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APNs and FCM provider server on HTTP/2.

  • Gunfish provides the nterface as the APNs / FCM provider server.


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Quick Started

$ go get
$ gunfish -c ./config/gunfish.toml -E production

Commandline Options

option required description
-port Optional Port number of Gunfish provider server. Default is 8003.
-environment, -E Optional Default value is production.
-conf, -c Optional Please specify this option if you want to change toml config file path. (default: /etc/gunfish/config.toml.)
-log-level Optional Set the log level as 'warn', 'info', or 'debug'.
-log-format Optional Supports json or ltsv log formats.
-enable-pprof Optional You can set the flag of pprof debug port open.
-output-hook-stdout Optional Merge stdout of hook command to gunfish's stdout.
-output-hook-stderr Optional Merge stderr of hook command to gunfish's stderr.


POST /push/apns

To delivery remote notifications via APNS to user's devices.

param description
Array Array of JSON dictionary includes 'token' and 'payload' properties
payload param description
token Published token from APNS to user's remote device
payload APNS notification payload

Post JSON example:

    "payload": {
      "aps": {
        "alert": "test notification",
        "sound": "default"
      "option1": "foo",
      "option2": "bar"
    "token": "apns device token",
    "header": {
      "apns-id": "your apns id",
      "apns-topic": "your app bundle id",
      "apns-push-type": "alert"

Response example:

{"result": "ok"}

POST /push/fcm

To delivery remote notifications via FCM (legacy) API to user's devices.

Post body format is equal to it for FCM legacy origin server.


  "registration_ids": [
  "data": {
    "id": "2",
    "message": "Test2"
  "notification": {
    "title": "message_title",
    "body": "message_body"

Response example:

{"result": "ok"}

POST /push/fcm/v1

To delivery remote notifications via FCM v1 API to user's devices.

Post body format is equal to it for FCM v1 origin server.


  "message": {
    "notification": {
      "title": "message_title",
      "body": "message_body",
      "image": ""
    "data": {
      "sample_key": "sample key",
      "message": "sample message"
    "token": "InstanceIDTokenForDevice"

Response example:

{"result": "ok"}

FCM v1 endpoint allows multiple payloads in a single request body. You can build request body simply concat multiple JSON payloads. Gunfish sends for each that payloads to FCM server. Limitation: Max count of payloads in a request body is 500.

GET /stats/app

  "pid": 57843,
  "debug_port": 0,
  "uptime": 384,
  "start_at": 1492476864,
  "su_at": 0,
  "period": 309,
  "retry_after": 10,
  "workers": 8,
  "queue_size": 0,
  "retry_queue_size": 0,
  "workers_queue_size": 0,
  "cmdq_queue_size": 0,
  "retry_count": 0,
  "req_count": 0,
  "sent_count": 0,
  "err_count": 0,
  "certificate_not_after": "2027-04-16T00:53:53Z",
  "certificate_expire_until": 315359584

To get the status of APNS proveder server.

stats type description
pid PID
debug_port pprof port number
uptime uptime
workers number of workers
start_at The time of started
queue_size queue size of requests
retry_queue_size queue size for resending notification
workers_queue_size summary of worker's queue size
command_queue_size error hook command queue size
retry_count summary of retry count
request_count request count to gunfish
err_count count of recieving error response
sent_count count of sending notification
certificate_not_after certificates minimum expiration date for APNs
certificate_expire_until certificates minimum expiration untile (sec)

GET /stats/profile

To get the status of go application.

