log: improve rounding logic for log rolling directives (#3367)

* For `roll_size` and `roll_keep_for` directives, round up instead of down.
  For example, if a user wants to be able to look back on 36 hours of logs,
  but you must round to a 24-hour multiple, then it's better to round up to
  48 hours (which includes the desired 36 hours) instead of down to 24 hours.

* `roll_size` had an off-by-one error that caused the size to be as much as
  1 MB larger than requested. For example, requests of `1MB` and `1.1MB`
  both became 2 MB. Now `1MB` means 1 MB, and `1.1MB` is rounded up to 2 MB.
This commit is contained in:
Jeremy Lin 2020-05-07 12:06:00 -07:00 committed by GitHub
parent c8da8ca673
commit bf8c3c25c1
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@ -17,6 +17,7 @@ package logging
import (
"fmt"
"io"
"math"
"os"
"path/filepath"
"strconv"
@ -138,8 +139,15 @@ func (fw FileWriter) OpenWriter() (io.WriteCloser, error) {
// roll_keep_for <days>
// }
//
// The roll_size value will be rounded down to number of megabytes (MiB).
// The roll_keep_for duration will be rounded down to number of days.
// The roll_size value has megabyte resolution.
// Fractional values are rounded up to the next whole megabyte (MiB).
//
// The roll_keep_for duration has day resolution.
// Fractional values are rounded up to the next whole number of days.
//
// If any of the roll_size, roll_keep, or roll_keep_for subdirectives are
// omitted or set to a zero value, then Caddy's default value for that
// subdirective is used.
func (fw *FileWriter) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
for d.Next() {
if !d.NextArg() {
@ -168,7 +176,7 @@ func (fw *FileWriter) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
if err != nil {
return d.Errf("parsing size: %v", err)
}
fw.RollSizeMB = int(size)/1024/1024 + 1
fw.RollSizeMB = int(math.Ceil(float64(size) / humanize.MiByte))
case "roll_keep":
var keepStr string
@ -190,7 +198,10 @@ func (fw *FileWriter) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
if err != nil {
return d.Errf("parsing roll_keep_for duration: %v", err)
}
fw.RollKeepDays = int(keepFor.Hours()) / 24
if keepFor < 0 {
return d.Errf("negative roll_keep_for duration: %v", keepFor)
}
fw.RollKeepDays = int(math.Ceil(keepFor.Hours() / 24))
}
}
}