Added dump and apply commands to provide JSON I/O

cmd/hostess/hostess.go

@@ -1,9 +1,10 @@
 package main
 
 import (
+	"os"
+
 	"github.com/cbednarski/hostess"
 	"github.com/codegangsta/cli"
-	"os"
 )
 
 func getCommand() string {
@@ -111,7 +112,7 @@ func main() {
 		},
 		{
 			Name:   "apply",
-			Usage:  "apply a JSON hosts dict to your hosts file",
+			Usage:  "add hostnames from a JSON file to the hosts file",
 			Action: hostess.Apply,
 			Flags:  app.Flags,
 		},

commands.go

@@ -3,9 +3,11 @@ package hostess
 import (
 	"bytes"
 	"fmt"
-	"github.com/codegangsta/cli"
+	"io/ioutil"
 	"os"
 	"strings"
+
+	"github.com/codegangsta/cli"
 )
 
 // ErrCantWriteHostFile indicates that we are unable to write to the hosts file
@@ -231,10 +233,32 @@ func Fix(c *cli.Context) {
 
 // Dump command outputs hosts file contents as JSON
 func Dump(c *cli.Context) {
-
+	hostsfile := AlwaysLoadHostFile(c)
+	output, err := hostsfile.Hosts.Dump()
+	if err != nil {
+		MaybeError(c, err.Error())
+	}
+	fmt.Println(fmt.Sprintf("%s", output))
 }
 
 // Apply command adds hostnames to the hosts file from JSON
 func Apply(c *cli.Context) {
+	if len(c.Args()) != 1 {
+		MaybeError(c, "Usage should be apply [filename]")
+	}
+	filename := c.Args()[0]
+
+	data, err := ioutil.ReadFile(filename)
+	if err != nil {
+		MaybeError(c, fmt.Sprintf("Unable to read %s: %s", filename, err))
+	}
+
+	hostfile := AlwaysLoadHostFile(c)
+	err = hostfile.Hosts.Apply(data)
+	if err != nil {
+		MaybeError(c, fmt.Sprintf("Error applying changes to hosts file: %s", err))
+	}
 
+	MaybeSaveHostFile(c, hostfile)
+	MaybePrintln(c, fmt.Sprintf("%s applied", filename))
 }

hostlist.go

@@ -1,6 +1,7 @@
 package hostess
 
 import (
+	"encoding/json"
 	"errors"
 	"fmt"
 	"net"
@@ -411,3 +412,23 @@ func (h *Hostlist) Format() []byte {
 
 	return out
 }
+
+// Dump exports all entries in the Hostlist as JSON
+func (h *Hostlist) Dump() ([]byte, error) {
+	return json.MarshalIndent(h, "", "  ")
+}
+
+// Apply imports all entries from the JSON input to this Hostlist
+func (h *Hostlist) Apply(data []byte) error {
+	var hostnames Hostlist
+	err := json.Unmarshal(data, &hostnames)
+	if err != nil {
+		return err
+	}
+
+	for _, hostname := range hostnames {
+		h.Add(hostname)
+	}
+
+	return nil
+}

hostlist_test.go

@@ -1,10 +1,12 @@
 package hostess_test
 
 import (
+	"bytes"
 	"fmt"
-	"github.com/cbednarski/hostess"
 	"net"
 	"testing"
+
+	"github.com/cbednarski/hostess"
 )
 
 func TestAddDuplicate(t *testing.T) {
@@ -197,3 +199,50 @@ func ExampleHostlist_1() {
 	// # 127.0.0.1 google.com
 	// ::1 google.com
 }
+
+const hostsjson = `[
+  {
+    "domain": "google.com",
+    "ip": "127.0.0.1",
+    "enabled": false
+  },
+  {
+    "domain": "google.com",
+    "ip": "::1",
+    "enabled": true
+  }
+]`
+
+func TestDump(t *testing.T) {
+	hosts := hostess.NewHostlist()
+	hosts.Add(hostess.NewHostname("google.com", "127.0.0.1", false))
+	hosts.Add(hostess.NewHostname("google.com", "::1", true))
+
+	expected := []byte(hostsjson)
+	actual, _ := hosts.Dump()
+
+	if !bytes.Equal(actual, expected) {
+		t.Errorf("JSON output did not match expected output: %s", Diff(string(expected), string(actual)))
+	}
+
+}
+
+func TestApply(t *testing.T) {
+	hosts := hostess.NewHostlist()
+	hosts.Apply([]byte(hostsjson))
+
+	hostnameA := hostess.NewHostname("google.com", "127.0.0.1", false)
+	if !hosts.Contains(hostnameA) {
+		t.Errorf("Expected to find %s", hostnameA.Format())
+	}
+
+	hostnameB := hostess.NewHostname("google.com", "::1", true)
+	if !hosts.Contains(hostnameB) {
+		t.Errorf("Expected to find %s", hostnameB.Format())
+	}
+
+	hosts.Apply([]byte(hostsjson))
+	if hosts.Len() != 2 {
+		t.Error("Hostslist contains the wrong number of items, expected 2")
+	}
+}

hostname.go

@@ -33,10 +33,10 @@ func LooksLikeIPv6(ip string) bool {
 // can cause unexpected behavior. Instead, use Hostlist's Add, Remove, Enable,
 // and Disable methods.
 type Hostname struct {
-	Domain  string
-	IP      net.IP
-	Enabled bool
-	IPv6    bool
+	Domain  string `json:"domain"`
+	IP      net.IP `json:"ip"`
+	Enabled bool   `json:"enabled"`
+	IPv6    bool   `json:"-"`
 }
 
 // NewHostname creates a new Hostname struct and automatically sets the IPv6