[project] init

.dockerignore

@@ -0,0 +1,4 @@
+!src
+!cmd
+!go.mod
+!go.sum

.gitignore

@@ -0,0 +1,25 @@
+# If you prefer the allow list template instead of the deny list, see community template:
+# https://github.com/github/gitignore/blob/main/community/Golang/Go.AllowList.gitignore
+#
+# Binaries for programs and plugins
+*.exe
+*.exe~
+*.dll
+*.so
+*.dylib
+
+# Test binary, built with `go test -c`
+*.test
+
+# Output of the go coverage tool, specifically when used with LiteIDE
+*.out
+
+# Dependency directories (remove the comment below to include it)
+# vendor/
+
+# Go workspace file
+go.work
+go.work.sum
+
+# env file
+.env

Dockerfile

@@ -0,0 +1,18 @@
+FROM golang:1.22-alpine as builder
+
+# build app
+WORKDIR /opt/serverchecker/src
+COPY . /opt/serverchecker/src
+
+RUN go build -o /opt/serverchecker/serverchecker cmd/main.go
+RUN chmod a+x /opt/serverchecker/serverchecker
+
+# target image
+FROM golang:1.22-alpine
+RUN mkdir -p /opt/serverchecker
+
+COPY --from=builder /opt/serverchecker/serverchecker /opt/serverchecker/serverchecker
+RUN crontab -l | { cat; echo "0 * * * * /opt/serverchecker/serverchecker"; } | crontab -
+
+
+CMD ["crond", "-f", "-l", "2"]

cmd/main.go

@@ -0,0 +1,15 @@
+package main
+
+import (
+	"git.domandoman.xyz/doman/serverchecker/src"
+)
+
+func main() {
+	config, err := src.GetConfig()
+
+	if err != nil {
+		panic(err)
+	}
+
+	src.RunCheck(config)
+}

docker-compose.yaml

@@ -0,0 +1,9 @@
+services:
+  app:
+    image: serverchecker
+    restart: unless-stopped
+    build:
+      context: .
+      dockerfile: Dockerfile
+    env_file:
+      - .env

env.template

@@ -0,0 +1,4 @@
+DISCORD_TOKEN=""
+DISCORD_CHANNEL_ID=""
+CHECK_DOMAINS="[\"google.com\"]"
+CHECK_NOTIFY_EXPIRATION_DAYS=7

go.mod

@@ -0,0 +1,15 @@
+module git.domandoman.xyz/doman/serverchecker
+
+go 1.22.5
+
+require (
+	git.domandoman.xyz/doman/certchecker v0.0.2
+	github.com/bwmarrin/discordgo v0.28.1
+	github.com/joho/godotenv v1.5.1
+)
+
+require (
+	github.com/gorilla/websocket v1.4.2 // indirect
+	golang.org/x/crypto v0.0.0-20210421170649-83a5a9bb288b // indirect
+	golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 // indirect
+)

go.sum

@@ -0,0 +1,16 @@
+git.domandoman.xyz/doman/certchecker v0.0.2 h1:ems0cG8ULb/mSabkrsvTixXhHcZMiHrGggo4UeyOjY0=
+git.domandoman.xyz/doman/certchecker v0.0.2/go.mod h1:Ovlm5r/JfAr4LewAvXVDax6TnzBN8GwglTcYCJaWnzQ=
+github.com/bwmarrin/discordgo v0.28.1 h1:gXsuo2GBO7NbR6uqmrrBDplPUx2T3nzu775q/Rd1aG4=
+github.com/bwmarrin/discordgo v0.28.1/go.mod h1:NJZpH+1AfhIcyQsPeuBKsUtYrRnjkyu0kIVMCHkZtRY=
+github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
+github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
+github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
+golang.org/x/crypto v0.0.0-20210421170649-83a5a9bb288b h1:7mWr3k41Qtv8XlltBkDkl8LoP3mpSgBW8BUoxtEdbXg=
+golang.org/x/crypto v0.0.0-20210421170649-83a5a9bb288b/go.mod h1:T9bdIzuCu7OtxOm1hfPfRQxPLYneinmdGuTeoZ9dtd4=
+golang.org/x/net v0.0.0-20210226172049-e18ecbb05110/go.mod h1:m0MpNAwzfU5UDzcl9v0D8zg8gWTRqZa9RBIspLL5mdg=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68 h1:nxC68pudNYkKU6jWhgrqdreuFiOQWj1Fs7T3VrH4Pjw=
+golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
+golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

