tailscale/logtail/config.go
Brad Fitzpatrick 5b06e32f33 logtail: add Config.Disabled to suppress the startup banner
NewLogger unconditionally writes a "logtail started" banner before
it returns, which callers that later call Logger.SetEnabled(false)
have no way to suppress: the banner is already buffered for upload
by the time the caller gets the logger back.

Add Config.Disabled so callers that know up front they want the
logger to start disabled (e.g. Android's remote-logging opt-out)
can seed the state before NewLogger's internal Write. The process-
wide Disable kill switch still takes precedence; SetEnabled can
still flip the state at runtime.

Updates #13174
Updates tailscale/tailscale-android#695

Change-Id: Icc4fa88c198447cf0faa707264dac84e359fe52c
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
2026-04-20 13:33:10 -07:00

76 lines
3.2 KiB
Go

// Copyright (c) Tailscale Inc & contributors
// SPDX-License-Identifier: BSD-3-Clause
package logtail
import (
"io"
"net/http"
"time"
"tailscale.com/tstime"
"tailscale.com/types/logid"
"tailscale.com/util/eventbus"
)
// DefaultHost is the default host name to upload logs to when
// Config.BaseURL isn't provided.
const DefaultHost = "log.tailscale.com"
const defaultFlushDelay = 2 * time.Second
const (
// CollectionNode is the name of a logtail Config.Collection
// for tailscaled (or equivalent: IPNExtension, Android app).
CollectionNode = "tailnode.log.tailscale.io"
)
type Config struct {
Collection string // collection name, a domain name
PrivateID logid.PrivateID // private ID for the primary log stream
CopyPrivateID logid.PrivateID // private ID for a log stream that is a superset of this log stream
BaseURL string // if empty defaults to "https://log.tailscale.com"
HTTPC *http.Client // if empty defaults to http.DefaultClient
SkipClientTime bool // if true, client_time is not written to logs
LowMemory bool // if true, logtail minimizes memory use
Clock tstime.Clock // if set, Clock.Now substitutes uses of time.Now
Stderr io.Writer // if set, logs are sent here instead of os.Stderr
Bus *eventbus.Bus // if set, uses the eventbus for awaitInternetUp instead of callback
StderrLevel int // max verbosity level to write to stderr; 0 means the non-verbose messages only
Buffer Buffer // temp storage, if nil a MemoryBuffer
CompressLogs bool // whether to compress the log uploads
MaxUploadSize int // maximum upload size; 0 means using the default
// MetricsDelta, if non-nil, is a func that returns an encoding
// delta in clientmetrics to upload alongside existing logs.
// It can return either an empty string (for nothing) or a string
// that's safe to embed in a JSON string literal without further escaping.
MetricsDelta func() string
// FlushDelayFn, if non-nil is a func that returns how long to wait to
// accumulate logs before uploading them. 0 or negative means to upload
// immediately.
//
// If nil, a default value is used. (currently 2 seconds)
FlushDelayFn func() time.Duration
// IncludeProcID, if true, results in an ephemeral process identifier being
// included in logs. The ID is random and not guaranteed to be globally
// unique, but it can be used to distinguish between different instances
// running with same PrivateID.
IncludeProcID bool
// IncludeProcSequence, if true, results in an ephemeral sequence number
// being included in the logs. The sequence number is incremented for each
// log message sent, but is not persisted across process restarts.
IncludeProcSequence bool
// Disabled, if true, causes the returned [Logger] to start in the
// disabled state, dropping entries without buffering or uploading
// (equivalent to calling [Logger.SetEnabled] with false immediately).
// It applies before the internal startup banner is written, so no
// log entries are emitted until [Logger.SetEnabled] is called with
// true. The process-wide [Disable] kill switch still takes precedence.
Disabled bool
}