node.js, domino-db & Docker (13): Logging gRPC requests

For logging the gRPC requests you can use nginx as a reverse proxy. gRPC support was added in version 1.13.10.

To install it locally on your Domino server (RHEL), open a terminal and do the following:

1. Identify which version you are running

cat /etc/redhat-release

The resulting output tells you which major version you are using:

[notes@redhat-dev-hq /]$ cat /etc/redhat-release 
Red Hat Enterprise Linux Server release 7.6 (Maipo)

2. Add the nginx repository

sudo vi /etc/yum.repos.d/nginx.repo

3. Add the repo data

[nginx]
name=nginx repo
baseurl=http://nginx.org/packages/rhel/7/$basearch/
gpgcheck=0
enabled=1

The „7“ in the base url is the major version from step 1.

4. Install nginx

sudo yum install nginx

5. Create a new config for gRPC

sudo vi /etc/nginx/conf.d/grpc.conf

6. Add the debug log configuration

server {
     listen 81 http2;

     access_log /var/log/nginx/grpc-access.log main;
     error_log /var/log/nginx/grpc-debug.log debug;

     location / {
        grpc_pass grpc://localhost:3002;
     }
}

The reverse proxy is now listening on port 81. You have to change the port in the application configuration. The „error_log“ is our debug log, the „access_log“ logs just the requests itself.

If you are new to vim: First you have to press „i“ to insert text. After pasting the configuration above, press <ESC>, then :w<ENTER>, then :q<ENTER>

7. Test the configuration

[notes@redhat-dev-hq /]$ sudo nginx -t
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
nginx: configuration file /etc/nginx/nginx.conf test is successful

8. Start the nginx debug task & enjoy the results

sudo service nginx stop
sudo service nginx-debug start

Now the log file is full with the complete debug information about the incoming gRPC request.