Build a named entity recognition app - Docker

Overview

This guide walks you through building and running a named entity recognition (NER) application. You'll build the application using Python with spaCy, and then set up the environment and run the application using Docker.

The application processes input text to identify and print named entities, like people, organizations, or locations.

Prerequisites

You have installed the latest version of Docker Desktop. Docker adds new features regularly and some parts of this guide may work only with the latest version of Docker Desktop.
You have a Git client. The examples in this section use a command-line based Git client, but you can use any client.

Get the sample application

Open a terminal, and clone the sample application's repository using the following command.
console
```
$ git clone https://github.com/harsh4870/Docker-NLP.git
```

Verify that you cloned the repository.

You should see the following files in your Docker-NLP directory.

text

01_sentiment_analysis.py
02_name_entity_recognition.py
03_text_classification.py
04_text_summarization.py
05_language_translation.py
entrypoint.sh
requirements.txt
Dockerfile
README.md

Explore the application code

The source code for the name recognition application is in the Docker-NLP/02_name_entity_recognition.py file. Open 02_name_entity_recognition.py in a text or code editor to explore its contents in the following steps.

Import the required libraries.
python
```
import spacy
```
This line imports the spaCy library. spaCy is a popular library in Python used for natural language processing (NLP).
Load the language model.
python
```
nlp = spacy.load("en_core_web_sm")
```
Here, the spacy.load function loads a language model. The en_core_web_sm model is a small English language model. You can use this model for various NLP tasks, including tokenization, part-of-speech tagging, and named entity recognition.
Specify the main execution block.
python
```
if __name__ == "__main__":
```
This Python idiom ensures that the following code block runs only if this script is the main program. It provides flexibility, allowing the script to function both as a standalone program and as an imported module.
Create an infinite loop for continuous input.
python
```
   while True:
```
This while loop runs indefinitely until it's explicitly broken. It lets the user continuously enter text for entity recognition until they decide to exit.
Get user input.
python
```
input_text = input("Enter the text for entity recognition (type 'exit' to end): ")
```
This line prompts the user to enter text. The program will then perform entity recognition on this text.
Define an exit condition.
python
```
if input_text.lower() == 'exit':
   print("Exiting...")
   break
```
If the user types something, the program converts the input to lowercase and compares it to exit. If they match, the program prints Exiting... and breaks out of the while loop, effectively ending the program.
Perform named entity recognition.
python
```
doc = nlp(input_text)

for ent in doc.ents:
   print(f"Entity: {ent.text}, Type: {ent.label_}")
```
- doc = nlp(input_text): Here, the nlp model processes the user-input text. This creates a Doc object which contains various NLP attributes, including identified entities.
- for ent in doc.ents:: This loop iterates over the entities found in the text.
- print(f"Entity: {ent.text}, Type: {ent.label_}"): For each entity, it prints the entity text and its type (like PERSON, ORG, or GPE).
Create requirements.txt.

The sample application already contains the requirements.txt file to specify the necessary packages that the application imports. Open requirements.txt in a code or text editor to explore its contents.
text
```
# 02 named_entity_recognition
spacy==3.7.2

...
```
Only the spacy package is required for the named recognition application.

Explore the application environment

You'll use Docker to run the application in a container. Docker lets you containerize the application, providing a consistent and isolated environment for running it. This means the application will operate as intended within its Docker container, regardless of the underlying system differences.

To run the application in a container, a Dockerfile is required. A Dockerfile is a text document that contains all the commands you would call on the command line to assemble an image. An image is a read-only template with instructions for creating a Docker container.

The sample application already contains a Dockerfile. Open the Dockerfile in a code or text editor to explore its contents.

The following steps explain each part of the Dockerfile. For more details, see the Dockerfile reference.

