all: rename Options to environment

While at it, unexport it.

1 files changed, 180 insertions, 0 deletions

diff --git a/environment.go b/environment.go
new file mode 100644
index 0000000..2cbe0e6
--- /dev/null
+++ b/environment.go
@@ -0,0 +1,180 @@
+// Copyright 2018, Shulhan <ms@kilabit.info>. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package rescached
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"strconv"
+
+	"github.com/shuLhan/share/lib/debug"
+	"github.com/shuLhan/share/lib/dns"
+	"github.com/shuLhan/share/lib/ini"
+	libnet "github.com/shuLhan/share/lib/net"
+	libstrings "github.com/shuLhan/share/lib/strings"
+)
+
+const (
+	defWuiAddress = "127.0.0.1:5380"
+)
+
+const (
+	sectionNameDNS       = "dns"
+	sectionNameRescached = "rescached"
+
+	subNameServer = "server"
+
+	keyDebug          = "debug"
+	keyFileResolvConf = "file.resolvconf"
+
+	keyCachePruneDelay     = "cache.prune_delay"
+	keyCachePruneThreshold = "cache.prune_threshold"
+	keyDohBehindProxy      = "doh.behind_proxy"
+	keyHTTPPort            = "http.port"
+	keyListen              = "listen"
+	keyParent              = "parent"
+	keyTLSAllowInsecure    = "tls.allow_insecure"
+	keyTLSCertificate      = "tls.certificate"
+	keyTLSPort             = "tls.port"
+	keyTLSPrivateKey       = "tls.private_key"
+)
+
+//
+// environment for running rescached.
+//
+type environment struct {
+	dns.ServerOptions
+	WuiListen      string `ini:"rescached::wui.listen"`
+	DirHosts       string `ini:"rescached::dir.hosts"`
+	DirMaster      string `ini:"rescached::dir.master"`
+	FileResolvConf string `ini:"rescached::file.resolvconf"`
+	Debug          int    `ini:"rescached::debug"`
+}
+
+func loadEnvironment(file string) (env *environment) {
+	env = newEnvironment()
+
+	if len(file) == 0 {
+		env.init()
+		return env
+	}
+
+	cfg, err := ioutil.ReadFile(file)
+	if err != nil {
+		log.Printf("rescached: loadEnvironment %q: %s", file, err)
+		return env
+	}
+
+	err = ini.Unmarshal(cfg, env)
+	if err != nil {
+		log.Printf("rescached: loadEnvironment %q: %s", file, err)
+		return env
+	}
+
+	env.init()
+	debug.Value = env.Debug
+
+	return env
+}
+
+//
+// newEnvironment create and initialize options with default values.
+//
+func newEnvironment() *environment {
+	return &environment{
+		ServerOptions: dns.ServerOptions{
+			ListenAddress: "127.0.0.1:53",
+		},
+	}
+}
+
+//
+// init check and initialize the environment instance with default values.
+//
+func (env *environment) init() {
+	if len(env.WuiListen) == 0 {
+		env.WuiListen = defWuiAddress
+	}
+	if len(env.ListenAddress) == 0 {
+		env.ListenAddress = "127.0.0.1:53"
+	}
+	if len(env.FileResolvConf) > 0 {
+		_, _ = env.loadResolvConf()
+	}
+}
+
+func (env *environment) loadResolvConf() (ok bool, err error) {
+	rc, err := libnet.NewResolvConf(env.FileResolvConf)
+	if err != nil {
+		return false, err
+	}
+
+	if debug.Value > 0 {
+		fmt.Printf("rescached: loadResolvConf: %+v\n", rc)
+	}
+
+	if len(rc.NameServers) == 0 {
+		return false, nil
+	}
+
+	for x := 0; x < len(rc.NameServers); x++ {
+		rc.NameServers[x] = "udp://" + rc.NameServers[x]
+	}
+
+	if libstrings.IsEqual(env.NameServers, rc.NameServers) {
+		return false, nil
+	}
+
+	if len(env.NameServers) == 0 {
+		env.NameServers = rc.NameServers
+	} else {
+		env.FallbackNS = rc.NameServers
+	}
+
+	return true, nil
+}
+
+//
+// write the options values back to file.
+//
+func (env *environment) write(file string) (err error) {
+	in, err := ini.Open(file)
+	if err != nil {
+		return fmt.Errorf("write: %w", err)
+	}
+
+	in.Set(sectionNameRescached, "", keyFileResolvConf, env.FileResolvConf)
+	in.Set(sectionNameRescached, "", keyDebug, strconv.Itoa(env.Debug))
+
+	in.UnsetAll(sectionNameDNS, subNameServer, keyParent)
+	for _, ns := range env.NameServers {
+		in.Add(sectionNameDNS, subNameServer, keyParent, ns)
+	}
+
+	in.Set(sectionNameDNS, subNameServer, keyListen,
+		env.ServerOptions.ListenAddress)
+
+	in.Set(sectionNameDNS, subNameServer, keyHTTPPort,
+		strconv.Itoa(int(env.ServerOptions.HTTPPort)))
+
+	in.Set(sectionNameDNS, subNameServer, keyTLSPort,
+		strconv.Itoa(int(env.ServerOptions.TLSPort)))
+	in.Set(sectionNameDNS, subNameServer, keyTLSCertificate,
+		env.ServerOptions.TLSCertFile)
+	in.Set(sectionNameDNS, subNameServer, keyTLSPrivateKey,
+		env.ServerOptions.TLSPrivateKey)
+	in.Set(sectionNameDNS, subNameServer, keyTLSAllowInsecure,
+		fmt.Sprintf("%t", env.ServerOptions.TLSAllowInsecure))
+	in.Set(sectionNameDNS, subNameServer, keyDohBehindProxy,
+		fmt.Sprintf("%t", env.ServerOptions.DoHBehindProxy))
+
+	in.Set(sectionNameDNS, subNameServer, keyCachePruneDelay,
+		fmt.Sprintf("%s", env.ServerOptions.PruneDelay))
+	in.Set(sectionNameDNS, subNameServer, keyCachePruneThreshold,
+		fmt.Sprintf("%s", env.ServerOptions.PruneThreshold))
+
+	return in.Save(file)
+}