VPS Deployment Guide

Obaki VPS Deployment Guide

This guide sets up automated deployment for a .NET API named Obaki running on an Ubuntu VPS.

Target setup:

GitHub Actions
  -> build/test .NET API
  -> dotnet publish
  -> upload published files to VPS
  -> switch /opt/obaki/current symlink
  -> restart obaki systemd service
  -> Caddy reverse proxies traffic to the API

Recommended stack:

Ubuntu VPS
Caddy
systemd
.NET Runtime
GitHub Actions
SSH
rsync

This is lighter than Docker and fits better on a small VPS such as:

1 vCPU
1 GB RAM
25 GB disk

---

1. Install .NET Runtime on the VPS

SSH into your VPS.

ssh your-user@your-vps-ip

Install the .NET runtime required by your API.

For .NET 10, follow the official Microsoft install command for your Ubuntu version.

Example structure:

sudo apt update
sudo apt install -y dotnet-runtime-10.0

Verify:

dotnet --info

If your app is an ASP.NET Core API, install the ASP.NET Core runtime:

sudo apt install -y aspnetcore-runtime-10.0

---

2. Create the Obaki app user

Create a dedicated Linux user for the app.

sudo adduser --system --group --home /opt/obaki obaki

Create the app folders:

sudo mkdir -p /opt/obaki/releases
sudo mkdir -p /opt/obaki/shared/logs
sudo chown -R obaki:obaki /opt/obaki

Expected structure:

/opt/obaki/
  releases/
  shared/
    logs/

Later, the deployment will create:

/opt/obaki/current -> /opt/obaki/releases/<release-folder>

---

3. Create the production environment file

Production secrets should live on the VPS, not in GitHub.

Create:

sudo mkdir -p /etc/obaki
sudo nano /etc/obaki/obaki.env

Example:

ASPNETCORE_ENVIRONMENT=Production
ASPNETCORE_URLS=http://127.0.0.1:5000

ConnectionStrings__DefaultConnection=Host=localhost;Port=5432;Database=obaki;Username=obaki;Password=change-this

Resend__ApiKey=re_xxxxxxxxxxxxxxxxx
Email__From=no-reply@yourdomain.com

ExternalProvider__BaseUrl=https://example.com/api
ExternalProvider__ApiKey=change-this

Use __ for nested .NET configuration.

Example:

Resend__ApiKey=re_xxx

maps to:

builder.Configuration["Resend:ApiKey"]

Example:

ConnectionStrings__DefaultConnection=Host=localhost;Database=obaki;Username=obaki;Password=secret

maps to:

builder.Configuration.GetConnectionString("Default")

Lock down the file:

sudo chown root:obaki /etc/obaki/obaki.env
sudo chmod 640 /etc/obaki/obaki.env

Do not commit .env.

Your repository should only have:

.env.example
appsettings.json
appsettings.Development.json

---

4. Create the systemd service

Create the service file:

sudo nano /etc/systemd/system/obaki.service

Paste:

[Unit]
Description=Obaki .NET API
After=network.target

[Service]
WorkingDirectory=/opt/obaki/current
ExecStart=/usr/bin/dotnet /opt/obaki/current/Obaki.Api.dll
Restart=always
RestartSec=5
KillSignal=SIGINT
SyslogIdentifier=obaki
User=obaki

EnvironmentFile=/etc/obaki/obaki.env
Environment=DOTNET_GCHeapHardLimitPercent=40

[Install]
WantedBy=multi-user.target

Important:

/opt/obaki/current/Obaki.Api.dll

must match your actual published DLL name.

Examples:

Obaki.Api.dll
Obaki.Server.dll
Obaki.WebApi.dll

Reload systemd:

sudo systemctl daemon-reload
sudo systemctl enable obaki

The app may not start yet because /opt/obaki/current does not exist until the first deployment.

---

5. Create the API subdomain in Cloudflare

Create a subdomain for the Obaki API.

Example:

api.jjosh.dev

In Cloudflare:

Cloudflare
  -> Your domain
  -> DNS
  -> Records
  -> Add record

Add this DNS record:

Type: A
Name: api
IPv4 address: your VPS public IP
Proxy status: DNS only
TTL: Auto

Example:

A    api    123.123.123.123

This creates:

api.jjosh.dev

Start with:

DNS only

This makes debugging easier because Caddy can directly request and manage the TLS certificate.

