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|
package proxy
import (
"fmt"
"net"
"strconv"
"sync/atomic"
"time"
"github.com/coredns/coredns/middleware"
"github.com/coredns/coredns/middleware/pkg/dnsutil"
"github.com/coredns/coredns/middleware/pkg/healthcheck"
"github.com/coredns/coredns/middleware/pkg/tls"
"github.com/mholt/caddy/caddyfile"
"github.com/miekg/dns"
)
type staticUpstream struct {
from string
healthcheck.HealthCheck
WithoutPathPrefix string
IgnoredSubDomains []string
ex Exchanger
}
// NewStaticUpstreams parses the configuration input and sets up
// static upstreams for the proxy middleware.
func NewStaticUpstreams(c *caddyfile.Dispenser) ([]Upstream, error) {
var upstreams []Upstream
for c.Next() {
upstream := &staticUpstream{
from: ".",
HealthCheck: healthcheck.HealthCheck{
FailTimeout: 10 * time.Second,
MaxFails: 1,
Future: 60 * time.Second,
},
ex: newDNSEx(),
}
if !c.Args(&upstream.from) {
return upstreams, c.ArgErr()
}
upstream.from = middleware.Host(upstream.from).Normalize()
to := c.RemainingArgs()
if len(to) == 0 {
return upstreams, c.ArgErr()
}
// process the host list, substituting in any nameservers in files
toHosts, err := dnsutil.ParseHostPortOrFile(to...)
if err != nil {
return upstreams, err
}
for c.NextBlock() {
if err := parseBlock(c, upstream); err != nil {
return upstreams, err
}
}
upstream.Hosts = make([]*healthcheck.UpstreamHost, len(toHosts))
for i, host := range toHosts {
uh := &healthcheck.UpstreamHost{
Name: host,
Conns: 0,
Fails: 0,
FailTimeout: upstream.FailTimeout,
CheckDown: func(upstream *staticUpstream) healthcheck.UpstreamHostDownFunc {
return func(uh *healthcheck.UpstreamHost) bool {
down := false
uh.CheckMu.Lock()
until := uh.OkUntil
uh.CheckMu.Unlock()
if !until.IsZero() && time.Now().After(until) {
down = true
}
fails := atomic.LoadInt32(&uh.Fails)
if fails >= upstream.MaxFails && upstream.MaxFails != 0 {
down = true
}
return down
}
}(upstream),
WithoutPathPrefix: upstream.WithoutPathPrefix,
}
upstream.Hosts[i] = uh
}
upstream.Start()
upstreams = append(upstreams, upstream)
}
return upstreams, nil
}
func (u *staticUpstream) From() string {
return u.from
}
func parseBlock(c *caddyfile.Dispenser, u *staticUpstream) error {
switch c.Val() {
case "policy":
if !c.NextArg() {
return c.ArgErr()
}
policyCreateFunc, ok := healthcheck.SupportedPolicies[c.Val()]
if !ok {
return c.ArgErr()
}
u.Policy = policyCreateFunc()
case "fail_timeout":
if !c.NextArg() {
return c.ArgErr()
}
dur, err := time.ParseDuration(c.Val())
if err != nil {
return err
}
u.FailTimeout = dur
case "max_fails":
if !c.NextArg() {
return c.ArgErr()
}
n, err := strconv.Atoi(c.Val())
if err != nil {
return err
}
u.MaxFails = int32(n)
case "health_check":
if !c.NextArg() {
return c.ArgErr()
}
var err error
u.HealthCheck.Path, u.HealthCheck.Port, err = net.SplitHostPort(c.Val())
if err != nil {
return err
}
u.HealthCheck.Interval = 30 * time.Second
if c.NextArg() {
dur, err := time.ParseDuration(c.Val())
if err != nil {
return err
}
u.HealthCheck.Interval = dur
u.Future = 2 * dur
// set a minimum of 3 seconds
if u.Future < (3 * time.Second) {
u.Future = 3 * time.Second
}
}
case "without":
if !c.NextArg() {
return c.ArgErr()
}
u.WithoutPathPrefix = c.Val()
case "except":
ignoredDomains := c.RemainingArgs()
if len(ignoredDomains) == 0 {
return c.ArgErr()
}
for i := 0; i < len(ignoredDomains); i++ {
ignoredDomains[i] = middleware.Host(ignoredDomains[i]).Normalize()
}
u.IgnoredSubDomains = ignoredDomains
case "spray":
u.Spray = &healthcheck.Spray{}
case "protocol":
encArgs := c.RemainingArgs()
if len(encArgs) == 0 {
return c.ArgErr()
}
switch encArgs[0] {
case "dns":
if len(encArgs) > 1 {
if encArgs[1] == "force_tcp" {
opts := Options{ForceTCP: true}
u.ex = newDNSExWithOption(opts)
} else {
return fmt.Errorf("only force_tcp allowed as parameter to dns")
}
} else {
u.ex = newDNSEx()
}
case "https_google":
boot := []string{"8.8.8.8:53", "8.8.4.4:53"}
if len(encArgs) > 2 && encArgs[1] == "bootstrap" {
boot = encArgs[2:]
}
u.ex = newGoogle("", boot) // "" for default in google.go
case "grpc":
if len(encArgs) == 2 && encArgs[1] == "insecure" {
u.ex = newGrpcClient(nil, u)
return nil
}
tls, err := tls.NewTLSConfigFromArgs(encArgs[1:]...)
if err != nil {
return err
}
u.ex = newGrpcClient(tls, u)
default:
return fmt.Errorf("%s: %s", errInvalidProtocol, encArgs[0])
}
default:
return c.Errf("unknown property '%s'", c.Val())
}
return nil
}
func (u *staticUpstream) IsAllowedDomain(name string) bool {
if dns.Name(name) == dns.Name(u.From()) {
return true
}
for _, ignoredSubDomain := range u.IgnoredSubDomains {
if middleware.Name(ignoredSubDomain).Matches(name) {
return false
}
}
return true
}
func (u *staticUpstream) Exchanger() Exchanger { return u.ex }
|
