cmd/resolver: implement command to delete record on hosts file

The command has the following signature,

      resolver hosts.d rr delete <name> <domain>

Given the hosts name "hosts" and domain "my.hosts" it will delete
all records that have domain name "my.hosts" inside the file.

8 files changed, 101 insertions, 5 deletions

diff --git a/_doc/resolver.adoc b/_doc/resolver.adoc
index f0d40de..9951ad5 100644
--- a/_doc/resolver.adoc
+++ b/_doc/resolver.adoc
@@ -181,6 +181,13 @@ instead of replaced.
 --
 
 
+hosts.d rr delete <name> <domain>::
++
+--
+Delete record from hosts file "name" by domain name.
+--
+
+
 == EXIT STATUS
 
 Upon exit and success +resolver+ will return 0, or 1 otherwise.
@@ -188,6 +195,8 @@ Upon exit and success +resolver+ will return 0, or 1 otherwise.
 
 == EXAMPLES
 
+===  QUERY EXAMPLES
+
 Query the IPv4 address for kilabit.info,
 
 	$ resolver query kilabit.info
@@ -215,6 +224,9 @@ Inspect the rescached's caches on server at http://127.0.0.1:5380,
 
 	$ resolver -server=http://127.0.0.1:5380 caches
 
+
+===  MANAGING CACHES
+
 Search caches that contains "bit" on the domain name,
 
 	$ resolver caches search bit
@@ -227,6 +239,9 @@ Remove all caches in the server,
 
 	$ resolver caches remove all
 
+
+===  MANAGING ENVIRONMENT
+
 Fetch and print current server environment,
 
 	$ resolver env
@@ -239,6 +254,9 @@ Update the server environment by reading JSON from standard input,
 
 	$ cat /tmp/env.json | resolver env update -
 
+
+===  MANAGING HOSTS.D
+
 Create new hosts file named "myhosts" inside the hosts.d directory,
 
 	$ resolver hosts.d create myhosts
@@ -269,6 +287,8 @@ Get the content of hosts file named "myhosts" inside the hosts.d directory,
 	  }
 	]
 
+===  MANAGING RECORD ON HOSTS.D
+
 Add new record "127.0.0.1 my.hosts" to hosts file named "hosts",
 
 	$ resolver hosts.d rr add hosts my.hosts 127.0.0.1
@@ -280,6 +300,16 @@ Add new record "127.0.0.1 my.hosts" to hosts file named "hosts",
 	  "TTL": 604800
 	}
 
+Delete record "my.hosts" from hosts file "hosts",
+
+	$ resolver hosts.d rr delete hosts my.hosts
+	{
+	  "Value": "127.0.0.1",
+	  "Name": "my.hosts",
+	  "Type": 1,
+	  "Class": 1,
+	  "TTL": 604800
+	}
 
 == AUTHOR
 
diff --git a/_sys/usr/share/man/man1/resolver.1.gz b/_sys/usr/share/man/man1/resolver.1.gz
index 61dc96c..5a6d304 100644
--- a/_sys/usr/share/man/man1/resolver.1.gz
+++ b/_sys/usr/share/man/man1/resolver.1.gz
diff --git a/client.go b/client.go
index cc4399e..49f6a12 100644
--- a/client.go
+++ b/client.go
@@ -380,3 +380,34 @@ func (cl *Client) HostsdRecordAdd(hostsName, domain, value string) (record *dns.
 
 	return record, nil
 }
+
+// HostsdRecordDelete delete a record from hosts file by domain name.
+func (cl *Client) HostsdRecordDelete(hostsName, domain string) (record *dns.ResourceRecord, err error) {
+	var (
+		logp = "HostsdRecordDelete"
+		res  = libhttp.EndpointResponse{
+			Data: &record,
+		}
+		params = url.Values{}
+
+		resb []byte
+	)
+
+	params.Set(paramNameName, hostsName)
+	params.Set(paramNameDomain, domain)
+
+	_, resb, err = cl.Delete(apiHostsdRR, nil, params)
+	if err != nil {
+		return nil, fmt.Errorf("%s: %w", logp, err)
+	}
+
+	err = json.Unmarshal(resb, &res)
+	if err != nil {
+		return nil, fmt.Errorf("%s: %w", logp, err)
+	}
+	if res.Code != http.StatusOK {
+		return nil, fmt.Errorf("%s: %d %s", logp, res.Code, res.Message)
+	}
+
+	return record, nil
+}
diff --git a/cmd/resolver/main.go b/cmd/resolver/main.go
index 2c40b90..fac894c 100644
--- a/cmd/resolver/main.go
+++ b/cmd/resolver/main.go
@@ -206,6 +206,10 @@ hosts.d rr add <name> <domain> <value>
 	If the domain name already exists, the new record will be appended
 	instead of replaced.
 
