From dd0b8e3f38b2dc9f05296e7fe5c612d9e601c03f Mon Sep 17 00:00:00 2001
From: Ian Fijolek <ian@iamthefij.com>
Date: Tue, 1 Oct 2019 08:26:07 -0700
Subject: [PATCH] Added ability to run commands in a shell

Diverges a small amount from the Python version for this.
---
 alert.go   | 12 ++++++++++--
 config.go  |  2 ++
 monitor.go |  6 ++++--
 util.go    | 21 +++++++++++++++++++++
 4 files changed, 37 insertions(+), 4 deletions(-)

diff --git a/alert.go b/alert.go
index 3f998c6..04c63a0 100644
--- a/alert.go
+++ b/alert.go
@@ -1,7 +1,9 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
+	"log"
 	"os/exec"
 	"text/template"
 	"time"
@@ -12,7 +14,7 @@ type Alert struct {
 	Command              []string
 	CommandShell         string `yaml:"command_shell"`
 	commandTemplate      []template.Template
-	commandShellTemplate template.Template
+	commandShellTemplate *template.Template
 }
 
 func (alert Alert) IsValid() bool {
@@ -43,8 +45,14 @@ func (alert Alert) Send(notice AlertNotice) {
 	} else if alert.commandShellTemplate != nil {
 		var commandBuffer bytes.Buffer
 		err := alert.commandShellTemplate.Execute(&commandBuffer, notice)
-		// TODO handle error
+		if err != nil {
+			panic(err)
+		}
 		cmd = exec.Command(commandBuffer.String())
+
+		output, err := cmd.CombinedOutput()
+		log.Printf("Check %s\n---\n%s\n---", alert.Name, string(output))
+
 	} else {
 		panic("No template?")
 	}
diff --git a/config.go b/config.go
index b22bf10..9356a63 100644
--- a/config.go
+++ b/config.go
@@ -18,6 +18,8 @@ func LoadConfig(filePath string) (config Config) {
 	if err != nil {
 		panic(err)
 	}
+
+	// TODO: Decide if this is better expanded here, or only when executing
 	env_expanded := os.ExpandEnv(string(data))
 
 	err = yaml.Unmarshal([]byte(env_expanded), &config)
diff --git a/monitor.go b/monitor.go
index 9874994..cfa2546 100644
--- a/monitor.go
+++ b/monitor.go
@@ -10,7 +10,7 @@ type Monitor struct {
 	// Config values
 	Name          string
 	Command       []string
-	CommandShell  string   `yaml:"command_shell`
+	CommandShell  string   `yaml:"command_shell"`
 	AlertDown     []string `yaml:"alert_down"`
 	AlertUp       []string `yaml:"alert_up"`
 	CheckInterval float64  `yaml:"check_interval"`
@@ -45,7 +45,9 @@ func (monitor *Monitor) Check() bool {
 		cmd = exec.Command(monitor.Command[0], monitor.Command[1:]...)
 	} else {
 		// TODO: Handle a command shell as well. This is untested
-		cmd = exec.Command(monitor.CommandShell)
+
+		//cmd = exec.Command("sh", "-c", "echo \"This is a test of the command system\"")
+		cmd = ShellCommand(monitor.CommandShell)
 	}
 
 	output, err := cmd.CombinedOutput()
diff --git a/util.go b/util.go
index 1110061..787ac43 100644
--- a/util.go
+++ b/util.go
@@ -1,3 +1,24 @@
 package main
 
+import (
+	"log"
+	"os/exec"
+	"strings"
+)
 
+/// escapeCommandShell accepts a command to be executed by a shell and escapes it
+func escapeCommandShell(command string) string {
+	// Remove extra spaces and newlines from ends
+	command = strings.TrimSpace(command)
+	// TODO: Not sure if this part is actually needed. Should verify
+	// Escape double quotes since this will be passed in as an argument
+	command = strings.Replace(command, `"`, `\"`, -1)
+	return command
+}
+
+/// ShellCommand takes a string and executes it as a command using `sh`
+func ShellCommand(command string) *exec.Cmd {
+	shellCommand := []string{"sh", "-c", escapeCommandShell(command)}
+	log.Printf("Command: %v", shellCommand)
+	return exec.Command(shellCommand[0], shellCommand[1:]...)
+}