How to run ngrok in background?

Question

I tried running ngrok in the background with following command:

./ngrok -subdomain test -config=ngrok.cfg 80 &

the process is running:

[1] 3866

and the subdomain doesn't work.

It works with:

./ngrok -subdomain test -config=ngrok.cfg 80

Does anyone know what is going wrong here?

Thank you.

score 42 · Answer 1 · answered Feb 17 '18 at 13:39

42

as described previously you can run ngrok in background with

./ngrok http 8080 > /dev/null &

next you can use curl and for example jq a command-line JSON processor.

export WEBHOOK_URL="$(curl http://localhost:4040/api/tunnels | jq ".tunnels[0].public_url")"

your URL will be accessible from $WEBHOOK_URL env variable and you can use it anywhere.

answered Feb 17 '18 at 13:39

Artem Zinoviev

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This is by far the best solution for programatically accessing it! – the1dv Apr 26 '18 at 01:55
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did you check it? – Tebe Jan 19 '19 at 16:56
5

I might suggest `curl --silent` (or `curl -s`) and `jq -r` to have quieter output. So: `$(curl -s http://localhost:4040/api/tunnels | jq -r '.tunnels[0].public_url')` inside the double quotes. (Feel free to pull this into the answer; leaving it as a comment for now.) – lindes May 21 '19 at 06:18
This is not deterministic if you have more than one tunnel. A simple workaround is to force just one tunnel by using only HTTPS: `ngrok http --bind-tls=true --log=stdout 8080 > /dev/null &` – Juliusz Gonera Feb 18 '20 at 00:42
`jq: error: Could not open file .tunnels[0].public_url: No such file or directory` – alper May 19 '21 at 21:52

score 40 · Accepted Answer · answered Nov 27 '14 at 05:33

40

as explained here

ngrok -log=stdout 80 > /dev/null &

answered Nov 27 '14 at 05:33

martinenzinger

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Does not work for ngrok2. Any ideas for the new version? – IvanD Jan 13 '16 at 07:09
@toas939 Oh, thanks man! Too much answers, and none of them is correct. – Kirby Apr 12 '18 at 13:52
If you want to run this in a production environment and without having to open up your terminal, you can create and run ngrok as a service that will automatically start when your machine boots. Check here for instructions. https://ngrok.com/docs/ngrok-link#service – dave4jr Oct 06 '18 at 00:30
@dave4jr: Is ngrok-link included in the ngrok client or does one have to install something else? The service command isn't recognized by ngrok – AndyFaizan Nov 15 '18 at 14:59
1

@AndyFaizan Unfortunately it does cost a little extra, I forget how much our company paid for this but I don't remember it being a lot. – dave4jr Nov 22 '18 at 06:14
Okay. I asked because I already have a paid account but it still didn't work. Well, thanks anyway. – AndyFaizan Nov 22 '18 at 12:30
I want to ngrok a folder into the background... how can I do this? `./ngrok http file:///my-folder -log=stdout http > /dev/null &` doesn't work :( – Ryan H Oct 21 '20 at 19:05
How can I get obtain its output? – alper May 19 '21 at 21:46
As of version 2.0.24, ngrok http 80 --log=stdout > ngrok.log & did the trick. – rlib Jul 22 '21 at 13:49

score 19 · Answer 3 · answered Jan 15 '20 at 17:02

19

Easy: ngrok http 80 --log=stdout > ngrok.log & did the trick.

answered Jan 15 '20 at 17:02

Kyrylo Malakhov

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`nohup ngrok http 80 --log=stdout > ngrok.log &` seems like safer in case ssh connection is dead – alper May 19 '21 at 21:50

score 15 · Answer 4 · edited May 23 '17 at 12:32

15

Visit http://localhost:4040/status on your local machine, or see more here: View random ngrok URL when run in background.

edited May 23 '17 at 12:32

Community

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answered Nov 14 '16 at 07:33

Oliv

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Or sign up for a free account on the ngrok site and connect your local install to it - then you can view your active tunnels online. – Tim Malone Jun 27 '17 at 22:38

bobmarksie · Answer 5 · 2019-08-28T08:46:28.200

Here's a little bash script I wrote which runs ngrok in the background. It then tries to sets a NGROK_PUBLIC_URL variable by calling a curl command (against http://127.0.0.1:4040/api/tunnels) followed by a sed command (which extracts the ngrok public URL). This all runs inside a loop until NGROK_PUBLIC_URL has a valid value as it normally takes ngrok 2 or 3 seconds for it's tunnels to become established.