+hosts.d rr delete <name> <domain>
+
+	Delete record from hosts file "name" by domain name.
+
 
 ==  Examples
 
@@ -299,5 +303,16 @@ Add new record "127.0.0.1 my.hosts" to hosts file named "hosts",
 	  "Type": 1,
 	  "Class": 1,
 	  "TTL": 604800
+	}
+
+Delete record "my.hosts" from hosts file "hosts",
+
+	$ resolver hosts.d rr delete hosts my.hosts
+	{
+	  "Value": "127.0.0.1",
+	  "Name": "my.hosts",
+	  "Type": 1,
+	  "Class": 1,
+	  "TTL": 604800
 	}`)
 }
diff --git a/cmd/resolver/resolver.go b/cmd/resolver/resolver.go
index 62ce953..792f8d9 100644
--- a/cmd/resolver/resolver.go
+++ b/cmd/resolver/resolver.go
@@ -362,6 +362,24 @@ func (rsol *resolver) doCmdHostsdRecord(args []string) {
 		fmt.Println(string(jsonb))
 
 	case subCmdDelete:
+		args = args[1:]
+		if len(args) <= 1 {
+			log.Fatalf("resolver: %s %s: missing arguments", rsol.cmd, subCmd)
+		}
+
+		resc = rsol.newRescachedClient()
+		record, err = resc.HostsdRecordDelete(args[0], args[1])
+		if err != nil {
+			log.Fatalf("resolver: %s", err)
+		}
+
+		jsonb, err = json.MarshalIndent(record, "", "  ")
+		if err != nil {
+			log.Fatalf("resolver: %s", err)
+		}
+
+		fmt.Println(string(jsonb))
+
 	default:
 		log.Fatalf("resolver: %s %s: unknown command %s", rsol.cmd, subCmdRR, subCmd)
 	}
diff --git a/go.mod b/go.mod
index 054bdf7..b9bdfd8 100644
--- a/go.mod
+++ b/go.mod
@@ -5,6 +5,6 @@ module github.com/shuLhan/rescached-go/v4
 
 go 1.16
 
-require github.com/shuLhan/share v0.36.1-0.20220418175009-e5c85cdbfb18
+require github.com/shuLhan/share v0.37.1-0.20220512163842-15f02872a61e
 
 //replace github.com/shuLhan/share => ../share
diff --git a/go.sum b/go.sum
index c6d95c1..09149c9 100644
--- a/go.sum
+++ b/go.sum
@@ -1,5 +1,5 @@
-github.com/shuLhan/share v0.36.1-0.20220418175009-e5c85cdbfb18 h1:kC1DQeauBOs830pBOx0oD7u4WWdV74dpy1/QR3kPNqE=
-github.com/shuLhan/share v0.36.1-0.20220418175009-e5c85cdbfb18/go.mod h1:laKGR1DNboj8+INRIC9VFYRiVEu/IIjrLurUmTHXkw0=
+github.com/shuLhan/share v0.37.1-0.20220512163842-15f02872a61e h1:1EyRREadyiHwpNsz8z0YUFQ5ifGbiXG9nBg1JitnL7M=
+github.com/shuLhan/share v0.37.1-0.20220512163842-15f02872a61e/go.mod h1:laKGR1DNboj8+INRIC9VFYRiVEu/IIjrLurUmTHXkw0=
 golang.org/x/crypto v0.0.0-20220131195533-30dcbda58838/go.mod h1:IxCIyHEi3zRg3s0A5j5BB6A9Jmi73HwBIUl50j+osU4=
 golang.org/x/net v0.0.0-20211112202133-69e39bad7dc2/go.mod h1:9nx3DQGgdP8bBQD5qxJ1jj9UTztislL4KSBs9R2vV5Y=
 golang.org/x/net v0.0.0-20220127200216-cd36cc0744dd h1:O7DYs+zxREGLKzKoMQrtrEacpb0ZVXA5rIwylE2Xchk=
diff --git a/httpd.go b/httpd.go
index e336307..4ae5a60 100644
--- a/httpd.go
+++ b/httpd.go
@@ -915,6 +915,7 @@ func (srv *Server) apiHostsdRecordDelete(epr *libhttp.EndpointRequest) (resbody
 		domainName    = epr.HttpRequest.Form.Get(paramNameDomain)
 
 		hfile *dns.HostsFile
+		rr    *dns.ResourceRecord
 		found bool
 	)
 
@@ -935,8 +936,8 @@ func (srv *Server) apiHostsdRecordDelete(epr *libhttp.EndpointRequest) (resbody
 		return nil, &res
 	}
 
-	found = hfile.RemoveRecord(domainName)
-	if !found {
+	rr = hfile.RemoveRecord(domainName)
+	if rr == nil {
 		res.Message = "unknown domain name: " + domainName
 		return nil, &res
 	}
@@ -951,6 +952,7 @@ func (srv *Server) apiHostsdRecordDelete(epr *libhttp.EndpointRequest) (resbody
 
 	res.Code = http.StatusOK
 	res.Message = "domain name '" + domainName + "' has been removed from hosts file"
+	res.Data = rr
 
 	return json.Marshal(&res)
 }