Specify the base image.
dockerfile
```
FROM python:3.8-slim
```
This command sets the foundation for the build. python:3.8-slim is a lightweight version of the Python 3.8 image, optimized for size and speed. Using this slim image reduces the overall size of your Docker image, leading to quicker downloads and less surface area for security vulnerabilities. This is particularly useful for a Python-based application where you might not need the full standard Python image.
Set the working directory.
dockerfile
```
WORKDIR /app
```
WORKDIR sets the current working directory within the Docker image. By setting it to /app, you ensure that all subsequent commands in the Dockerfile (like COPY and RUN) are executed in this directory. This also helps in organizing your Docker image, as all application-related files are contained in a specific directory.
Copy the requirements file into the image.
dockerfile
```
COPY requirements.txt /app
```
The COPY command transfers the requirements.txt file from your local machine into the Docker image. This file lists all Python dependencies required by the application. Copying it into the container lets the next command (RUN pip install) install these dependencies inside the image environment.
Install the Python dependencies in the image.
dockerfile
```
RUN pip install --no-cache-dir -r requirements.txt
```
This line uses pip, Python's package installer, to install the packages listed in requirements.txt. The --no-cache-dir option disables the cache, which reduces the size of the Docker image by not storing the unnecessary cache data.
Run additional commands.
dockerfile
```
RUN python -m spacy download en_core_web_sm
```
This step is specific to NLP applications that require the spaCy library. It downloads the en_core_web_sm model, which is a small English language model for spaCy.
Copy the application code into the image.
dockerfile
```
COPY *.py /app
COPY entrypoint.sh /app
```
These commands copy your Python scripts and the entrypoint.sh script into the image's /app directory. This is crucial because the container needs these scripts to run the application. The entrypoint.sh script is particularly important as it dictates how the application starts inside the container.
Set permissions for the entrypoint.sh script.
dockerfile
```
RUN chmod +x /app/entrypoint.sh
```
This command modifies the file permissions of entrypoint.sh, making it executable. This step is necessary to ensure that the Docker container can run this script to start the application.
Set the entry point.
dockerfile
```
ENTRYPOINT ["/app/entrypoint.sh"]
```
The ENTRYPOINT instruction configures the container to run entrypoint.sh as its default executable. This means that when the container starts, it automatically executes the script.

You can explore the entrypoint.sh script by opening it in a code or text editor. As the sample contains several applications, the script lets you specify which application to run when the container starts.

Run the application

To run the application using Docker:

Build the image.

In a terminal, run the following command inside the directory of where the Dockerfile is located.
console
```
$ docker build -t basic-nlp .
```
The following is a break down of the command:
- docker build: This is the primary command used to build a Docker image from a Dockerfile and a context. The context is typically a set of files at a specified location, often the directory containing the Dockerfile.
- -t basic-nlp: This is an option for tagging the image. The -t flag stands for tag. It assigns a name to the image, which in this case is basic-nlp. Tags are a convenient way to reference images later, especially when pushing them to a registry or running containers.
- .: This is the last part of the command and specifies the build context. The period (.) denotes the current directory. Docker will look for a Dockerfile in this directory. The build context (the current directory, in this case) is sent to the Docker daemon to enable the build. It includes all the files and subdirectories in the specified directory.
For more details, see the docker build CLI reference.

Docker outputs several logs to your console as it builds the image. You'll see it download and install the dependencies. Depending on your network connection, this may take several minutes. Docker does have a caching feature, so subsequent builds can be faster. The console will return to the prompt when it's complete.
Run the image as a container.

In a terminal, run the following command.
console
```
$ docker run -it basic-nlp 02_name_entity_recognition.py
```
The following is a break down of the command:
- docker run: This is the primary command used to run a new container from a Docker image.
- -it: This is a combination of two options:
  - -i or --interactive: This keeps the standard input (STDIN) open even if not attached. It lets the container remain running in the foreground and be interactive.
  - -t or --tty: This allocates a pseudo-TTY, essentially simulating a terminal, like a command prompt or a shell. It's what lets you interact with the application inside the container.
- basic-nlp: This specifies the name of the Docker image to use for creating the container. In this case, it's the image named basic-nlp that you created with the docker build command.
- 02_name_entity_recognition.py: This is the script you want to run inside the Docker container. It gets passed to the entrypoint.sh script, which runs it when the container starts.
For more details, see the docker run CLI reference.

[!NOTE]

For Windows users, you may get an error when running the container. Verify that the line endings in the entrypoint.sh are LF (\n) and not CRLF (\r\n), then rebuild the image. For more details, see [Avoid unexpected syntax errors, use Unix style line endings for files in containers](/desktop/troubleshoot-and-support/troubleshoot/topics/#Unexpected-syntax-errors-use-Unix-style-line endings-for-files-in-containers).

You will see the following in your console after the container starts.
console
```
Enter the text for entity recognition (type 'exit' to end):
```

Test the application.

Enter some information to get the named entity recognition.

console

Enter the text for entity recognition (type 'exit' to end): Apple Inc. is planning to open a new store in San Francisco. Tim Cook is the CEO of Apple.

Entity: Apple Inc., Type: ORG
Entity: San Francisco, Type: GPE
Entity: Tim Cook, Type: PERSON
Entity: Apple, Type: ORG

Summary

This guide demonstrated how to build and run a named entity recognition application. You learned how to build the application using Python with spaCy, and then set up the environment and run the application using Docker.

Related information:

Next steps

Explore more natural language processing guides.