ngrok

Intro

The plan is to create a pair of executables (ngrok and ngrokd) that are connected with a self-signed SSL cert. Since the client and server executables are paired, you won’t be able to use any other ngrok to connect to this ngrokd, and vice versa.

DNS

Add two DNS records: one for the base domain and one for the wildcard domain. For example, if your base domain is domain.com, you’ll need a record for that and for *.domain.com.

Different Operating Systems

If the OS on which you’ll be compiling ngrok (that’s the server section below) is different than the OS on which you’ll be running the client, then you will need to set the GOOS and GOARCH env variables. I run Linux everywhere, so I don’t know how to do that. Please Google it or see the discussion here. If you know how to do this and want to add GOOS/GOARCH instructions here, please let me know.

On Server

MAKE SURE YOU SET NGROK_DOMAIN BELOW. Set it to the base domain, not the wildcard domain.

NGROK_DOMAIN="my.domain.com"
git clone https://github.com/inconshreveable/ngrok.git
cd ngrok

openssl genrsa -out rootCA.key 2048
openssl req -x509 -new -nodes -key rootCA.key -subj "/CN=$NGROK_DOMAIN" -days 5000 -out rootCA.pem
openssl genrsa -out device.key 2048
openssl req -new -key device.key -subj "/CN=$NGROK_DOMAIN" -out device.csr
openssl x509 -req -in device.csr -CA rootCA.pem -CAkey rootCA.key -CAcreateserial -out device.crt -days 5000

cp rootCA.pem assets/client/tls/ngrokroot.crt
# make clean
make release-server release-client

Copy bin/ngrok to whatever computer you want to connect from. Then start the server:

bin/ngrokd -tlsKey=device.key -tlsCrt=device.crt -domain="$NGROK_DOMAIN" -httpAddr=":8000" -httpsAddr=":8001"

On Client

MAKE SURE YOU SET NGROK_DOMAIN BELOW. Set it to the base domain, not the wildcard domain.

NGROK_DOMAIN="my.domain.com"
echo -e "server_addr: $NGROK_DOMAIN:4443\ntrust_host_root_certs: false" > ngrok-config
./ngrok -config=ngrok-config 80

Or for SSH forwarding: ./ngrok -config=ngrok-config –proto=tcp 22

Define a fixed TCP listen port

Set port number to the remote_port args. Be sure to pay attention to the format

tunnels:
  mysql:
    proto:
      tcp:3306
    remote_port: 36799

Run ngrok client with -config

Create an ngrok configuration file, “debug.yml” with the following contents:

server_addr: ngrok.domain.com:4443
trust_host_root_certs: false
tunnels:
  ssh:
    proto:
      http: 22
    subdomain: 22
  mysql:
    proto:
      tcp: 3306
    remote_port: 36799

Then run ngrok

./bin/ngrok -config=debug.yml -log=stdout start-all