After everything works, you can switch the record to:

Proxied

Recommended Cloudflare SSL setting:

SSL/TLS
  -> Overview
  -> Full (strict)

Caddy automatically gets a valid Let’s Encrypt certificate when the DNS record points to your VPS correctly.

If Full (strict) fails during first setup, temporarily use:

Full

Then switch back to:

Full (strict)

Final DNS flow:

api.jjosh.dev
  -> Cloudflare DNS
  -> VPS public IP
  -> Caddy
  -> 127.0.0.1:5000
  -> Obaki .NET API

Do not expose the .NET API directly to the internet.

Keep Obaki bound to:

127.0.0.1:5000

Only Caddy should listen publicly on ports:

80
443

---

6. Configure Caddy reverse proxy

Edit your Caddyfile:

sudo nano /etc/caddy/Caddyfile

Example:

api.jjosh.dev {
    reverse_proxy 127.0.0.1:5000
}

If Obaki shares the same VPS with ntfy:

ntfy.yourdomain.com {
    reverse_proxy 127.0.0.1:8080
}

api.yourdomain.com {
    reverse_proxy 127.0.0.1:5000
}

Reload Caddy:

sudo systemctl reload caddy

Check status:

sudo systemctl status caddy

---

7. Create a deploy user

Use a deploy user for GitHub Actions.

sudo adduser deploy

Add the deploy user to the obaki group:

sudo usermod -aG obaki deploy

Allow the deploy user to write to /opt/obaki:

sudo chown -R obaki:obaki /opt/obaki
sudo chmod -R 775 /opt/obaki

---

8. Allow deploy user to restart only Obaki

Open sudoers safely:

sudo visudo

Add this line:

deploy ALL=NOPASSWD: /bin/systemctl restart obaki, /bin/systemctl is-active obaki, /bin/systemctl status obaki

This allows GitHub Actions to restart only the obaki service.

---

9. Add SSH key for GitHub Actions

On your local machine, create a deploy SSH key:

ssh-keygen -t ed25519 -C "github-actions-obaki" -f obaki_deploy_key

This creates:

obaki_deploy_key
obaki_deploy_key.pub

Copy the public key to the VPS deploy user:

ssh-copy-id -i obaki_deploy_key.pub deploy@your-vps-ip

Test:

ssh -i obaki_deploy_key deploy@your-vps-ip

The private key content goes into GitHub Secrets.

Show the private key:

cat obaki_deploy_key

Copy the full output, including:

-----BEGIN OPENSSH PRIVATE KEY-----
...
-----END OPENSSH PRIVATE KEY-----

---

10. Add GitHub repository secrets

In GitHub:

Repository
  -> Settings
  -> Secrets and variables
  -> Actions
  -> New repository secret

Add:

VPS_HOST=your-vps-ip-or-hostname
VPS_USER=deploy
VPS_PORT=22
VPS_SSH_KEY=<private key content>
VPS_SSH_KNOWN_HOSTS=<known_hosts entry for your VPS, optional but recommended>

VPS_SSH_KNOWN_HOSTS is optional but recommended. If it is not set, the workflow falls back to ssh-keyscan during deployment and validates that a host key was collected.

To pin the host key, create VPS_SSH_KNOWN_HOSTS from a trusted host key line.

The host in this secret must match VPS_HOST, and the port must match VPS_PORT.

For port 22:

ssh-keyscan -p 22 your-vps-ip-or-hostname

For a custom SSH port, use the same port as VPS_PORT. The output should start with [host]:port.

ssh-keyscan -p 2222 your-vps-ip-or-hostname

Verify the fingerprint with your VPS provider or server console before saving it as a GitHub secret.

Do not put production app secrets here unless GitHub Actions truly needs them.