`start-ngrok.sh`

#!/bin/sh

# Set local port from command line arg or default to 8080
LOCAL_PORT=${1-8080}

echo "Start ngrok in background on port [ $LOCAL_PORT ]"
nohup ngrok http ${LOCAL_PORT} &>/dev/null &

echo -n "Extracting ngrok public url ."
NGROK_PUBLIC_URL=""
while [ -z "$NGROK_PUBLIC_URL" ]; do
  # Run 'curl' against ngrok API and extract public (using 'sed' command)
  export NGROK_PUBLIC_URL=$(curl --silent --max-time 10 --connect-timeout 5 \
                            --show-error http://127.0.0.1:4040/api/tunnels | \
                            sed -nE 's/.*public_url":"https:..([^"]*).*/\1/p')
  sleep 1
  echo -n "."
done

echo
echo "NGROK_PUBLIC_URL => [ $NGROK_PUBLIC_URL ]"

The script takes a port as an optional command line argument i.e.

$ . start-ngrok.sh 1234

Run NGROK in background on port [ 1234 ]
Extracting ngrok public url ...
NGROK_PUBLIC_URL => [ 75d5faad.ngrok.io ]

... but will run on port 8080 if the port isn't supplied ...

$ . start-ngrok.sh 

Run NGROK in background on port [ 8080 ]
Extracting ngrok public url ...
NGROK_PUBLIC_URL => [ 07e7a373.ngrok.io ]

The NGROK_PUBLIC_URL now contains the public url i.e.

$ echo $NGROK_PUBLIC_URL
07e7a373.ngrok.io

This can be accessed / used in your applications.

Note: This script needs to be sourced (. start-ngrok.sh OR source start-ngrok.sh). This is because it is setting an environment variable which wont be available if run normally in a new shell (i.e. ./start-ngrok.sh). See https://superuser.com/q/176783 for more info.

You can also create a little script using pkill / kill etc to stop the background ngrok process: -

`stop-ngrok.sh`

#!/bin/sh

echo "Stopping background ngrok process"
kill -9 $(ps -ef | grep 'ngrok' | grep -v 'grep' | awk '{print $2}')
echo "ngrok stopped"

but this still does not run in the background. It kills when i close the terminal — Poonam, May 03 '20 at 19:35
It doesn't on mine - that's what the `nohup` (no hangup) command does - `nohup ngrok http ${LOCAL_PORT} &>/dev/null &` - see https://en.wikipedia.org/wiki/Nohup for more details. — bobmarksie, May 05 '20 at 06:55
To kill the proces you could have issued a simple: `kill -9 "$(pgrep ngrok)"` — Bogdan Stoica, Jun 03 '20 at 08:43

score 11 · Answer 6 · answered Jan 21 '16 at 23:37

11

In Ngrok 2, -log is neither necessary nor available (though you can control log levels in the configuration file). ngrok > /dev/null & is sufficient.

answered Jan 21 '16 at 23:37

Chandler Swift

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But how do I know the URL to access my service? – Oliv Nov 08 '16 at 17:13
If you want to do that, you'll have to run it in the foreground (AFAIK). Background running is primarily helpful for running as a service, when you'd more than likely know your domain. – Chandler Swift Nov 09 '16 at 00:29
3

See my answer, there is a way. – Oliv Nov 14 '16 at 07:33
Also Artem's answer, https://stackoverflow.com/a/48841928/313756 (with a comment from me to slightly modify it.) – lindes May 21 '19 at 06:53
@Oliv: The easiest way of checking the URL is to log in into the Ngrok web page and using the Dashboard. – Chupo_cro Mar 29 '21 at 13:52

Liudas Šumskas · Answer 7 · 2017-06-14T11:45:40.667

If you want to use multiple shell windows or run any service in the background from a single SSH session that the simplest way is to use screen.

