on the issue tracker.
Contributing
PRs welcome! But please file bugs. Commit messages should reference bugs.
We require Developer Certificate of
Origin
Signed-off-by lines in commits.
See commit-messages.md (or skim git log) for our commit message style.
About Us
Tailscale is primarily developed by the people at https://github.com/orgs/tailscale/people. For other contributors, see:
- https://github.com/tailscale/tailscale/graphs/contributors
- https://github.com/tailscale/tailscale-android/graphs/contributors
Legal
WireGuard is a registered trademark of Jason A. Donenfeld.