Production app secrets should stay in:

/etc/obaki/obaki.env

---

11. Add GitHub Actions deployment workflow

Create this file in your repository:

.github/workflows/deploy.yml

Paste:

name: Deploy Obaki API

on:
  push:
    branches:
      - master
  workflow_dispatch:

permissions:
  contents: read

concurrency:
  group: obaki-production
  cancel-in-progress: false

jobs:
  deploy:
    runs-on: ubuntu-latest
    environment: production

    steps:
      - name: Checkout
        uses: actions/checkout@v4

      - name: Setup .NET
        uses: actions/setup-dotnet@v4
        with:
          dotnet-version: '10.0.x'

      - name: Restore
        run: dotnet restore

      - name: Build
        run: dotnet build --configuration Release --no-restore

      - name: Test
        run: dotnet test --configuration Release --no-build

      - name: Publish
        run: |
          dotnet publish ./src/Obaki.Api/Obaki.Api.csproj \
            --configuration Release \
            --output ./publish

      - name: Configure SSH
        env:
          VPS_HOST: ${{ secrets.VPS_HOST }}
          VPS_PORT: ${{ secrets.VPS_PORT }}
          VPS_USER: ${{ secrets.VPS_USER }}
          VPS_SSH_KEY: ${{ secrets.VPS_SSH_KEY }}
          VPS_SSH_KNOWN_HOSTS: ${{ secrets.VPS_SSH_KNOWN_HOSTS }}
        run: |
          set -eo pipefail

          require_secret() {
            if [ -z "$2" ]; then
              echo "::error::$1 is required for deployment."
              exit 1
            fi
          }

          require_secret "VPS_HOST" "$VPS_HOST"
          require_secret "VPS_PORT" "$VPS_PORT"
          require_secret "VPS_USER" "$VPS_USER"
          require_secret "VPS_SSH_KEY" "$VPS_SSH_KEY"

          set -u

          HOST="$VPS_HOST"
          PORT="$VPS_PORT"
          LOOKUP_HOST="$HOST"
          SSH_KEY_FILE="$HOME/.ssh/deploy_key"
          KNOWN_HOSTS_FILE="$HOME/.ssh/known_hosts"

          if [ "$PORT" != "22" ]; then
            LOOKUP_HOST="[$HOST]:$PORT"
          fi

          mkdir -p "$HOME/.ssh"
          printf '%s\n' "$VPS_SSH_KEY" | tr -d '\r' > "$SSH_KEY_FILE"
          chmod 600 "$SSH_KEY_FILE"

          if [ -n "$VPS_SSH_KNOWN_HOSTS" ]; then
            printf '%s\n' "$VPS_SSH_KNOWN_HOSTS" | tr -d '\r' > "$KNOWN_HOSTS_FILE"
          else
            echo "::warning::VPS_SSH_KNOWN_HOSTS is not set. Falling back to ssh-keyscan for $HOST:$PORT."

            if ! ssh-keyscan -p "$PORT" "$HOST" > "$KNOWN_HOSTS_FILE"; then
              echo "::error::ssh-keyscan could not collect a host key for $HOST:$PORT. Check VPS_HOST, VPS_PORT, and VPS firewall rules."
              exit 1
            fi
          fi

          chmod 600 "$KNOWN_HOSTS_FILE"

          if ! ssh-keygen -F "$LOOKUP_HOST" -f "$KNOWN_HOSTS_FILE" >/dev/null; then
            echo "::error::VPS_SSH_KNOWN_HOSTS does not contain a host key for $LOOKUP_HOST. Regenerate it with: ssh-keyscan -p $PORT $HOST"
            exit 1
          fi

          ssh -i "$SSH_KEY_FILE" -p "$PORT" \
            -o BatchMode=yes \
            -o ConnectTimeout=10 \
            -o StrictHostKeyChecking=yes \
            -o UserKnownHostsFile="$KNOWN_HOSTS_FILE" \
            -o IdentitiesOnly=yes \
            "$VPS_USER@$HOST" \
            "true"

      - name: Deploy to VPS
        env:
          VPS_HOST: ${{ secrets.VPS_HOST }}
          VPS_PORT: ${{ secrets.VPS_PORT }}
          VPS_USER: ${{ secrets.VPS_USER }}
        run: |
          set -euo pipefail

          RELEASE=$(date +%Y%m%d%H%M%S)-${GITHUB_SHA::7}
          REMOTE_RELEASE="/opt/obaki/releases/$RELEASE"
          SSH_KEY_FILE="$HOME/.ssh/deploy_key"
          KNOWN_HOSTS_FILE="$HOME/.ssh/known_hosts"
          LOOKUP_HOST="$VPS_HOST"

          if [ "$VPS_PORT" != "22" ]; then
            LOOKUP_HOST="[$VPS_HOST]:$VPS_PORT"
          fi

          if ! ssh-keygen -F "$LOOKUP_HOST" -f "$KNOWN_HOSTS_FILE" >/dev/null; then
            echo "::error::Deploy step cannot find a known_hosts entry for $LOOKUP_HOST. Check the Configure SSH step and VPS_SSH_KNOWN_HOSTS secret."
            exit 1
          fi