To install on the Centos Linux use yum install screen

Then start like any other command screen, after that type ngrok command within a parameters.

Detaching is the most powerful part of screen. Screen allows you to detach from a window and reattach later.

If your network connection fails, screen will automatically detach your session! You can detach from the window using “Ctrl-a” “D”.

This will drop you back into your shell.

All screen windows are still there and you can re-attach to them later using screen -r

It is generally considered a bad answer if you can't use your answer without the link. — martijnn2008, Jun 14 '17 at 10:03

score 7 · Answer 8 · answered Dec 27 '18 at 09:17

7

curl http://127.0.0.1:4040/api/tunnels

and you will see the public_url infomation .

Here's example . https://i.stack.imgur.com/V0905.png

answered Dec 27 '18 at 09:17

Tung Tran

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score 6 · Answer 9 · answered Sep 27 '17 at 02:43

6

Run ./ngrok http 5000 > /dev/null & then curl localhost:4040/status to check url

answered Sep 27 '17 at 02:43

Old Panda

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need correction , nohup ./ngrok http 5000 > /dev/null & so when we close terminal. process will not get kill – Aakash Kag Jan 12 '18 at 12:28
but this still does not run in the background – Poonam May 03 '20 at 19:34
@Poonam Sorry I didn't put it in my answer. But please check out the `nohup` suggestion as the above comment says. – Old Panda May 03 '20 at 21:54

Hemanth Kondapalli · Answer 10 · 2018-03-27T17:29:46.080

6

Run ./ngrok http (port number) & This runs the ngrok tunnel as a background process. Ngrok usually opens a windown showing the assigned URL but since we are using the nohup command this is not visible.

Thus, then run curl http://127.0.0.1:4040/api/tunnels too see the URL assigned by ngrok

edited Mar 27 '18 at 17:29

answered Jan 22 '18 at 21:12

Hemanth Kondapalli

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updated before, but no longer works. Failed to connect to localhost port 4040: Connection refused. see https://stackoverflow.com/a/48841928/5766054 answer – Stanislau Buzunko Jul 02 '19 at 17:47
but this still does not run in the background. It kills when i close the terminal – Poonam May 03 '20 at 19:35

score 5 · Answer 11 · answered Apr 16 '18 at 22:03

try to run as service. and check it from ngrok website. I tried for ngrok version 2.2.8 on a Raspberry pi 3.

ngrok.service as

[Unit]
Description=Share local port(s) with ngrok
After=syslog.target network.target

[Service]
Type=simple
Restart=always
RestartSec=1min
StandardOutput=null
StandardError=null
ExecStart=/usr/local/sbin/ngrok start --log /var/log/ngrok.log --config /etc/ngrok.yml --all
ExecStop=/usr/bin/killall ngrok

[Install]
WantedBy=multi-user.target

configuration file: ngrok.yml authtoken:

tunnels:
  <your Tunel Name >:
    proto: http
    addr: 80

Poonam · Answer 12 · 2020-05-12T10:25:46.650

5

so i tried everything but the best answer to this which works in the year 2020 is:

how to create public local host(8080):

ngrok -log=stdout 80 > ngrok.log &

then

curl http://127.0.0.1:4040/api/tunnels

edited May 12 '20 at 10:25

answered May 03 '20 at 22:16

Poonam

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Can confirm, best answer for 2020. – Youri Nov 03 '20 at 09:06
doesn't work with ngrok==2.3.35 `Incorrect Usage: flag provided but not defined: -log` – stason Mar 04 '21 at 22:59
1

use `ngrok --log=stdout 80 > ngrok.log &` instead – joifsi May 05 '22 at 07:44

score 4 · Answer 13 · answered Feb 09 '17 at 09:19

4

Use below script for ngrok2

nohup ngrok http 3000 &

This will write logs to file nohup.out

answered Feb 09 '17 at 09:19

Chirag Shah

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nohup.out will not then contain sufficient information to know the API tunnel in use. See Hemanth's response. – Blake Feb 08 '18 at 00:42

score 2 · Answer 14 · answered Jun 17 '19 at 15:51

2

nohup ./ngrok http 80 &

Hit localhost:4040 to get the public URL assigned by ngrok

answered Jun 17 '19 at 15:51

Sagar Gupta

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score 1 · Answer 15 · answered May 15 '18 at 23:07

