envknob: support changing envknobs post-init

Updates #5114

Change-Id: Ia423fc7486e1b3f3180a26308278be0086fae49b
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick
2022-09-14 12:49:39 -07:00
committed by Brad Fitzpatrick
parent 33ee2c058e
commit 74674b110d
31 changed files with 311 additions and 167 deletions

View File

@@ -68,7 +68,6 @@ import (
)
var controlDebugFlags = getControlDebugFlags()
var canSSH = envknob.CanSSHD()
func getControlDebugFlags() []string {
if e := envknob.String("TS_DEBUG_CONTROL_FLAGS"); e != "" {
@@ -1510,12 +1509,12 @@ func (b *LocalBackend) tellClientToBrowseToURL(url string) {
}
// For testing lazy machine key generation.
var panicOnMachineKeyGeneration = envknob.Bool("TS_DEBUG_PANIC_MACHINE_KEY")
var panicOnMachineKeyGeneration = envknob.RegisterBool("TS_DEBUG_PANIC_MACHINE_KEY")
func (b *LocalBackend) createGetMachinePrivateKeyFunc() func() (key.MachinePrivate, error) {
var cache syncs.AtomicValue[key.MachinePrivate]
return func() (key.MachinePrivate, error) {
if panicOnMachineKeyGeneration {
if panicOnMachineKeyGeneration() {
panic("machine key generated")
}
if v, ok := cache.LoadOk(); ok {
@@ -1752,7 +1751,7 @@ func (b *LocalBackend) loadStateLocked(key ipn.StateKey, prefs *ipn.Prefs) (err
// setAtomicValuesFromPrefs populates sshAtomicBool and containsViaIPFuncAtomic
// from the prefs p, which may be nil.
func (b *LocalBackend) setAtomicValuesFromPrefs(p *ipn.Prefs) {
b.sshAtomicBool.Store(p != nil && p.RunSSH && canSSH)
b.sshAtomicBool.Store(p != nil && p.RunSSH && envknob.CanSSHD())
if p == nil {
b.containsViaIPFuncAtomic.Store(tsaddr.NewContainsIPFunc(nil))
@@ -1967,7 +1966,7 @@ func (b *LocalBackend) checkSSHPrefsLocked(p *ipn.Prefs) error {
default:
return errors.New("The Tailscale SSH server is not supported on " + runtime.GOOS)
}
if !canSSH {
if !envknob.CanSSHD() {
return errors.New("The Tailscale SSH server has been administratively disabled.")
}
if envknob.SSHIgnoreTailnetPolicy() || envknob.SSHPolicyFile() != "" {
@@ -2032,7 +2031,7 @@ func (b *LocalBackend) EditPrefs(mp *ipn.MaskedPrefs) (*ipn.Prefs, error) {
b.logf("EditPrefs check error: %v", err)
return nil, err
}
if p1.RunSSH && !canSSH {
if p1.RunSSH && !envknob.CanSSHD() {
b.mu.Unlock()
b.logf("EditPrefs requests SSH, but disabled by envknob; returning error")
return nil, errors.New("Tailscale SSH server administratively disabled.")
@@ -2854,7 +2853,7 @@ func (b *LocalBackend) applyPrefsToHostinfo(hi *tailcfg.Hostinfo, prefs *ipn.Pre
hi.ShieldsUp = prefs.ShieldsUp
var sshHostKeys []string
if prefs.RunSSH && canSSH {
if prefs.RunSSH && envknob.CanSSHD() {
// TODO(bradfitz): this is called with b.mu held. Not ideal.
// If the filesystem gets wedged or something we could block for
// a long time. But probably fine.
@@ -3073,7 +3072,7 @@ func (b *LocalBackend) ResetForClientDisconnect() {
b.setAtomicValuesFromPrefs(nil)
}
func (b *LocalBackend) ShouldRunSSH() bool { return b.sshAtomicBool.Load() && canSSH }
func (b *LocalBackend) ShouldRunSSH() bool { return b.sshAtomicBool.Load() && envknob.CanSSHD() }
// ShouldHandleViaIP reports whether whether ip is an IPv6 address in the
// Tailscale ULA's v6 "via" range embedding an IPv4 address to be forwarded to

View File

@@ -478,8 +478,8 @@ func (panicOnUseTransport) RoundTrip(*http.Request) (*http.Response, error) {
// Issue 1573: don't generate a machine key if we don't want to be running.
func TestLazyMachineKeyGeneration(t *testing.T) {
defer func(old bool) { panicOnMachineKeyGeneration = old }(panicOnMachineKeyGeneration)
panicOnMachineKeyGeneration = true
defer func(old func() bool) { panicOnMachineKeyGeneration = old }(panicOnMachineKeyGeneration)
panicOnMachineKeyGeneration = func() bool { return true }
var logf logger.Logf = logger.Discard
store := new(mem.Store)

View File

@@ -24,7 +24,7 @@ import (
"tailscale.com/types/tkatype"
)
var networkLockAvailable = envknob.Bool("TS_EXPERIMENTAL_NETWORK_LOCK")
var networkLockAvailable = envknob.RegisterBool("TS_EXPERIMENTAL_NETWORK_LOCK")
type tkaState struct {
authority *tka.Authority
@@ -82,7 +82,7 @@ func (b *LocalBackend) NetworkLockInit(keys []tka.Key) error {
if b.tka != nil {
return errors.New("network-lock is already initialized")
}
if !networkLockAvailable {
if !networkLockAvailable() {
return errors.New("this is an experimental feature in your version of tailscale - Please upgrade to the latest to use this.")
}
if !b.CanSupportNetworkLock() {

View File

@@ -73,7 +73,7 @@ func (h *Handler) certDir() (string, error) {
return full, nil
}
var acmeDebug = envknob.Bool("TS_DEBUG_ACME")
var acmeDebug = envknob.RegisterBool("TS_DEBUG_ACME")
func (h *Handler) serveCert(w http.ResponseWriter, r *http.Request) {
if !h.PermitWrite && !h.PermitCert {
@@ -96,7 +96,7 @@ func (h *Handler) serveCert(w http.ResponseWriter, r *http.Request) {
now := time.Now()
logf := logger.WithPrefix(h.logf, fmt.Sprintf("cert(%q): ", domain))
traceACME := func(v any) {
if !acmeDebug {
if !acmeDebug() {
return
}
j, _ := json.MarshalIndent(v, "", "\t")