          SSH_COMMAND=(
            ssh
            -i "$SSH_KEY_FILE"
            -p "$VPS_PORT"
            -o BatchMode=yes
            -o StrictHostKeyChecking=yes
            -o UserKnownHostsFile="$KNOWN_HOSTS_FILE"
            -o IdentitiesOnly=yes
          )
          RSYNC_SSH_COMMAND="ssh -i $SSH_KEY_FILE -p $VPS_PORT -o BatchMode=yes -o StrictHostKeyChecking=yes -o UserKnownHostsFile=$KNOWN_HOSTS_FILE -o IdentitiesOnly=yes"

          "${SSH_COMMAND[@]}" \
            "$VPS_USER@$VPS_HOST" \
            "mkdir -p $REMOTE_RELEASE"

          rsync -az --delete \
            -e "$RSYNC_SSH_COMMAND" \
            ./publish/ \
            "$VPS_USER@$VPS_HOST:$REMOTE_RELEASE/"

          "${SSH_COMMAND[@]}" \
            "$VPS_USER@$VPS_HOST" "
              set -eu

              PREVIOUS=\$(readlink -f /opt/obaki/current 2>/dev/null || true)
              rollback() {
                if [ -n \"\$PREVIOUS\" ]; then
                  ln -sfn \"\$PREVIOUS\" /opt/obaki/current
                  sudo systemctl restart obaki || true
                fi

                exit 1
              }

              ln -sfn $REMOTE_RELEASE /opt/obaki/current

              if ! sudo systemctl restart obaki; then
                rollback
              fi

              if ! sudo systemctl is-active obaki; then
                rollback
              fi

              for ATTEMPT in \$(seq 1 30); do
                if curl --fail --silent --show-error --max-time 2 http://127.0.0.1:5000/health/ready >/dev/null; then
                  break
                fi

                if [ \"\$ATTEMPT\" -eq 30 ]; then
                  rollback
                fi

                sleep 2
              done

              CURRENT=\$(readlink -f /opt/obaki/current)
              COUNT=0

              for RELEASE_DIR in \$(ls -1dt /opt/obaki/releases/*/); do
                RELEASE_DIR=\${RELEASE_DIR%/}

                if [ \"\$RELEASE_DIR\" = \"\$CURRENT\" ]; then
                  continue
                fi

                COUNT=\$((COUNT + 1))

                if [ \"\$COUNT\" -gt 5 ]; then
                  rm -rf \"\$RELEASE_DIR\"
                fi
              done

Change this line to match your actual project path:

dotnet publish ./src/Obaki.Api/Obaki.Api.csproj \

Change this systemd line if your DLL name is different:

ExecStart=/usr/bin/dotnet /opt/obaki/current/Obaki.Api.dll

---

12. First deployment

Push to master:

git add .
git commit -m "Add Obaki VPS deployment workflow"
git push origin main

Then check GitHub Actions.

After deployment finishes, check the VPS:

sudo systemctl status obaki

View logs:

journalctl -u obaki -f

Test locally on the VPS:

curl http://127.0.0.1:5000

Test through Caddy:

curl https://api.yourdomain.com

---

13. Rollback

List releases:

ls -lah /opt/obaki/releases

Switch back to an older release:

sudo ln -sfn /opt/obaki/releases/OLD_RELEASE_FOLDER /opt/obaki/current
sudo systemctl restart obaki

Check:

sudo systemctl status obaki

---

14. Clean old releases

Keep only the latest 5 releases:

cd /opt/obaki/releases
ls -1dt */ | tail -n +6 | xargs -r rm -rf

You can add this cleanup later to GitHub Actions after deployment succeeds.

