# Learn to Build a Photo Captioning Streamlit Application with Amazon Bedrock LLMs

In this article, we will walk through how to create an AI-powered photo captioning app. First, let's create our app.

## Creating LLM integrated Steamlit app

You can download the code for the app from the following GitHub repository:

[https://github.com/Vivek-Rathee/PhotoCaptioner](https://github.com/Vivek-Rathee/PhotoCaptioner)

But before deploying, let's understand what's happening inside the `AIPCWA.py` file.

First, you import the necessary packages mentioned in the file. You will need to pip install these packages if you don't already have them on your system.

Then set the page configurations for Streamlit, and load the CLIP model and processor. Next, add an AWS profile that has the necessary permissions to access AWS Rekognition and Bedrock, and create clients for the respective services.

Add a modelID of the LLM you would like to use, which you can find on the AWS Bedrock models page.

Create a function that converts the uploaded images to bytes and calls Rekognition to detect labels.

Next, refine the caption based on the user's choice of platform. Create the body as a dictionary, then serialize it to JSON and encode it as bytes. Read and decode the response, extract the refined caption from the response, and remove any prefatory text.

At last, create your Streamlit app, and with it, you have a functioning code for your AI-enhanced photo captioning app.

Test locally using VS Code with "streamlit run yourAppName.py". You'll need to configure the profile you mentioned in the code. You can use the AWS extension for configuring your profile in VS Code.

## Hosting your Streamlit app on your custom domain.

### Create an EC2 instance with the following configuration:

* **OS:** Amazon AMI Linux 2023
    
* **Network/Security Group:** Allow internet access on ports 80, 443, and 8501 (port on which streamlit runs)
    
* **Storage:** 100GB (as dependencies need space)
    

### System Update and Python Environment Setup

1. **Switch to the root user**:
    
    ```plaintext
    sudo su
    ```
    
2. **Update all installed packages to their latest version**:
    
    ```plaintext
    yum update -y
    ```
    
3. **Upgrade the operating system to the latest release**:
    
    ```plaintext
    yum upgrade -y
    ```
    
4. **Create a Python virtual environment**:
    
    ```plaintext
    python3 -m venv venv
    ```
    
5. **Activate the Python virtual environment**:
    
    ```plaintext
    source venv/bin/activate
    ```
    

### Install Python Packages

6. **Install the Python package installer (pip)**:
    
    ```plaintext
    yum install -y python3-pip
    ```
    
7. **Install specific versions of PyTorch and related libraries**:
    
    ```plaintext
    python3 -m pip install torch==1.13.1 torchvision==0.14.1 torchaudio==0.13.1 --index-url https://download.pytorch.org/whl/cpu
    ```
    
8. **Install Streamlit, ignoring any previously installed versions**:
    
    ```plaintext
    python3 -m pip install --ignore-installed streamlit
    ```
    
9. **Install Boto3, the Amazon Web Services (AWS) SDK for Python**:
    
    ```plaintext
    python3 -m pip install boto3 
    ```
    
10. **Install Pillow, a Python Imaging Library (PIL) fork**:
    
    ```plaintext
    python3 -m pip install pillow
    ```
    
11. **Install the Transformers library**:
    
    ```plaintext
    python3 -m pip install transformers
    ```
    

### Git and Project Setup

12. **Install Git**:
    
    ```plaintext
    yum install git
    ```
    
13. **Clone the PhotoCaptioner repository**:
    
    ```plaintext
    git clone https://github.com/Vivek-Rathee/PhotoCaptioner.git
    ```
    
14. **Navigate to the project directory**:
    
    ```plaintext
    cd PhotoCaptioner
    ```
    

### AWS Configuration

15. **Configure AWS CLI with your user profile**:
    
    ```plaintext
    aws configure --profile YourUserProfile
    ```
    
    Follow the prompts to enter your AWS credentials:
    
    ```plaintext
    Access Key ID [None]: Your Access Key ID
    AWS Secret Access Key [None]: Your Secret Access Key
    Default region name [None]: us-east-1
    Default output format [None]: json
    ```
    

### Setting up HTTP nginx web server

16. **Install nginx**:
    
