add host file support

Author: songrgg

README.md

@@ -12,13 +12,44 @@ extra costs to create a process, the second one means faster and less resource a
 and public key to authenticate.
 
 ## Usages
+
+### Use ssh command to access host1 and host2 running ls.
 ```bash
-// Use ssh command to access host1 and host2 running ls.
 $ llsh --hosts hosts1,hosts2 \
  --user sojiang \
  -c "ls"
+```
+
+### Use host file
+Hhost file is INI-like file, the format is like this, file name can be `test.hosts`
+```ini
+host1
+host2
+
+[app]
+app1
+app2
+
+[web]
+web1
+web2
 ``` 
 
+If you want to run `ls` on all of the servers, 
+```bash
+$ llsh --host_file test.hosts \
+ --user sojiang \
+ -c "ls"
+```
+
+If you only want to manipulate app section, it will choose only `app1` and `app2`
+```bash
+$ llsh --host_file test.hosts \
+ --section app \
+ --user sojiang \
+ -c "ls"
+```
+
 ### Help
 ```bash
 $ llsh --help
@@ -30,9 +61,11 @@ Usage:
 Flags:
   -c, --command string            The command you need to run on the servers
   -h, --help                      help for llsh
+      --host_file string          The path of host file, the content should be hosts separated by new line, if specified, hosts will be omitted
       --hosts string              The host names for remote server, split by comma, for example, host1,host2,host3
   -p, --password                  If we need to input password from terminal
   -k, --publickey string          The file path of the public key, like ~/.ssh/id_rsa.pub
+      --section string            The section of the host_file, default to all hosts when not specified or empty
       --ssh_command_path string   The file path of the ssh command, like /bin/ssh (default "ssh")
       --use_ssh_command           Use the ssh executable, like /bin/ssh (default true)
   -u, --user string               The username for login user

go.mod

@@ -7,4 +7,5 @@ require (
 	github.com/mattn/go-colorable v0.1.2 // indirect
 	github.com/spf13/cobra v0.0.5
 	golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9
+	gopkg.in/ini.v1 v1.47.0
 )

go.sum

@@ -40,4 +40,6 @@ golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223 h1:DH4skfRX4EBpamg7iV4ZlCpbl
 golang.org/x/sys v0.0.0-20190222072716-a9d3bda3a223/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/ini.v1 v1.47.0 h1:XAVsOWcIxjm6JVEbCbSZgSBZIF0BrCzXs4orAQr6uc8=
+gopkg.in/ini.v1 v1.47.0/go.mod h1:pNLf8WUiyNEtQjuu5G5vTm06TEv9tsIgeAvK8hOrP4k=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=

pkg/llsh/cmd/cmd.go

@@ -3,9 +3,12 @@ package cmd
 import (
 	"fmt"
 	"io/ioutil"
+	"os"
 	"strings"
 	"sync"
 
+	"gopkg.in/ini.v1"
+
 	"github.com/fatih/color"
 	"github.com/songrgg/llsh/pkg/helper"
 	"github.com/songrgg/llsh/pkg/ssh"
@@ -15,6 +18,8 @@ import (
 type options struct {
 	Command        string
 	Hosts          string
+	HostFile       string
+	Section        string
 	User           string
 	UseSSHCommand  bool
 	UsePassword    bool
@@ -43,6 +48,10 @@ func NewLLSHCommand() *cobra.Command {
 
 	cmds.PersistentFlags().StringVar(&options.Hosts, "hosts", "",
 		"The host names for remote server, split by comma, for example, host1,host2,host3")
+	cmds.PersistentFlags().StringVar(&options.HostFile, "host_file", "",
+		"The path of host file, the content should be hosts separated by new line, if specified, hosts will be omitted")
+	cmds.PersistentFlags().StringVar(&options.Section, "section", "",
+		"The section of the host_file, default to all hosts when not specified or empty")
 	cmds.PersistentFlags().StringVarP(&options.User, "user", "u", "",
 		"The username for login user")
 	cmds.PersistentFlags().StringVarP(&options.Command, "command", "c", "",
@@ -86,10 +95,55 @@ func (o *options) authMethods() []ssh.AuthMethod {
 	return authMethods
 }
 
+func (o *options) hosts() ([]string, error) {
+	if o.HostFile != "" {
+		//cfg, err := ini.Load(o.HostFile)
+		cfg, err := ini.LoadSources(ini.LoadOptions{SkipUnrecognizableLines: true}, o.HostFile)
+		if err != nil {
+			return nil, err
+		}
+
+		cfg, err = ini.LoadSources(ini.LoadOptions{
+			UnparseableSections: cfg.SectionStrings(),
+		}, o.HostFile)
+		if err != nil {
+			return nil, err
+		}
+
+		// Set to all roles which is the ini `DEFAULT` section.
+		var hosts []string
+		var sections []*ini.Section
+		if o.Section == "" {
+			sections = cfg.Sections()
+		} else {
+			sec, err := cfg.GetSection(o.Section)
+			if err != nil {
+				return nil, err
+			}
+			sections = append(sections, sec)
+		}
+
+		for _, sec := range sections {
+			for _, host := range strings.Split(string(sec.Body()), "\n") {
+				if h := strings.Trim(host, " "); h != "" {
+					hosts = append(hosts, h)
+				}
+			}
+		}
+		return hosts, nil
+	}
+	return strings.Split(o.Hosts, ","), nil
+}
+
 func (o *options) run() {
 	authMethods := o.authMethods()
 
-	hosts := strings.Split(o.Hosts, ",")
+	hosts, err := o.hosts()
+	if err != nil {
+		color.Red("Invalid hosts: %v", err)
+		os.Exit(1)
+	}
+
 	var wg sync.WaitGroup
 	var results []sshResult
 	var lock = sync.Mutex{}
@@ -134,7 +188,7 @@ func (o *options) run() {
 }
 
 func (o *options) validate() {
-	if o.Hosts == "" {
+	if o.HostFile == "" && o.Hosts == "" {
 		helper.Errorlq("hosts can't be empty")
 	}