While our `shouldStartDomainRenewal` check is correct, `getCertPEM`
would always bail if the existing cert is not expired. Add the same
`shouldStartDomainRenewal` check to `getCertPEM` to make it proceed with
renewal when existing certs are still valid but should be renewed.
The extra check is expensive (ARI request towards LetsEncrypt), so cache
the last check result for 1hr to not degrade `tailscale serve`
performance.
Also, asynchronous renewal is great for `tailscale serve` but confusing
for `tailscale cert`. Add an explicit flag to `GetCertPEM` to force a
synchronous renewal for `tailscale cert`.
Fixes#8725
Signed-off-by: Andrew Lytvynov <awly@tailscale.com>
This updates all source files to use a new standard header for copyright
and license declaration. Notably, copyright no longer includes a date,
and we now use the standard SPDX-License-Identifier header.
This commit was done almost entirely mechanically with perl, and then
some minimal manual fixes.
Updates #6865
Signed-off-by: Will Norris <will@tailscale.com>