    ```plaintext
    yum install nginx -y
    ```
    
17. **Install Certbot**:
    
    ```plaintext
    yum install certbot -y
    ```
    
18. **Stop nginx**:
    
    ```plaintext
    sudo systemctl stop nginx
    ```
    
19. **Obtain SSL certificates for your domain**:
    
    ```plaintext
    sudo certbot certonly --standalone -d yourdomain.com
    ```
    
20. **Clear and edit nginx configuration file**:
    
    ```plaintext
    sudo sh -c 'echo -n > /etc/nginx/nginx.conf'
    nano /etc/nginx/nginx.conf
    ```
    
21. **Edit the nginx configuration file**:
    
    ```plaintext
    user nginx;
    worker_processes auto;
    error_log /var/log/nginx/error.log;
    pid /run/nginx.pid;
    
    events {
        worker_connections 1024;
    }
    
    http {
        include /etc/nginx/mime.types;
        default_type application/octet-stream;
    
        log_format main '$remote_addr - $remote_user [$time_local] "$request" '
                          '$status $body_bytes_sent "$http_referer" '
                          '"$http_user_agent" "$http_x_forwarded_for"';
    
        access_log /var/log/nginx/access.log main;
    
        sendfile on;
        keepalive_timeout 65;
        include /etc/nginx/conf.d/*.conf;
    
        map $http_upgrade $connection_upgrade {
            default upgrade;
            '' close;
        }
    
        upstream backend {
            server 127.0.0.1:8501;
            keepalive 64;
        }
    
        server {
            listen 80;
            server_name aipc.vivekrathee.com;
    
            location / {
                return 301 https://$host$request_uri;
            }
        }
    
        server {
            listen 443 ssl;
            server_name aipc.vivekrathee.com;
    
            ssl_certificate /etc/letsencrypt/live/yourdomain.com/fullchain.pem;
            ssl_certificate_key /etc/letsencrypt/live/yourdomain.com/privkey.pem;
    
            location / {
                proxy_pass http://backend;
                proxy_http_version 1.1;
                proxy_set_header Upgrade $http_upgrade;
                proxy_set_header Connection $connection_upgrade;
                proxy_set_header Host $host;
                proxy_cache_bypass $http_upgrade;
                proxy_set_header X-Real-IP $remote_addr;
                proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
                proxy_set_header X-Forwarded-Proto $scheme;
                client_max_body_size 20M;  # Adjust this value as necessary
            }
        }
    
        types_hash_max_size 2048;
        types_hash_bucket_size 128;
    }
    ```
    

### Restart and Enable nginx

22. **Restart nginx**:
    
    ```plaintext
    sudo systemctl restart nginx
    ```
    
23. **Enable nginx to start on boot**:
    
    ```plaintext
    sudo systemctl enable nginx
    ```
    

### Create the Shell Script

24. **Create a new file named**`run_`[`streamlit.sh`](http://streamlit.sh) in the same directory:
    
    ```plaintext
    nano run_streamlit.sh
    ```
    
    Add the following content to the file:
    
    ```plaintext
    while true
    do
        nohup streamlit run AIPCWA.py &
        wait $!
        sleep 5
    done
    ```
    
25. **Make the shell script executable**:
    
    ```plaintext
    chmod +x run_streamlit.sh
    ```
    

### Using tmux to Run the Script

26. **Install tmux**:
    
    ```plaintext
    sudo yum install tmux
    ```
    
27. **Create a new tmux session named**`streamlit_session`:
    
    ```plaintext
    tmux new -s streamlit_session
    ```
    
28. **Run the shell script in the background**:
    
    ```plaintext
    nohup ./run_streamlit.sh > streamlit.log 2>&1 &
    ```
    
29. **Detach from the tmux session** by pressing `Ctrl+b` followed by `d`.
    

Conclusion: After following the above prcess you should have an AI powered Photo Captioning app running on your custom domain (like the one you can use here [https://aipc.vivekrathee.com/](https://aipc.vivekrathee.com/)).

[**#AIForTomorrow**](https://hashnode.com/n/aifortomorrow)