Example:

      - name: Clean old releases
        run: |
          ssh -i ~/.ssh/deploy_key -p "${{ secrets.VPS_PORT }}" \
            "${{ secrets.VPS_USER }}@${{ secrets.VPS_HOST }}" "
              cd /opt/obaki/releases &&
              ls -1dt */ | tail -n +6 | xargs -r rm -rf
            "

---

15. Recommended .NET background worker rules

For Obaki background workers:

Worker 1:
- polls outbox every 2 minutes
- sends emails in small batches
- marks sent / failed
- retries with backoff

Worker 2:
- checks external endpoint every 2 minutes
- stores last seen data
- avoids reprocessing old data

Use PeriodicTimer:

protected override async Task ExecuteAsync(CancellationToken stoppingToken)
{
    using var timer = new PeriodicTimer(TimeSpan.FromMinutes(2));

    while (await timer.WaitForNextTickAsync(stoppingToken))
    {
        try
        {
            await DoWorkAsync(stoppingToken);
        }
        catch (Exception ex)
        {
            logger.LogError(ex, "Obaki background worker failed.");
        }
    }
}

Avoid:

while (true)
Task.Delay without cancellation token
loading all rows into memory
sending thousands of emails in one batch
unbounded logs

---

16. Recommended outbox processing

Use bounded batches.

Example:

Every 2 minutes:
1. Fetch 50-100 pending messages.
2. Mark them as Processing.
3. Send using Resend or SMTP provider.
4. Mark successful messages as Sent.
5. Mark failed messages as Failed.
6. Retry failed messages later with backoff.

Do not send directly inside the public API request.

Good flow:

User action
  -> API saves message to database
  -> API returns success
  -> Outbox worker sends email later

---

17. Useful commands

Restart Obaki:

sudo systemctl restart obaki

Check status:

sudo systemctl status obaki

Follow logs:

journalctl -u obaki -f

Check Caddy:

sudo systemctl status caddy

Reload Caddy:

sudo systemctl reload caddy

Check listening ports:

sudo ss -tulpn

Check memory:

free -h

Check disk:

df -h

---

18. Final production layout

/etc/obaki/
  obaki.env

/opt/obaki/
  current -> /opt/obaki/releases/<latest>
  releases/
    20260704130000-abc1234/
    20260704150000-def5678/
  shared/
    logs/

/etc/systemd/system/
  obaki.service

/etc/caddy/
  Caddyfile

---

19. What belongs where

GitHub repository:

source code
GitHub Actions workflow
appsettings.json
appsettings.Development.json
.env.example

GitHub Secrets:

VPS_HOST
VPS_USER
VPS_PORT
VPS_SSH_KEY
VPS_SSH_KNOWN_HOSTS

VPS environment file:

/etc/obaki/obaki.env

Production secrets:

database connection string
Resend API key
JWT signing secret
external API keys
email sender config

Do not commit production secrets. ssh-copy-id is often not available on Windows. Also, deploy@your-vps-ip is a placeholder. Replace it with your real VPS IP.

Example:

ssh-copy-id -i obaki_deploy_key.pub deploy@123.123.123.123

Not:

ssh-copy-id -i obaki_deploy_key.pub deploy@your-vps-ip If you are on Windows, do it manually

On your PC, open PowerShell where the key files exist.

Show the public key:

Get-Content .\obaki_deploy_key.pub

Copy the full output. It looks like:

ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAI… github-actions-obaki

Now SSH into your VPS using your normal VPS user:

ssh root@YOUR_VPS_IP

or:

ssh your-user@YOUR_VPS_IP

Create the deploy user if not yet created:

sudo adduser deploy

Create the SSH folder:

sudo mkdir -p /home/deploy/.ssh sudo nano /home/deploy/.ssh/authorized_keys

Paste the public key there.

Then fix permissions:

sudo chown -R deploy:deploy /home/deploy/.ssh sudo chmod 700 /home/deploy/.ssh sudo chmod 600 /home/deploy/.ssh/authorized_keys

Now exit VPS:

exit

Test from your PC:

ssh -i .\obaki_deploy_key deploy@YOUR_VPS_IP

Example:

ssh -i .\obaki_deploy_key deploy@123.123.123.123 If PowerShell says key permissions are too open

Run:

icacls .\obaki_deploy_key /inheritance:r icacls .\obaki_deploy_key /grant:r “$env:USERNAME:R”

Then test again:

ssh -i .\obaki_deploy_key deploy@YOUR_VPS_IP Correct expected result

This should log you into the VPS as:

deploy

Then this command should show:

whoami

Output:

deploy Most likely problem

You either used the placeholder:

your-vps-ip

or Windows does not have:

ssh-copy-id

Manual authorized_keys setup fixes it.