terraform/internal/logging/logging.go

121 lines
2.9 KiB
Go

package logging
import (
"fmt"
"io"
"io/ioutil"
"log"
"os"
"strings"
"syscall"
"github.com/hashicorp/go-hclog"
)
// These are the environmental variables that determine if we log, and if
// we log whether or not the log should go to a file.
const (
EnvLog = "TF_LOG" // Set to True
EnvLogFile = "TF_LOG_PATH" // Set to a file
)
// ValidLevels are the log level names that Terraform recognizes.
var ValidLevels = []LogLevel{"TRACE", "DEBUG", "INFO", "WARN", "ERROR"}
// logger is the global hclog logger
var logger hclog.Logger
func init() {
logger = NewHCLogger("")
}
// LogOutput determines where we should send logs (if anywhere) and the log level.
func LogOutput() (logOutput io.Writer, err error) {
return logger.StandardWriter(&hclog.StandardLoggerOptions{InferLevels: true}), nil
}
// HCLogger returns the default global loggers
func HCLogger() hclog.Logger {
return logger
}
// NewHCLogger returns a new hclog.Logger instance with the given name
func NewHCLogger(name string) hclog.Logger {
logOutput := io.Writer(os.Stderr)
logLevel := CurrentLogLevel()
if logLevel == "" {
logOutput = ioutil.Discard
}
if logPath := os.Getenv(EnvLogFile); logPath != "" {
f, err := os.OpenFile(logPath, syscall.O_CREAT|syscall.O_RDWR|syscall.O_APPEND, 0666)
if err != nil {
fmt.Fprintf(os.Stderr, "Error opening log file: %v\n", err)
} else {
logOutput = f
}
}
return hclog.New(&hclog.LoggerOptions{
Name: name,
Level: hclog.LevelFromString(logLevel),
Output: logOutput,
})
}
// SetOutput checks for a log destination with LogOutput, and calls
// log.SetOutput with the result. If LogOutput returns nil, SetOutput uses
// ioutil.Discard. Any error from LogOutout is fatal.
func SetOutput() {
out, err := LogOutput()
if err != nil {
log.Fatal(err)
}
if out == nil {
out = ioutil.Discard
}
// the hclog logger will add the prefix info
log.SetFlags(0)
log.SetPrefix("")
log.SetOutput(out)
}
// CurrentLogLevel returns the current log level string based the environment vars
func CurrentLogLevel() string {
envLevel := strings.ToUpper(os.Getenv(EnvLog))
if envLevel == "" {
return ""
}
logLevel := "TRACE"
if isValidLogLevel(envLevel) {
logLevel = envLevel
} else {
log.Printf("[WARN] Invalid log level: %q. Defaulting to level: TRACE. Valid levels are: %+v",
envLevel, ValidLevels)
}
if logLevel != "TRACE" {
log.Printf("[WARN] Log levels other than TRACE are currently unreliable, and are supported only for backward compatibility.\n Use TF_LOG=TRACE to see Terraform's internal logs.\n ----")
}
return logLevel
}
// IsDebugOrHigher returns whether or not the current log level is debug or trace
func IsDebugOrHigher() bool {
level := string(CurrentLogLevel())
return level == "DEBUG" || level == "TRACE"
}
func isValidLogLevel(level string) bool {
for _, l := range ValidLevels {
if level == string(l) {
return true
}
}
return false
}