Updates tailscale/tailscale#4136
This PR is the first round of work to move from encoding health warnings as strings and use structured data instead. The current health package revolves around the idea of Subsystems. Each subsystem can have (or not have) a Go error associated with it. The overall health of the backend is given by the concatenation of all these errors.
This PR polishes the concept of Warnable introduced by @bradfitz a few weeks ago. Each Warnable is a component of the backend (for instance, things like 'dns' or 'magicsock' are Warnables). Each Warnable has a unique identifying code. A Warnable is an entity we can warn the user about, by setting (or unsetting) a WarningState for it. Warnables have:
- an identifying Code, so that the GUI can track them as their WarningStates come and go
- a Title, which the GUIs can use to tell the user what component of the backend is broken
- a Text, which is a function that is called with a set of Args to generate a more detailed error message to explain the unhappy state
Additionally, this PR also begins to send Warnables and their WarningStates through LocalAPI to the clients, using ipn.Notify messages. An ipn.Notify is only issued when a warning is added or removed from the Tracker.
In a next PR, we'll get rid of subsystems entirely, and we'll start using structured warnings for all errors affecting the backend functionality.
Signed-off-by: Andrea Gottardo <andrea@gottardo.me>
Previously it was both metadata about the class of warnable item as
well as the value.
Now it's only metadata and the value is per-Tracker.
Updates #11874
Updates #4136
Change-Id: Ia1ed1b6c95d34bc5aae36cffdb04279e6ba77015
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This moves most of the health package global variables to a new
`health.Tracker` type.
But then rather than plumbing the Tracker in tsd.System everywhere,
this only goes halfway and makes one new global Tracker
(`health.Global`) that all the existing callers now use.
A future change will eliminate that global.
Updates #11874
Updates #4136
Change-Id: I6ee27e0b2e35f68cb38fecdb3b2dc4c3f2e09d68
Signed-off-by: Brad Fitzpatrick <bradfitz@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>
Run an inotify goroutine and watch if another program takes over
/etc/inotify.conf. Log if so.
For now this only logs. In the future I want to wire it up into the
health system to warn (visible in "tailscale status", etc) about the
situation, with a short URL to more info about how you should really
be using systemd-resolved if you want programs to not fight over your
DNS files on Linux.
Updates #4254 etc etc
Change-Id: I86ad9125717d266d0e3822d4d847d88da6a0daaa
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>