Introduction

In the IBM Cloud, there is a base management network. If you don’t know, there isn’t an obvious way to access it from your laptop. After some headbanging I’ve figured out how to bridge my management network and my workload network with a nginx reverse proxy to allow me to run commands from working network to interface with vCenter.

tl;dr: I want to run terraform from my laptop to my vCenter, I can’t VPN into my 10.x but I can VPN into my 172.x network. Using a machine that bridges with nginx I can now talk to my vCenter through my proxied machine.

Setup

I’ll go ahead and use my real IPs here so we don’t get lost with fake numbers, luckily these are all behind a firewall that is nowhere near the internet, so knowing these you shouldn’t be able to use these other than an example. Ok, here we go:

First thing, I had to create a machine that had two NICs, working on the internal management network, and my internal VPN network. My management network was named: asgharlabs-asghar-dpg-mgmt with the IP range of: 10.220.145.x . My VPN/workload network was named: vxw-dvs-40-virtualwire-3-sid-6002-Workload with the IP range of: 172.16.10.x . I added a static IP to the management network, but let DHCP take care of my workload network. Awesome, I have a machine that can now ping both sides and reach both locations I’m trying to get to.

Next, I do the obvious, I install nginx, I’m using CentOS, so I did it via the following command:

sudo yum install nginx

Then I enable and start the process:

sudo systemctl enable nginx sudo systemctl start nginx

I verified that I saw the “Welcome to Nginx” page, to verify that everything was setup as expect.

Next, I made sure my firewalld was set up correctly:

sudo firewall-cmd --permanent --zone = public --add-service = http sudo firewall-cmd --permanent --zone = public --add-service = https sudo firewall-cmd --reload

And finally, (Major please don’t yell at me) I disabled SELinux. I converted it from enforcing to disabled and reboot my machine. Now, let’s configure the meat of this blog post.

Nginx reverse proxy set up

So if you’ve Google’d around looking for a way to do this, you probably have come across this repository, 5 years ago this was really the only reference for this action. I took from his work and updated for the VCSA 6.7+ that I’m running. Luckily everything goes over https now and standard ports, so it actually makes the vcsa.conf hella, easier.

Take the following configuration file, drop it in a logical place, such as /etc/nginx/conf.d/vcsa.conf and change out the IPs, that is commented on in it.

proxy_set_header Host $ http_host ; proxy_set_header X - Real - IP $ remote_addr ; proxy_set_header X - Forwared - For $ proxy_add_x_forwarded_for ; # # The upstream VCSA hostname or IP address for port 443 # upstream vcsa - 443 { server 10 . 220 . 145 . x : 443 ; } # # HTTP => HTTPS redirect # server { listen 80 ; server_name 172 . 16 . 10 . x ; # Your local machine location / { allow all ; return 302 https ://$ server_name $ request_uri ; } } # # Main HTTPS Reverse Proxy for the VCSA # server { listen 443 ssl ; server_name 172 . 16 . 10 . 217 ; ssl_certificate / etc / ssl / certs / nginx - selfsigned . crt ; # you'll need your selfsigned cert here ssl_certificate_key / etc / ssl / private / nginx - selfsigned . key ; # you'll need your selfsigned key here ssl_protocols TLSv1 TLSv1 . 1 TLSv1 . 2 ; ssl_ciphers HIGH :! aNULL :! MD5 ; keepalive_timeout 60 ; location / { allow all ; proxy_set_header Host $ http_host ; proxy_pass https :// vcsa - 443 ; proxy_ssl_server_name on ; } }

Lastly, you’ll need to set up some self-signed certs, I found the easiest way was here, it walks you through everything, and as you can see drops your certs in /etc/ssl/certs which is coded in the above configuration file.

Finally, restart nginx via something like service nginx restart and you should be good to go.

Oh! A final gotcha, you may have to add to your DNS or (like in my case) to my /etc/hosts file the full VCSA hostname to the proxied VM, ( x is the IP ;) ). For instance:

172.16.10.x asgharlabs-vc.asgharlabs.io

After figuring out the incantation, it seems pretty straight forward, and hope this helps someone in the future.