Go 1.27 enables GOEXPERIMENT=jsonv2 by default: encoding/json is now
backed by the json/v2 machinery, and github.com/go-json-experiment/json
compiles as a thin alias of the standard library's encoding/json/v2.
Several tag options and behaviors we relied on did not make the cut for
the final Go 1.27 API, breaking tailscaled at runtime and four packages'
tests. This change adapts to the final API while keeping the wire format
byte-for-byte identical on all Go versions.
First, the `format` tag option was demoted to experimental. Its mere
presence in a struct tag now makes marshaling and unmarshaling fail at
runtime. tailcfg.SSHAction.SessionDuration had `format:nano` (added in
a2dc517d7 to pin the v1 representation), so on Go 1.27 any netmap
containing an SSH policy failed to decode, breaking every PollNetMap.
Remove the option here and in net/speedtest; time.Duration still
marshals as int64 nanoseconds under encoding/json on all Go versions
(Go 1.27's v1 mode sets FormatDurationAsNano by default), so old
clients and servers are unaffected. Add a regression test locking in
the exact wire format.
Consequently, invert the cmd/vet jsontags rule: it previously required
an explicit `format` tag on time.Duration fields, which is now exactly
wrong. It now rejects any `format` tag option, which would have caught
this bug in CI.
Second, the `inline` tag option was renamed to `embed`. The standard
library silently ignores `inline`, while the pinned go-json-experiment
module (used on Go 1.26) only knows `inline`. Specify both options in
types/prefs and logtail; each implementation ignores the option it does
not know, producing identical output. Drop `inline` once we require
Go 1.27.
Third, encoding/json (v1) now dispatches to MarshalJSONTo and
UnmarshalJSONFrom methods and its v1 options flow into nested
jsonv2.MarshalEncode calls. Types whose v1 methods deliberately
routed through jsonv2 for v2 semantics (types/opt.Value, the
types/prefs preference types) would silently change wire format
(e.g. nil slices becoming null). Pin jsonv2.DefaultOptionsV2 in
their jsonv2 methods so the representation is the same regardless
of the entry point.
Finally, json.Marshal costs one more allocation under Go 1.27,
tripping the types/logger.AsJSON alloc test. Switch its fmt.Formatter
to jsonv2.MarshalWrite with explicit v1 options, which writes directly
to the fmt.State: one allocation on both toolchains with unchanged
output. Depaware files pick up the go-json-experiment/json/v1 options
shim as a new dependency of types/logger.
With this change, go test ./... passes with both Go 1.26.5 and
go1.27rc2.
Updates #20220
Fixes #20528
Fixes #20254
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
Change-Id: I694c7d57fd81e55a579c579e9be10032bca569d4
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.