[5 Mins Docker] Deploy Nexterm (an open-source server management software) to Manage Your Servers into Cloud Platforms

This post introduces Nexterm software which is an open-source server management software designed for handling SSH, VNC, and RDP connections. It actually uses guacd under the hood for both RDP and VNC, which comes bundled within the docker image. It provides a unified platform to manage remote connections securely and efficiently. This guide details how to deploy Nexterm using Docker.

 Other related posts:

• Using Portainer to Deploy Guacamole As Web Based Remote Access Gateway (Updated) & KASM Installation
• Using Portainer and Docker to Deploy Guacamole Clientless Remote Desktop Gateway
• Deployment of KASM with Four Commands or Using Docker to Deploy
• Next Terminal - Another Interactive Auditing Bastion System (Simple to Install and Easy to Use)
• Fast Deploy Two Open Source Bastion Server Projects - Webterminal and Jumpserver
• [5 Min Docker] Free Sshwifty Web SSH & Telnet Client Deploy to Cloud Platforms (Koyeb, Render)

Nexterm Project Highlights

Here are some words from https://github.com/gnmyt/Nexterm

Nexterm is an open-source server management software that allows you to:

• Connect remotely via SSH, VNC and RDP
• Manage files through SFTP
• Deploy applications via Docker
• Manage Proxmox LXC and QEMU containers
• Secure access with two-factor authentication

Screenshot:

Docker Deployment Steps

Based on doc installation web page: https://docs.nexterm.dev/preview, here are deployment steps.

1 log into linux vps

• sudo -i
• apt update 

2 (optional) increase swap size if needed

• SWAP size increase: wget https://raw.githubusercontent.com/51sec/swap/main/swap.sh && bash swap.sh

3 install docker & docker compose

• apt install docker.io
• apt install docker-compose
• (optional) apt upgrade docker.io

4 Create docker data structure

• mkdir /root/data/docker_data/nexterm
• cd /root/data/docker_data/nexterm

5 run Calibre-web docker

Root User to Run Docker

• vi docker-compose.yml

services:
  nexterm:
    environment:
      ENCRYPTION_KEY: "aba3aa8e29b9904d5d8d705230b664c053415c54be20ad13be99af0057dfa23a" # Replace with your generated key
    ports:
      - "6989:6989"
    restart: always
    volumes:
      - nexterm:/app/data
    image: germannewsmaker/nexterm:1.0.3-OPEN-PREVIEW
volumes:
  nexterm:

Notes:Explanation of Key Components¶

• Image: Specifies the Docker image germannewsmaker/nexterm:1.0.1-OPEN-PREVIEW, which is the preview version of Nexterm.
• Ports: Maps port 6989 on the host to port 6989 inside the container, allowing access to Nexterm via http://<your-server-ip>:6989.
• Volumes: A named volume nexterm:/app/data is used to persist data. This volume ensures that configuration and data are retained across container restarts. Data in Docker containers is lost when the container is removed unless it's saved in a volume. This setup keeps your data safe.

• nexterm — This is the name of the Docker volume on the host machine. If we are using /nexterm in -v parameter, such as -v /nexterm:/app/data, that will mean nexterm is a folder on the host. 

• /app/data — This is the path inside the container where the volume will be mounted.

• Restart: Configured to always so the container will automatically restart in case of failures.

docker-compose up -d

Docker run command:

docker run -d \
  -e ENCRYPTION_KEY="aba3aa8e29b9904d5d8d705230b664c053415c54be20ad13be99af0057dfa23a" \
  -p 6989:6989 \
  --name nexterm \
  --restart always \
  -v nexterm:/app/data \
  germannewsmaker/nexterm:1.0.3-OPEN-PREVIEW

Update 

cp -r /root/data/docker_data/nexterm /root/data/docker_data/nexterm.archive  # backup first
cd /root/data/docker_data/nexterm  # cd into docker-compose folder
docker-compose pull    # pull latest image
docker-compose up -d   # bring up the docker

Uninstall

cd /root/data/docker_data/nexterm  # Enter docker-compose folder
docker-compose down    # bring down the docker
rm -rf /root/data/docker_data/nexterm  # delete all data mapped to local host folders

Deployment at Render

https://dashboard.render.com/

Free Web Service in Hobby Plan: 512MB RAM and 0.1CPU.  100GB Free Bandwidth, 500 Minutes Free Pipeline/Month, Free PostgreSQL, Docker Builds, Up to 2 Custom Domains with Free TLS. 

No persistant storage/volumns.  

- from : https://render.com/pricing

Assume you have an account created already. Here are steps with screenshot to create this nexterm service in Render.com. 

1 After created your project, you can create a new web service using +Add new button.

2 Select Existing Image then enter image url:

germannewsmaker/nexterm:1.0.3-OPEN-PREVIEW

Click Connect to next step.

3 Select Free Instance Type for your new Nexterm web service.

4 At the same page, add a new Environment Variable

ENCRYPTION_KEY

You can use openssl rand -hex 32 to generate your own key to add in. 

Click Deploy

5 Deployed the web service

Unfortunately, there is no persistent data volume in Free plan. Once system got suspended because of inactive, all your conifguration will lost including the account you created. 

First time to use, it will ask you to register an account:

After log in, you can create session folders, then add your servers in. 

You also can create a new account, enable 2fa,

Fly.io

 

https://fly.io/docs/getting-started/

https://fly.io/docs/hands-on/

https://fly.io/docs/about/pricing/#legacy-free-allowances

Legacy Free allowances

The following resources were included for free on the Hobby (deprecated), Launch, and Scale plans, and are still honored for any organizations that were on these plans before we sunset them:

• Up to 3 shared-cpu-1x 256mb VMsY
• 3GB persistent volume storage (total)

Outbound data transfer:

• 100 GB North America & Europe
• 30 GB Asia Pacific, Oceania & South America
• 30 GB Africa & India

1 Install flyctl if you are using Windows machine. For other OS, check installation guide:

powershell -Command "iwr https://fly.io/install.ps1 -useb | iex"

2 Close CMD or Powershell  terminal and open a new one to continue next command:

fly launch

• Follow the instructions to install fly's command-line interface flyctl.
• log into flyctl.

