FlashPaper is a one-time, encrypted, zero-knowledge, password/secret sharing application focused on simplicity and security. No database or complicated setup required. In this step by step guide I will show you how to install FlashPaper on your Synology NAS using Docker & Portainer.

💡Note: This guide works perfectly with the latest FlashPaper v2.4.0 release.

• STEP 1

Please Support My work by Making a Donation.

• STEP 2

Install Portainer using my step by step guide. If you already have Portainer installed on your Synology NAS, skip this STEP. Attention: Make sure you have installed the latest Portainer version.

• STEP 3

Make sure you have a synology.me Wildcard Certificate. Follow my guide to get a Wildcard Certificate. If you already have a synology.me Wildcard certificate, skip this STEP.

• STEP 4

Go to Control Panel / Login Portal / Advanced Tab / click Reverse Proxy. Follow the instructions in the image below.

• STEP 5

Now click the “Create” button. Follow the instructions in the image below.

• STEP 6

After you click the Create button, the window below will open. Follow the instructions in the image below.

On the General area, set the Reverse Proxy Name description: type in FlashPaper. After that, add the following instructions:

Source:
Protocol: HTTPS
Hostname: flashpaper.yourname.synology.me
Port: 443

Check Enable HSTS

Destination:
Protocol: HTTP
Hostname: localhost
Port: 8135

• STEP 7

On the Reverse Proxy Rules click the Custom Header tab. Click Create and then, from the drop-down menu, click WebSocket. After you click on WebSocket, two Header Names and two Values will be automatically added. Click Save. Follow the instructions in the image below.

• STEP 8

Go to Control Panel / Network / Connectivity tab/ Check Enable HTTP/2 then click Apply. Follow the instructions in the image below.

• STEP 9

Go to Control Panel / Security / Advanced tab/ Check Enable HTTP Compression then click Apply. Follow the instructions in the image below.

• STEP 10

Go to File Station and open the docker folder. Inside the docker folder, create one new folder and name it flashpaper. Follow the instructions in the image below.
Note: Be careful to enter only lowercase, not uppercase letters.

• STEP 11

Log into Portainer using your username and password. On the left sidebar in Portainer, click on Stacks then + Add stack. Follow the instructions in the image below.

• STEP 12

In the Name field type in flashpaper. Follow the instructions in the image below.

Note: Copy Paste the code below in the Portainer Stacks Web editor.

services:
  flashpaper:
    image: ghcr.io/andrewpaglusch/flashpaper:v2
    container_name: FlashPaper
    healthcheck:
      test: ["CMD-SHELL", "nc -z 127.0.0.1 80 || exit 1"]
      interval: 10s
      timeout: 5s
      retries: 3
      start_period: 90s
    volumes:
      - /volume1/docker/flashpaper:/var/www/html/data:rw
    ports:
      - 8135:80
    environment:
      SITE_TITLE: "FlashPaper :: Self-Destructing Message"
      SITE_LOGO: "yourownURLlogo"
      DISPLAY_LOGO: "true"
      DISPLAY_TITLE: "false"
      RETURN_FULL_URL: "true"
      BASE_URL: "https://flashpaper.mariushosting.synology.me"
      MAX_SECRET_LENGTH: "3000"
      ANNOUNCEMENT: ""
      MESSAGES_ERROR_SECRET_TOO_LONG: "Input length too long"
      MESSAGES_SUBMIT_SECRET_HEADER: "Create A Self-Destructing Message"
      MESSAGES_SUBMIT_SECRET_SUBHEADER: ""
      MESSAGES_SUBMIT_SECRET_BUTTON: "Encrypt Message"
      MESSAGES_VIEW_CODE_HEADER: "Self-Destructing URL"
      MESSAGES_VIEW_CODE_SUBHEADER: "Share this URL via email, chat, or another messaging service. It will self-destruct after being viewed once."
      MESSAGES_CONFIRM_VIEW_SECRET_HEADER: "View this secret?"
      MESSAGES_CONFIRM_VIEW_SECRET_BUTTON: "View Secret"
      MESSAGES_VIEW_SECRET_HEADER: "Self-Destructing Message"
      MESSAGES_VIEW_SECRET_SUBHEADER: "This message has been destroyed"
      PRUNE_ENABLED: "true"
      PRUNE_MIN_DAYS: 365
      PRUNE_MAX_DAYS: 730
    restart: on-failure:5

Note: Before you paste the code above in the Web editor area below, change the value for SITE_TITLE and add your own SITE TITLE. You should invent your own Site Title. The name you choose should be inside the quotation marks “”.
Note: Before you paste the code above in the Web editor area below, change the value for SITE_LOGO and add your own URL logo image link.

• STEP 13

Scroll down on the page until you see a button named Deploy the stack. Click on it. Follow the instructions in the image below. The installation process can take up to a few minutes. It will depend on your Internet speed connection.

• STEP 14

If everything goes right, you will see the following message at the top right of your screen: “Success Stack successfully deployed“.

• STEP 15

🟢Please Support My work by Making a Donation. Almost 99,9% of the people that install something using my guides forget to support my work, or just ignore STEP 1. I’ve been very honest about this aspect of my work since the beginning: I don’t run any ADS, I don’t require subscriptions, paid or otherwise, I don’t collect IPs, emails, and I don’t have any referral links from Amazon or other merchants. I also don’t have any POP-UPs or COOKIES. I have repeatedly been told over the years how much I have contributed to the community. It’s something I love doing and have been honest about my passion since the beginning. But I also Need The Community to Support me Back to be able to continue doing this work.

• STEP 16

Now open your browser and type in your HTTPS/SSL certificate like this https://flashpaper.yourname.synology.me In my case it’s https://flashpaper.mariushosting.synology.me If everything goes right, you will see the FlashPaper page. Change the theme to Dark. In the message area, type in your own message, then click Encrypt Message. You also have the option to select a predefined template. Follow the instructions in the image below.

• STEP 17

Copy the URL and Share with Someone! Follow the instructions in the image below.

• STEP 18

Click View Secret to view the message. Once you view the message once, the message is automatically destroyed. This means that, if you access this same link again, you will get a message saying the message has been destroyed.

• STEP 19

Your message at a glance!

Enjoy FlashPaper!

🆘TROUBLESHOOTING

If you encounter issues by using this container, make sure to check out the Common Docker issues article.

Note: Find out how to update the FlashPaper container with the latest image.
Note: How to Back Up Docker Containers on your Synology NAS.
Note: Can I run Docker on my Synology NAS? See the supported models.
Note: How to Free Disk Space on Your NAS if You Run Docker.
Note: How to Schedule Start & Stop For Docker Containers.
Note: How to Activate Email Notifications.
Note: How to Add Access Control Profile on Your NAS.
Note: How to Change Docker Containers Restart Policy.
Note: How to Use Docker Containers With VPN.
Note: Convert Docker Run Into Docker Compose.
Note: How to Clean Docker.
Note: How to Clean Docker Automatically.
Note: Best Practices When Using Docker and DDNS.
Note: Some Docker Containers Need WebSocket.
Note: Find out the Best NAS Models For Docker.
Note: Activate Gmail SMTP For Docker Containers.

This post was updated on Saturday / January 11th, 2025 at 11:46 AM