src/checker.go

@@ -0,0 +1,84 @@
+package src
+
+import (
+	"fmt"
+	"git.domandoman.xyz/doman/certchecker"
+	"strings"
+	"sync"
+	"time"
+)
+
+type Errors struct {
+	errors []error
+	mutex  sync.Mutex
+}
+
+func (errors *Errors) append(err error) {
+	errors.mutex.Lock()
+	errors.errors = append(errors.errors, err)
+	errors.mutex.Unlock()
+}
+
+func RunCheck(config *Config) {
+	localIp, err := getIp()
+
+	if err != nil {
+		panic(err)
+	}
+
+	wg := sync.WaitGroup{}
+	errors := Errors{}
+
+	for _, domain := range config.Domains {
+		wg.Add(2)
+
+		go func() {
+			defer wg.Done()
+
+			err := certchecker.Check(domain, config.NotifyExpirationDays)
+
+			if err != nil {
+				errors.append(fmt.Errorf("%s: %s", domain, err))
+			}
+		}()
+
+		go func() {
+			defer wg.Done()
+
+			domainIp, err := getDomainIp(domain)
+
+			if err != nil {
+				errors.append(fmt.Errorf("%s: %s", domain, err))
+			}
+
+			if domainIp != localIp {
+				errors.append(fmt.Errorf("%s: DNS mismatch (%s != %s)", domain, domainIp, localIp))
+			}
+		}()
+	}
+
+	wg.Wait()
+
+	if len(errors.errors) == 0 {
+		fmt.Println("No errors found")
+		return
+	}
+
+	builder := strings.Builder{}
+
+	header := fmt.Sprintf("@here\nDuring check at: %s several errors were found:\n", time.Now().Format(time.RFC3339))
+	builder.WriteString(header)
+
+	for _, err := range errors.errors {
+		builder.WriteString(err.Error())
+		builder.WriteString("\n")
+	}
+
+	message := builder.String()
+	fmt.Println(message)
+	err = sendDiscordMessage(config, message)
+
+	if err != nil {
+		panic(err)
+	}
+}

src/config.go

@@ -0,0 +1,40 @@
+package src
+
+import (
+	"encoding/json"
+	"github.com/joho/godotenv"
+	"os"
+	"strconv"
+)
+
+type Config struct {
+	Domains              []string
+	NotifyExpirationDays int
+	DiscordToken         string
+	DiscordChannelID     string
+}
+
+func GetConfig() (*Config, error) {
+	godotenv.Load()
+
+	domainsEncoded := os.Getenv("CHECK_DOMAINS")
+	domains := []string{}
+	err := json.Unmarshal([]byte(domainsEncoded), &domains)
+
+	if err != nil {
+		return nil, err
+	}
+
+	notifyExpirationDays, err := strconv.Atoi(os.Getenv("CHECK_NOTIFY_EXPIRATION_DAYS"))
+
+	if err != nil {
+		return nil, err
+	}
+
+	return &Config{
+		Domains:              domains,
+		NotifyExpirationDays: notifyExpirationDays,
+		DiscordToken:         os.Getenv("DISCORD_TOKEN"),
+		DiscordChannelID:     os.Getenv("DISCORD_CHANNEL_ID"),
+	}, nil
+}

src/discordInteraction.go

@@ -0,0 +1,26 @@
+package src
+
+import (
+	"github.com/bwmarrin/discordgo"
+)
+
+func sendDiscordMessage(config *Config, message string) error {
+	discord, err := discordgo.New("Bot " + config.DiscordToken)
+
+	if err != nil {
+		return err
+	}
+
+	err = discord.Open()
+	if err != nil {
+		return err
+	}
+
+	_, err = discord.ChannelMessageSend(config.DiscordChannelID, message)
+
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

src/ipTools.go

@@ -0,0 +1,38 @@
+package src
+
+import (
+	"encoding/json"
+	"io"
+	"net"
+	"net/http"
+)
+
+type IP struct {
+	Query string
+}
+
+func getIp() (string, error) {
+	req, err := http.Get("http://ip-api.com/json/")
+	if err != nil {
+		return "", err
+	}
+	defer req.Body.Close()
+
+	body, err := io.ReadAll(req.Body)
+	if err != nil {
+		return "", err
+	}
+
+	var ip IP
+	json.Unmarshal(body, &ip)
+
+	return ip.Query, nil
+}
+
+func getDomainIp(domain string) (string, error) {
+	ips, err := net.LookupIP(domain)
+	if err != nil {
+		return "", err
+	}
+	return ips[0].String(), nil
+}