See detail properties that url: (


The Gunfish configuration file is a TOML file that Gunfish server uses to configure itself. That configuration file should be located /etc/gunfish.toml, and is required to start. Here is an example configuration:

port = 8203
worker_num = 8
queue_size = 2000
max_request_size = 1000
max_connections = 2000
error_hook = "echo -e 'Hello Gunfish at error hook!'"

key_file = "/path/to/server.key"
cert_file = "/path/to/server.crt"
kid = "kid"
team_id = "team_id"

api_key = "API key for FCM"

google_application_credentials = "/path/to/credentials.json"
param status description
port optional Listen port number.
worker_num optional Number of Gunfish owns http clients.
queue_size optional Limit number of posted JSON from the developer application.
max_request_size optional Limit size of Posted JSON array.
max_connections optional Max connections
key_file required The key file path.
cert_file optional The cert file path.
kid optional kid for APNs provider authentication token.
team_id optional team id for APNs provider authentication token.
error_hook optional Error hook command. This command runs when Gunfish catches an error response.
api_key optional FCM api key. If you want to delivery notifications to android, it is required.

Error Hook

Error hook command can get an each error response with JSON format by STDIN.

for example JSON structure: (>= v0.2.x)

// APNs
  "provider": "apns",
  "apns-id": "123e4567-e89b-12d3-a456-42665544000",
  "status": 400,
  "token": "9fe817acbcef8173fb134d8a80123cba243c8376af83db8caf310daab1f23003",
  "reason": "MissingTopic"
// FCM
  "provider": "fcm",
  "status": 200,
  "registration_id": "8kMSTcfqrca:APA91bEfS-uC1WV374Mg83Lkn43..",
  // or "to": "8kMSTcfqrca:APA91bEfS-uC1WV374Mg83Lkn43..",
  "error": "InvalidRegistration"
// FCM v1
  "provider": "fcmv1",
  "status": 400,
  "token": "testToken",
  "error": {
    "status": "INVALID_ARGUMENT",
    "message": "The registration token is not a valid FCM registration token"

Graceful Restart

Gunfish supports graceful restarting based on Start Server. So, you should start on start_server command if you want graceful to restart.

### install start_server
$ go get

### Starts Gunfish with start_server
$ start_server --port 38003 --pid-file -- ./gunfish -c conf/gunfish.toml


How to Implement Response Handlers

If you have to handle something on error or on success, you should implement error or success handlers. For example handlers you should implement is given below:

type CustomYourErrorHandler struct {
    hookCmd string

func (ch CustomYourErrorHandler) OnResponse(result Result){
    // ...

func (ch CustomYourErrorHandler) HookCmd( ) string {
    return ch.hookCmd

Then you can use these handlers to set before to start gunfish server ( gunfish.StartServer( Config, Environment ) ).

InitErrorResponseHandler(CustomYourErrorHandler{hookCmd: "echo 'on error!'"})

You can implement a success custom handler in the same way but a hook command is not executed in the success handler in order not to make cpu resource too tight.


Requires dep for vendoring.

$ make test

The following tools are useful to send requests to gunfish for test the following.

  • gunfish-cli (send push notification to Gunfish for test)
  • apnsmock (APNs mock server)
$ make tools/gunfish-cli
$ make tools/apnsmock
  • send a request example with gunfish-cli

    $ ./gunfish-cli -type apns -count 1 -json-file some.json -verbose
    $ ./gunfish-cli -type apns -count 1 -token <device token> -apns-topic <your topic> -options key1=val1,key2=val2 -verbose
  • start apnsmock server

    $ ./apnsmock -cert-file ./test/server.crt -key-file ./test/server.key -verbose


Gunfish repository includes Lua script for the benchmark. You can use wrk command with err_and_success.lua script.

$ make tools/apnsmock
$ ./apnsmock -cert-file ./test/server.crt -key-file ./test/server.key -verbosea &
$ ./gunfish -c test/gunfish_test.toml -E test
$ wrk2 -t2 -c20 -s bench/scripts/err_and_success.lua -L -R100 http://localhost:38103


Gunfish Info

⭐ Stars 34
🔗 Source Code
🕒 Last Update 2 years ago
🕒 Created 6 years ago
🐞 Open Issues 6
➗ Star-Issue Ratio 6
😎 Author kayac