open-nomad/helper/testlog/testlog.go
Drew Bailey 786989dbe3
New monitor pkg for shared monitor functionality
Adds new package that can be used by client and server RPC endpoints to
facilitate monitoring based off of a logger

clean up old code

small comment about write

rm old comment about minsize

rename to Monitor

Removes connection logic from monitor command

Keep connection logic in endpoints, use a channel to send results from
monitoring

use new multisink logger and interfaces

small test for dropped messages

update go-hclogger and update sink/intercept logger interfaces
2019-11-05 09:51:49 -05:00

109 lines
2.6 KiB
Go

// Package testlog creates a *log.Logger backed by *testing.T to ease logging
// in tests. This allows logs from components being tested to only be printed
// if the test fails (or the verbose flag is specified).
package testlog
import (
"bytes"
"io"
"log"
"os"
hclog "github.com/hashicorp/go-hclog"
)
// UseStdout returns true if NOMAD_TEST_STDOUT=1 and sends logs to stdout.
func UseStdout() bool {
return os.Getenv("NOMAD_TEST_STDOUT") == "1"
}
// LogPrinter is the methods of testing.T (or testing.B) needed by the test
// logger.
type LogPrinter interface {
Logf(format string, args ...interface{})
}
// writer implements io.Writer on top of a Logger.
type writer struct {
prefix string
t LogPrinter
}
// Write to an underlying Logger. Never returns an error.
func (w *writer) Write(p []byte) (n int, err error) {
w.t.Logf("%s%s", w.prefix, p)
return len(p), nil
}
// NewWriter creates a new io.Writer backed by a Logger.
func NewWriter(t LogPrinter) io.Writer {
if UseStdout() {
return os.Stdout
}
return &writer{t: t}
}
// NewPrefixWriter creates a new io.Writer backed by a Logger with a custom
// prefix per Write.
func NewPrefixWriter(t LogPrinter, prefix string) io.Writer {
if UseStdout() {
return &prefixStdout{[]byte(prefix)}
}
return &writer{prefix, t}
}
// New returns a new test logger. See https://golang.org/pkg/log/#New
func New(t LogPrinter, prefix string, flag int) *log.Logger {
if UseStdout() {
return log.New(os.Stdout, prefix, flag)
}
return log.New(&writer{t: t}, prefix, flag)
}
// WithPrefix returns a new test logger with the Lmicroseconds flag set.
func WithPrefix(t LogPrinter, prefix string) *log.Logger {
return New(t, prefix, log.Lmicroseconds)
}
// Logger returns a new test logger with the Lmicroseconds flag set and no
// prefix.
func Logger(t LogPrinter) *log.Logger {
return WithPrefix(t, "")
}
//HCLogger returns a new test hc-logger.
func HCLogger(t LogPrinter) hclog.InterceptLogger {
level := hclog.Trace
envLogLevel := os.Getenv("NOMAD_TEST_LOG_LEVEL")
if envLogLevel != "" {
level = hclog.LevelFromString(envLogLevel)
}
opts := &hclog.LoggerOptions{
Level: level,
Output: NewWriter(t),
IncludeLocation: true,
}
return hclog.NewInterceptLogger(opts)
}
type prefixStdout struct {
prefix []byte
}
// Write to stdout with a prefix per call containing non-whitespace characters.
func (w *prefixStdout) Write(p []byte) (int, error) {
if len(p) == 0 {
return 0, nil
}
// Skip prefix if only writing whitespace
if len(bytes.TrimSpace(p)) > 0 {
_, err := os.Stdout.Write(w.prefix)
if err != nil {
return 0, err
}
}
return os.Stdout.Write(p)
}