initial version

8 files changed, 203 insertions, 0 deletions

diff --git a/check.go b/check.go
new file mode 100644
index 0000000..b011eba
--- /dev/null
+++ b/check.go
@@ -0,0 +1,31 @@
+package main
+
+import (
+	"bytes"
+	"context"
+	"log"
+	"os/exec"
+)
+
+type check struct {
+	Name   string
+	Plugin string
+	Args   []string
+}
+
+func (c check) execute(ctx context.Context) (string, int) {
+	cmd := exec.CommandContext(ctx, c.Plugin, c.Args...)
+
+	var bytes bytes.Buffer
+	cmd.Stdout = &bytes
+	cmd.Stderr = &bytes
+	log.Println(ctx)
+
+	if err := cmd.Run(); err != nil {
+		if ctx.Err() == context.DeadlineExceeded {
+			return "Check command timed out", critical
+		}
+	}
+
+	return bytes.String(), cmd.ProcessState.ExitCode()
+}
diff --git a/config.go b/config.go
new file mode 100644
index 0000000..b79e275
--- /dev/null
+++ b/config.go
@@ -0,0 +1,65 @@
+package main
+
+import (
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+)
+
+type config struct {
+	EmailTo       string
+	EmailFrom     string
+	SMTPServer    string `json:"omitempty"`
+	StateDir      string `json:"omitempty"`
+	CheckTimeoutS int
+	Checks        []check
+}
+
+func newConfig(configFile string) (config, error) {
+	var config config
+
+	// Open the file
+	file, err := os.Open(configFile)
+	if err != nil {
+		return config, err
+	}
+	defer file.Close()
+
+	// Read the file content
+	bytes, err := ioutil.ReadAll(file)
+	if err != nil {
+		return config, err
+	}
+
+	// Parse the JSON content
+	err = json.Unmarshal(bytes, &config)
+	if err != nil {
+		return config, err
+	}
+
+	if config.SMTPServer == "" {
+		hostname, err := os.Hostname()
+		if err != nil {
+			panic(err)
+		}
+		config.SMTPServer = fmt.Sprintf("%s:25", hostname)
+		log.Println("Set SMTPServer to " + config.SMTPServer)
+	}
+
+	if config.StateDir == "" {
+		config.StateDir = "."
+		log.Println("Set StateDir to " + config.StateDir)
+	}
+
+	dedup := make(map[string]interface{})
+	for _, check := range config.Checks {
+		if _, ok := dedup[check.Name]; ok {
+			return config, fmt.Errorf("Duplicate definition of check %s", check.Name)
+		}
+		dedup[check.Name] = struct{}{}
+	}
+
+	return config, nil
+}
diff --git a/exitcodes.go b/exitcodes.go
new file mode 100644
index 0000000..18e3e19
--- /dev/null
+++ b/exitcodes.go
@@ -0,0 +1,21 @@
+package main
+
+const (
+	ok       = 0
+	warning  = 1
+	critical = 2
+	unknown  = 3
+)
+
+func codeToString(state int) string {
+	switch state {
+	case 0:
+		return "OK"
+	case 1:
+		return "WARNING"
+	case 2:
+		return "CRITICAL"
+	default:
+		return "UNKNOWN"
+	}
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..e8c05ec
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module codeberg.org/snonux/gogios
+
+go 1.19
diff --git a/gogios.json b/gogios.json
new file mode 100644
index 0000000..2f2dbe0
--- /dev/null
+++ b/gogios.json
@@ -0,0 +1,17 @@
+{
+  "EmailTo": "paul",
+  "EmailFrom": "gogios@buetow.org",
+  "CheckTimeoutS": 10,
+  "Checks": [
+    {
+      "Name": "www.foo.zone HTTP IPv4",
+      "Plugin": "/usr/local/libexec/nagios/check_http",
+      "Args": ["www.foo.zone", "-4"]
+    },
+    {
+      "Name": "www.foo.zone HTTP IPv6",
+      "Plugin": "/usr/local/libexec/nagios/check_http",
+      "Args": ["www.foo.zone", "-6"]
+    }
+  ]
+}
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..cf63a5f
--- /dev/null
+++ b/main.go
@@ -0,0 +1,33 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"fmt"
+	"log"
+	"time"
+)
+
+func main() {
+	log.Println("Welcome to Gogios!")
+
+	configFile := flag.String("cfg", "/etc/gogios.json", "The config file")
+
+	flag.Parse()
+
+	config, err := newConfig(*configFile)
+	if err != nil {
+		panic(err)
+	}
+
+	for _, check := range config.Checks {
+		ctx, cancel := context.WithTimeout(context.Background(),
+			time.Duration(config.CheckTimeoutS)*time.Second)
+		defer cancel()
+
+		if output, status := check.execute(ctx); status != ok {
+			subject := fmt.Sprintf("GOGIOS %s: %s", codeToString(status), check.Name)
+			notify(config, subject, output)
+		}
+	}
+}
diff --git a/notify.go b/notify.go
new file mode 100644
index 0000000..c31a242
--- /dev/null
+++ b/notify.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"net/smtp"
+)
+
+func notify(config config, subject, body string) error {
+	log.Println("emailNotify", subject, body)
+
+	headers := make(map[string]string)
+	headers["From"] = config.EmailFrom
+	headers["To"] = config.EmailTo
+	headers["Subject"] = subject
+	headers["MIME-Version"] = "1.0"
+	headers["Content-Type"] = "text/plain; charset=\"utf-8\""
+
+	header := ""
+	for k, v := range headers {
+		header += fmt.Sprintf("%s: %s\r\n", k, v)
+	}
+
+	message := header + "\r\n" + body
+	log.Println("Using SMTP server", config.SMTPServer)
+	return smtp.SendMail(config.SMTPServer, nil, config.EmailFrom,
+		[]string{config.EmailTo}, []byte(message))
+}
diff --git a/state.go b/state.go
new file mode 100644
index 0000000..c3c7eab
--- /dev/null
+++ b/state.go
@@ -0,0 +1,5 @@
+package main
+
+type state struct {
+	Checks map[string]int
+}