all: refactoring the hosts blocks format and location

This changes add new directory called "block.d" under rescached.
This directory contains hosts file fetched from URL defined in hosts
block configuration.
In this way, we did not mixed between user created hosts file and
external hosts file.

In the configuration file, we changes the hosts block format from
single line

  hosts_block = <URL>

into subsection with dynamic name,

  [block.d "<name>"]
  name = <name>
  url = <URL>

1 files changed, 18 insertions, 34 deletions

diff --git a/httpd.go b/httpd.go
index 6e51ddf..17a8442 100644
--- a/httpd.go
+++ b/httpd.go
@@ -5,11 +5,9 @@ package rescached
 
 import (
 	"encoding/json"
-	"errors"
 	"fmt"
 	"log"
 	"net/http"
-	"os"
 	"path/filepath"
 	"regexp"
 	"strconv"
@@ -376,19 +374,17 @@ func (srv *Server) httpApiEnvironmentUpdate(epr *libhttp.EndpointRequest) (resBo
 	return json.Marshal(&res)
 }
 
-//
 // apiHostsBlockUpdate set the HostsBlock to be enabled or disabled.
 //
 // If its status changes to enabled, unhide the hosts block file, populate the
-// hosts back to caches, and add it to list of HostsFiles.
+// hosts back to caches, and add it to list of hostsBlocksFile.
 //
 // If its status changes to disabled, remove the hosts from caches, hide it,
-// and remove it from list of HostsFiles.
-//
+// and remove it from list of hostsBlocksFile.
 func (srv *Server) apiHostsBlockUpdate(epr *libhttp.EndpointRequest) (resBody []byte, err error) {
 	var (
 		res         = libhttp.EndpointResponse{}
-		hostsBlocks = make([]*hostsBlock, 0)
+		hostsBlocks = make(map[string]*hostsBlock, 0)
 
 		hbx *hostsBlock
 		hby *hostsBlock
@@ -444,39 +440,32 @@ func (srv *Server) apiHostsBlockUpdate(epr *libhttp.EndpointRequest) (resBody []
 
 func (srv *Server) hostsBlockEnable(hb *hostsBlock) (err error) {
 	var (
+		logp = "hostsBlockEnable"
+
 		hfile *dns.HostsFile
 	)
 
-	hb.IsEnabled = true
-
-	err = hb.unhide()
+	err = hb.enable()
 	if err != nil {
-		if !errors.Is(err, os.ErrNotExist) {
-			return err
-		}
-		// File not exist, fetch new from server.
-		err = hb.update()
-		if err != nil {
-			return err
-		}
+		return fmt.Errorf("%s: %w", logp, err)
 	}
 
-	hfile, err = dns.ParseHostsFile(filepath.Join(dirHosts, hb.Name))
+	err = hb.update()
 	if err != nil {
-		return err
+		return fmt.Errorf("%s: %w", logp, err)
 	}
 
-	err = srv.dns.PopulateCachesByRR(hfile.Records, hfile.Path)
+	hfile, err = dns.ParseHostsFile(hb.file)
 	if err != nil {
-		return err
+		return fmt.Errorf("%s: %w", logp, err)
 	}
 
-	err = hb.update()
+	err = srv.dns.PopulateCachesByRR(hfile.Records, hfile.Path)
 	if err != nil {
-		return err
+		return fmt.Errorf("%s: %w", logp, err)
 	}
 
-	srv.env.HostsFiles[hfile.Name] = hfile
+	srv.env.hostsBlocksFile[hfile.Name] = hfile
 
 	return nil
 }
@@ -488,18 +477,19 @@ func (srv *Server) hostsBlockDisable(hb *hostsBlock) (err error) {
 		hfile *dns.HostsFile
 	)
 
-	hfile = srv.env.HostsFiles[hb.Name]
+	hfile = srv.env.hostsBlocksFile[hb.Name]
 	if hfile == nil {
 		return fmt.Errorf("%s: unknown hosts block: %q", logp, hb.Name)
 	}
 
 	srv.dns.RemoveLocalCachesByNames(hfile.Names())
 
-	err = hb.hide()
+	err = hb.disable()
 	if err != nil {
 		return fmt.Errorf("%s: %w", logp, err)
 	}
-	delete(srv.env.HostsFiles, hb.Name)
+
+	delete(srv.env.hostsBlocksFile, hfile.Name)
 
 	return nil
 }
@@ -602,9 +592,7 @@ func (srv *Server) apiHostsFileDelete(epr *libhttp.EndpointRequest) (resbody []b
 	return json.Marshal(&res)
 }
 
-//
 // apiHostsFileRRCreate create new record and save it to the hosts file.
-//
 func (srv *Server) apiHostsFileRRCreate(epr *libhttp.EndpointRequest) (resbody []byte, err error) {
 	var (
 		res           = libhttp.EndpointResponse{}
@@ -806,9 +794,7 @@ func (srv *Server) apiZoneDelete(epr *libhttp.EndpointRequest) (resbody []byte,
 	return json.Marshal(&res)
 }
 
-//
 // apiZoneRRCreate create new RR for the zone file.
-//
 func (srv *Server) apiZoneRRCreate(epr *libhttp.EndpointRequest) (resbody []byte, err error) {
 	var (
 		res          = libhttp.EndpointResponse{}
@@ -908,9 +894,7 @@ func (srv *Server) apiZoneRRCreate(epr *libhttp.EndpointRequest) (resbody []byte
 	return json.Marshal(&res)
 }
 
-//
 // apiZoneRRDelete delete RR from the zone file.
-//
 func (srv *Server) apiZoneRRDelete(epr *libhttp.EndpointRequest) (resbody []byte, err error) {
 	var (
 		res          = libhttp.EndpointResponse{}