├── .gitignore
├── README.md
├── bin
└── build
├── main.go
├── sample-env.sh
└── tests
└── test.html
/.gitignore:
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1 | /build/
2 |
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/README.md:
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1 | Mailgun mailing list API
2 | ========================
3 |
4 | A simple API, written in Go, for subscribing new emails to a Mailgun mailing list.
5 |
6 | Usage
7 | -----
8 |
9 | Set environment variables to configure the application:
10 |
11 | ```bash
12 | export MAILGUN_DOMAIN=mg.yourdomain.com
13 | export MAILGUN_API_KEY=key-abcdefghijkl
14 | export MAILGUN_MAILING_LIST=newsletter@mg.yourdomain.com
15 | export SUBSCRIBE_HTTP_PORT=8000
16 | export SUBSCRIBE_REDIRECT_URL=http://yourdomain.com/newsletter/success
17 | ```
18 |
19 | Download and run the application:
20 |
21 | ```
22 | curl -L https://github.com/amyboyd/go-mailgun-mailing-list-api/releases/download/v0.2.0/mailgun-mailing-list-api -o mailgun-mailing-list-api
23 | chmod +x mailgun-mailing-list-api
24 | ./mailgun-mailing-list-api
25 | ```
26 |
27 | Add a form to your web page that submits the user's email address to the API:
28 |
29 | ```html
30 |
34 | ```
35 |
36 |
37 | Monitoring
38 | ----------
39 |
40 | If you want to set up monitoring, to check the API is running at all times, the API has a URL for that, `/health-check`
41 |
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/bin/build:
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1 | set -o errexit
2 | set -o nounset
3 |
4 | TARGET=build/mailgun-mailing-list-api
5 |
6 | go build -o $TARGET
7 |
8 | echo "Executable has been created: $TARGET"
9 |
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/main.go:
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1 | package main
2 |
3 | import (
4 | "fmt"
5 | mailgun "github.com/mailgun/mailgun-go"
6 | "log"
7 | "net/http"
8 | "os"
9 | "strconv"
10 | "strings"
11 | "unicode/utf8"
12 | )
13 |
14 | type Config struct {
15 | Domain string
16 | ApiKey string
17 | MailingListAddress string
18 | HttpPort int
19 | RedirectUrlAfterSubscribe string
20 | }
21 |
22 | func main() {
23 | if len(os.Args) > 1 {
24 | command := os.Args[1]
25 | if command == "--help" {
26 | PrintHelp()
27 | } else {
28 | log.Fatal("unknown argument: " + command)
29 | }
30 | } else {
31 | RunApplication()
32 | }
33 | }
34 |
35 | func RunApplication() {
36 | config := CreateConfigFromEnv()
37 |
38 | PrintConfig(config)
39 |
40 | mg := mailgun.NewMailgun(config.Domain, config.ApiKey, "")
41 |
42 | StartHttpServer(mg, config)
43 | }
44 |
45 | func CreateConfigFromEnv() Config {
46 | httpPort, err := strconv.Atoi(GetConfigVarFromEnv("SUBSCRIBE_HTTP_PORT"))
47 |
48 | if err != nil {
49 | log.Fatal("HTTP port must be numeric, given: " + GetConfigVarFromEnv("SUBSCRIBE_HTTP_PORT"))
50 | }
51 |
52 | return Config{
53 | Domain: GetConfigVarFromEnv("MAILGUN_DOMAIN"),
54 | ApiKey: GetConfigVarFromEnv("MAILGUN_API_KEY"),
55 | MailingListAddress: GetConfigVarFromEnv("MAILGUN_MAILING_LIST"),
56 | HttpPort: httpPort,
57 | RedirectUrlAfterSubscribe: GetConfigVarFromEnv("SUBSCRIBE_REDIRECT_URL"),
58 | }
59 | }
60 |
61 | func GetConfigVarFromEnv(envVar string) string {
62 | value := os.Getenv(envVar)
63 |
64 | if value == "" {
65 | log.Fatal("System environment not set: " + envVar)
66 | }
67 |
68 | return value
69 | }
70 |
71 | func PrintConfig(config Config) {
72 | fmt.Println("Running with configuration:")
73 |
74 | fmt.Println("Mailgun domain (from MAILGUN_DOMAIN):", config.Domain)
75 |
76 | // Redact the API key incase the output is redirected to a log file and, for example, sent
77 | // to a Kibana log server, where the users of the log server shouldn't know the private key.
78 | redactedApiKey := config.ApiKey[0:10] + strings.Repeat("*", utf8.RuneCountInString(config.ApiKey)-10)
79 | fmt.Println("Mailgun API key (from MAILGUN_API_KEY):", redactedApiKey)
80 |
81 | fmt.Println("Mailgun mailing list (from MAILGUN_MAILING_LIST):", config.MailingListAddress)
82 |
83 | fmt.Println("HTTP port (from SUBSCRIBE_HTTP_PORT):", config.HttpPort)
84 |
85 | fmt.Println("Redirect URL after subscribe (from SUBSCRIBE_REDIRECT_URL):", config.RedirectUrlAfterSubscribe)
86 | }
87 |
88 | func StartHttpServer(mg mailgun.Mailgun, config Config) {
89 | http.HandleFunc("/subscribe", func(response http.ResponseWriter, request *http.Request) {
90 | email := request.FormValue("email")
91 |
92 | newMember := mailgun.Member{
93 | Address: email,
94 | Subscribed: mailgun.Subscribed,
95 | }
96 |
97 | mg.CreateMember(true, config.MailingListAddress, newMember)
98 |
99 | fmt.Println(email + " has been subscribed to the mailing list")
100 |
101 | http.Redirect(response, request, config.RedirectUrlAfterSubscribe, http.StatusTemporaryRedirect)
102 | })
103 |
104 | http.HandleFunc("/health-check", func(response http.ResponseWriter, request *http.Request) {
105 | fmt.Fprintf(response, "Running")
106 | })
107 |
108 | http.ListenAndServe(":"+strconv.Itoa(config.HttpPort), nil)
109 | }
110 |
111 | func PrintHelp() {
112 | fmt.Println("You can report issues at: https://github.com/amyboyd/go-mailgun-mailing-list-api/issues")
113 | fmt.Println("You can download the latest binary from: https://github.com/amyboyd/go-mailgun-mailing-list-api/releases")
114 | fmt.Println("The source code is available at: https://github.com/amyboyd/go-mailgun-mailing-list-api")
115 | }
116 |
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/sample-env.sh:
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1 | export MAILGUN_DOMAIN=mg.yourdomain.com
2 | export MAILGUN_API_KEY=key-abcdefghijkl
3 | export MAILGUN_MAILING_LIST=newsletter@mg.yourdomain.com
4 | export SUBSCRIBE_HTTP_PORT=8000
5 | export SUBSCRIBE_REDIRECT_URL=http://yourdomain.com/newsletter/success
6 |
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/tests/test.html:
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1 |
5 |
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