3 flyctl auth login

4 flyctl launch

This command creates a fly.toml file.

5 Edit your fly.toml (notepad fly.tomlfly.)

# fly.toml file generated for memos

app = "nexterm"                                               # change to whatever name you want if the name is not occupied
kill_signal = "SIGINT"
kill_timeout = 5
processes = []

[build]
  image = "germannewsmaker/nexterm:1.0.3-OPEN-PREVIEW"                                # Do not change unless you build your own image

[env]
  ENCRYPTION_KEY = "aba3aa8e29b9904d5d8d705230b664c053415c54be20ad13be99af0057dfa23a"

[mounts]
  source="nexterm_data"                                               # change to your fly.io volume name
  destination="/app/data"                                      # do not change

[[services]]
  http_checks = []
  internal_port = 6989                                             # change to port 6989
  processes = ["app"]
  protocol = "tcp"
  script_checks = []
  [services.concurrency]
    hard_limit = 25
    soft_limit = 20
    type = "connections"

  [[services.ports]]
    force_https = true
    handlers = ["http"]
    port = 80

  [[services.ports]]
    handlers = ["tls", "http"]
    port = 443

  [[services.tcp_checks]]
    grace_period = "1s"
    interval = "15s"
    restart_limit = 0
    timeout = "2s"

Create Volume:

flyctl volumes create nexterm_data --region <your_region> --size <size_in_gb>

For example:

flyctl volumes create nexterm_data --region yyz --size 1

6 flyctl deploy

7 Other Fly.io commands

fly orgs list
fly apps list
fly volumes list -a memos

run.claw.cloud

$5 / Month free credit.  

Application name : nexterm

not Nexterm

Enable public access and put 6989 as container port

Add encryption key as an environment variable

add 1GB as local storage. Maximum is 20GB.

Deploy application.

Total cost will be $0.05/day , and you have a $5 free credit / month. So it will be good for 100 days, which means you can get scale up your instance here. 

Custom domain might not work based on my testing. Other than this error for custom domain, all works great. 

CodeSandbox - TBC

Still working on it. To be continued.

https://codesandbox.io/

Plan: Free 

• 400 VM credits started, Up to 57.1 hours worth of VM credits per month (minimum 7 credit / hour for 1vCPU, 2G RAM, 20GB Disk)
• 5 sandboxes

+Create

Explore Template and Choose Docker

Select Pico VM Specs （1 vCPU, 2G RAM, 20G Disk for 7 credits/hour）=57.1 hours

Run Docker command wont work from a new Terminal Console:

Outputs:

➜  workspace git:(main) docker run -d \
  -e ENCRYPTION_KEY="aba3aa8e29b9904d5d8d705230b664c053415c54be20ad13be99af0057dfa23a" \
  -p 6989:6989 \
  --name nexterm \
  --restart always \
  -v nexterm:/app/data \
  germannewsmaker/nexterm:1.0.3-OPEN-PREVIEW
Unable to find image 'germannewsmaker/nexterm:1.0.3-OPEN-PREVIEW' locally
1.0.3-OPEN-PREVIEW: Pulling from germannewsmaker/nexterm
f18232174bc9: Pull complete 
cb2bde55f71f: Pull complete 
9d0e0719fbe0: Pull complete 
6f063dbd7a5d: Pull complete 
cf1d045960c7: Pull complete 
4e365c3723a1: Pull complete 
206100c2fa94: Pull complete 
cfbc3eac6fe8: Pull complete 
5e25bbebb873: Pull complete 
c0d150f0745c: Pull complete 
ca63da039d11: Pull complete 
a1d52f0b7c3e: Pull complete 
96849131fbda: Pull complete 
765f2a89adb7: Pull complete 
Digest: sha256:1a8282db701a9babdb78794872b5cc06f117ff3e7f1704cdabf7ab89df2906c2
Status: Downloaded newer image for germannewsmaker/nexterm:1.0.3-OPEN-PREVIEW
aa6ae06ae80e76c9f5e71f545e53064d41fd59f97de594074eadbd46ed76b7bb
docker: Error response from daemon: failed to set up container networking: driver failed programming external connectivity on endpoint nexterm (7312389909dfab6e5d328235099590c9fb2c3b289205ee460462dc12cb92b264): Unable to enable LOOPBACK FILTERING - DROP rule:  (iptables failed: iptables --wait -t raw -A PREROUTING -p tcp -d 127.0.0.1 --dport 6989 ! -i lo -j DROP: iptables v1.8.10 (legacy): can't initialize iptables table `raw': Table does not exist (do you need to insmod?)
Perhaps iptables or your kernel needs to be upgraded.
 (exit status 3)).
➜  workspace git:(main) 

https://blog.51sec.org/2024/11/use-cloudflared-docker-to-map-your-sub.html

3 Modify tasks.json file under workspace/.codesandbox

4 Create docker-compose.yaml file under workspace / .devcontainer

5 Once you pressed ctrl+s to save docker-compose.yaml file, it will ask you to rebuild & restart the deccontainers.

TBC.

Videos

 

References

• https://github.com/DmitryScaletta/free-heroku-alternatives
• https://blog.laoda.de/archives/docker-compose-install-nexterm
• https://github.com/gnmyt/Nexterm
• https://docs.nexterm.dev/preview
• How to Install Nexterm on Your Synology NAS