1

You can use screen for that. Here is an example of how I use it:

screen -d -m ~/./ngrok http test.cc:8080

answered May 15 '18 at 23:07

Beto Aveiga

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score 0 · Answer 16 · answered Jan 04 '19 at 00:01

0

nohup /usr/local/bin/ngrok --config /etc/ngrok.yml http 8080 &

If you link with ngrok account, then you can view the public url in ngrok site, do not need to curl the local url Public url https://dashboard.ngrok.com/status

answered Jan 04 '19 at 00:01

Quang Nguyen

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score 0 · Answer 17 · answered May 09 '20 at 16:26

0

You can use cotunnel. It is ngrok alternative. The cotunnel installation script creates service and works itself on the background.

answered May 09 '20 at 16:26

400ZP

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I think is kinda too much to say it's an alternative... It tries to be but it's way too far away from ngrok as in the flexibility. Plus, honestly, I don't like the ideea that someone is able to ssh into my server without any user/pass directly from their site. From a security perspective, this sucks big time! Installed, checked, uninstalled. Period! – Bogdan Stoica Jun 03 '20 at 07:59

score 0 · Answer 18 · answered Jul 13 '20 at 18:05

Another alternative is using the ngrok npm module. If you have Node installed, you can run ngrok and print out the URL as shown below:

require('ngrok').connect({ proto: 'http', port: 3000 }).then(url => {
  console.log(url);
});

Not strictly running it in the background, but I find this to be the easiest approach for my requirements: starting ngrok and a web server that's aware of its ngrok url in a single command.

score 0 · Answer 19 · answered Mar 06 '21 at 14:18

0

./ngrok http 80 -log=stdout > /dev/null &

answered Mar 06 '21 at 14:18

Abhinivesh Vijayan

1

Please add some explanation to your answer such that others can learn from it - to me, this looks like a duplicate of the existing answers – Nico Haase Mar 08 '21 at 15:28

score 0 · Answer 20 · answered Jul 15 '21 at 05:25

0

In Windows Batch Script (.bat), if you want to execute next command without waiting ngrok, use the following command with start /b:

start /b ngrok http 80 --log=stdout > ngrok.log &

answered Jul 15 '21 at 05:25

Jerry Chong

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Ro. · Answer 21 · 2021-10-26T16:37:24.880

Two steps:

First set console_ui to false in your config file (.ngrok2/ngrok.yml)
Run command like this
```
$ ./ngrok start demo &
```

Extra: if you started this via ssh and you want it to continue running even if you disconnect run it like this

nohup ./ngrok start demo &

Example of my config file

    authtoken: XXXXX
    region: us
    console_ui: false
    web_addr: localhost:4040


    tunnels:    
      demo:
        proto: http
        addr: 9090
        hostname: demo.mysite.com
        inspect: false
        auth: "demo:secret"

score 0 · Answer 22 · edited Aug 25 '23 at 10:13

0

Ngrok now has its own solution for it, which is "installing as a service."

This will start the service on machine boot and restart the service automatically in case of any failure. There is an official document that explains it precisely: https://ngrok.com/docs/secure-tunnels/ngrok-agent/installing-as-a-service/

edited Aug 25 '23 at 10:13

starball

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answered Aug 25 '23 at 10:02

JiboOne

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How to run ngrok in background?

22 Answers22

start-ngrok.sh

stop-ngrok.sh

`start-ngrok.sh`

`stop-ngrok.sh`