coredns/plugin/cache/setup.go
Chris O'Haver 6c8581445e
fix keepttl parsing (#6250)
Signed-off-by: Chris O'Haver <cohaver@infoblox.com>
2023-08-09 08:32:50 -04:00

261 lines
6.3 KiB
Go

package cache
import (
"errors"
"fmt"
"strconv"
"strings"
"time"
"github.com/coredns/caddy"
"github.com/coredns/coredns/core/dnsserver"
"github.com/coredns/coredns/plugin"
"github.com/coredns/coredns/plugin/pkg/cache"
clog "github.com/coredns/coredns/plugin/pkg/log"
)
var log = clog.NewWithPlugin("cache")
func init() { plugin.Register("cache", setup) }
func setup(c *caddy.Controller) error {
ca, err := cacheParse(c)
if err != nil {
return plugin.Error("cache", err)
}
c.OnStartup(func() error {
ca.viewMetricLabel = dnsserver.GetConfig(c).ViewName
return nil
})
dnsserver.GetConfig(c).AddPlugin(func(next plugin.Handler) plugin.Handler {
ca.Next = next
return ca
})
return nil
}
func cacheParse(c *caddy.Controller) (*Cache, error) {
ca := New()
j := 0
for c.Next() {
if j > 0 {
return nil, plugin.ErrOnce
}
j++
// cache [ttl] [zones..]
args := c.RemainingArgs()
if len(args) > 0 {
// first args may be just a number, then it is the ttl, if not it is a zone
ttl, err := strconv.Atoi(args[0])
if err == nil {
// Reserve 0 (and smaller for future things)
if ttl <= 0 {
return nil, fmt.Errorf("cache TTL can not be zero or negative: %d", ttl)
}
ca.pttl = time.Duration(ttl) * time.Second
ca.nttl = time.Duration(ttl) * time.Second
args = args[1:]
}
}
origins := plugin.OriginsFromArgsOrServerBlock(args, c.ServerBlockKeys)
// Refinements? In an extra block.
for c.NextBlock() {
switch c.Val() {
// first number is cap, second is an new ttl
case Success:
args := c.RemainingArgs()
if len(args) == 0 {
return nil, c.ArgErr()
}
pcap, err := strconv.Atoi(args[0])
if err != nil {
return nil, err
}
ca.pcap = pcap
if len(args) > 1 {
pttl, err := strconv.Atoi(args[1])
if err != nil {
return nil, err
}
// Reserve 0 (and smaller for future things)
if pttl <= 0 {
return nil, fmt.Errorf("cache TTL can not be zero or negative: %d", pttl)
}
ca.pttl = time.Duration(pttl) * time.Second
if len(args) > 2 {
minpttl, err := strconv.Atoi(args[2])
if err != nil {
return nil, err
}
// Reserve < 0
if minpttl < 0 {
return nil, fmt.Errorf("cache min TTL can not be negative: %d", minpttl)
}
ca.minpttl = time.Duration(minpttl) * time.Second
}
}
case Denial:
args := c.RemainingArgs()
if len(args) == 0 {
return nil, c.ArgErr()
}
ncap, err := strconv.Atoi(args[0])
if err != nil {
return nil, err
}
ca.ncap = ncap
if len(args) > 1 {
nttl, err := strconv.Atoi(args[1])
if err != nil {
return nil, err
}
// Reserve 0 (and smaller for future things)
if nttl <= 0 {
return nil, fmt.Errorf("cache TTL can not be zero or negative: %d", nttl)
}
ca.nttl = time.Duration(nttl) * time.Second
if len(args) > 2 {
minnttl, err := strconv.Atoi(args[2])
if err != nil {
return nil, err
}
// Reserve < 0
if minnttl < 0 {
return nil, fmt.Errorf("cache min TTL can not be negative: %d", minnttl)
}
ca.minnttl = time.Duration(minnttl) * time.Second
}
}
case "prefetch":
args := c.RemainingArgs()
if len(args) == 0 || len(args) > 3 {
return nil, c.ArgErr()
}
amount, err := strconv.Atoi(args[0])
if err != nil {
return nil, err
}
if amount < 0 {
return nil, fmt.Errorf("prefetch amount should be positive: %d", amount)
}
ca.prefetch = amount
if len(args) > 1 {
dur, err := time.ParseDuration(args[1])
if err != nil {
return nil, err
}
ca.duration = dur
}
if len(args) > 2 {
pct := args[2]
if x := pct[len(pct)-1]; x != '%' {
return nil, fmt.Errorf("last character of percentage should be `%%`, but is: %q", x)
}
pct = pct[:len(pct)-1]
num, err := strconv.Atoi(pct)
if err != nil {
return nil, err
}
if num < 10 || num > 90 {
return nil, fmt.Errorf("percentage should fall in range [10, 90]: %d", num)
}
ca.percentage = num
}
case "serve_stale":
args := c.RemainingArgs()
if len(args) > 2 {
return nil, c.ArgErr()
}
ca.staleUpTo = 1 * time.Hour
if len(args) > 0 {
d, err := time.ParseDuration(args[0])
if err != nil {
return nil, err
}
if d < 0 {
return nil, errors.New("invalid negative duration for serve_stale")
}
ca.staleUpTo = d
}
ca.verifyStale = false
if len(args) > 1 {
mode := strings.ToLower(args[1])
if mode != "immediate" && mode != "verify" {
return nil, fmt.Errorf("invalid value for serve_stale refresh mode: %s", mode)
}
ca.verifyStale = mode == "verify"
}
case "servfail":
args := c.RemainingArgs()
if len(args) != 1 {
return nil, c.ArgErr()
}
d, err := time.ParseDuration(args[0])
if err != nil {
return nil, err
}
if d < 0 {
return nil, errors.New("invalid negative ttl for servfail")
}
if d > 5*time.Minute {
// RFC 2308 prohibits caching SERVFAIL longer than 5 minutes
return nil, errors.New("caching SERVFAIL responses over 5 minutes is not permitted")
}
ca.failttl = d
case "disable":
// disable [success|denial] [zones]...
args := c.RemainingArgs()
if len(args) < 1 {
return nil, c.ArgErr()
}
var zones []string
if len(args) > 1 {
for _, z := range args[1:] { // args[1:] define the list of zones to disable
nz := plugin.Name(z).Normalize()
if nz == "" {
return nil, fmt.Errorf("invalid disabled zone: %s", z)
}
zones = append(zones, nz)
}
} else {
// if no zones specified, default to root
zones = []string{"."}
}
switch args[0] { // args[0] defines which cache to disable
case Denial:
ca.nexcept = zones
case Success:
ca.pexcept = zones
default:
return nil, fmt.Errorf("cache type for disable must be %q or %q", Success, Denial)
}
case "keepttl":
args := c.RemainingArgs()
if len(args) != 0 {
return nil, c.ArgErr()
}
ca.keepttl = true
default:
return nil, c.ArgErr()
}
}
ca.Zones = origins
ca.zonesMetricLabel = strings.Join(origins, ",")
ca.pcache = cache.New(ca.pcap)
ca.ncache = cache.New(ca.ncap)
}
return ca, nil
}