feat(cli): install agents via SSH on a custom port (#516)

To authenticate to the remote host on a non-standard SSH port
users can now use the `--ssh_port` flag or pass the port directly
via the argument:
```
$ lacework agent install <user@host:port>
```

JIRA: https://lacework.atlassian.net/browse/ALLY-602

Signed-off-by: Salim Afiune Maya <[email protected]>

cli/cmd/agent.go

@@ -37,6 +37,7 @@ var (
 		TokenUpdateDesc     string
 		InstallForce        bool
 		InstallSshUser      string
+		InstallSshPort      int
 		InstallAgentToken   string
 		InstallTrustHostKey bool
 		InstallPassword     string
@@ -136,7 +137,7 @@ To enable a token:
 	}
 
 	agentInstallCmd = &cobra.Command{
-		Use:   "install <[user@]host>",
+		Use:   "install <[user@]host[:port]>",
 		Short: "install the datacollector agent on a remote host",
 		Args:  cobra.ExactArgs(1),
 		Long: `For single host installation of the Lacework agent via Secure Shell (SSH).
@@ -156,6 +157,11 @@ To provide an agent access token of your choice, use the command 'lacework agent
 select a token and pass it to the '--token' flag.
 
     $ lacework agent install <user@host> -i /path/to/your/key --token <token>
+
+To authenticate to the remote host on a non-standard SSH port use the '--ssh_port' flag or
+pass it directly via the argument.
+
+    $ lacework agent install <user@host:port>
     `,
 		RunE: installRemoteAgent,
 	}
@@ -202,6 +208,9 @@ func init() {
 	agentInstallCmd.Flags().StringVar(&agentCmdState.InstallSshUser,
 		"ssh_username", "", "username to login with",
 	)
+	agentInstallCmd.Flags().IntVar(&agentCmdState.InstallSshPort,
+		"ssh_port", 22, "port to connect to on the remote host",
+	)
 	agentInstallCmd.Flags().BoolVar(&agentCmdState.InstallForce,
 		"force", false, "override any pre-installed agent",
 	)

cli/cmd/agent_install.go

@@ -22,6 +22,7 @@ import (
 	"bytes"
 	"fmt"
 	"net"
+	"strconv"
 	"strings"
 
 	"github.com/AlecAivazis/survey/v2"
@@ -39,19 +40,37 @@ const agentInstallDownloadURL = "https://packages.lacework.net/install.sh"
 func installRemoteAgent(_ *cobra.Command, args []string) error {
 	var (
 		user    = agentCmdState.InstallSshUser
+		port    = agentCmdState.InstallSshPort
 		host    = args[0]
 		authSet = false
 	)
-	// verify if the user specified the username via user@host
+
+	// verify if the user specified the username via "user@host"
 	if strings.Contains(host, "@") {
 		userHost := strings.Split(host, "@")
 		user = userHost[0]
 		host = userHost[1]
 	}
 
+	// verify if the user specified the port via "host:port"
+	if strings.Contains(host, ":") {
+		userHost := strings.Split(host, ":")
+		host = userHost[0]
+		p, err := strconv.Atoi(userHost[1])
+		if err != nil {
+			return errors.Wrap(err, "invalid port")
+		}
+		port = p
+	}
+
 	cli.Log.Debugw("creating runner", "user", user, "host", host)
 	runner := lwrunner.New(user, host, verifyHostCallback)
 
+	if runner.Port != port {
+		cli.Log.Debugw("ssh settings", "port", port)
+		runner.Port = port
+	}
+
 	if runner.User == "" {
 		cli.Log.Debugw("ssh username not set")
 		user, err := askForUsername()