Docker Compose環境変数（開発者向けチュートリアル）

What is Docker?

Docker is an open-source system to ease application development, deployment, and running in a system through containerization. Containers are ultra-lightweight portable units that contain both an application and its dependencies so that they run uniformly everywhere—from the developer's machine to production servers. Containers share the kernel of the host's operating system compared to traditional virtual machines and, therefore, are much faster and more efficient.

This would mean a virtualized template in the form of Docker images to make and maintain this set of containers. Furthermore, the platform contains Docker Hub, which is in a way a container image repository. The beauty of this technology lies in its ease of use concerning scalability, portability, and efficiency, which is one reason it has gained such popularity among many DevOps and cloud-based development workflows.

What are Environment Variables in Docker-Compose?

In Docker, an environment variable in the form of a key-value pair is used to configure settings in the containerized application. Such variables can be useful to control the behavior of the application itself without modifying its code, since easily, configurations such as database credentials and API keys or environment modes (for example: development, production) may be changed.

In Docker, an environment attribute can be defined inside the Dockerfile, inside the docker-compose.yml file, or passed at runtime using the docker run command. With the use of environment variables, Docker allows consistent and flexible application deployment across different environments and manages sensitive data like passwords and API tokens more effectively.

How to Create Environment Variables in Docker?

# Dockerfile
# Set the application environment
ENV APP_ENV=development
# Set the database URL
ENV DATABASE_URL=postgres://user:password@db:1234/mydev

version: '3.8'
services:
  myapp:
    image: myapp:latest
    environment:
      - APP_ENV=development
      - DATABASE_URL=postgres://user:password@db:1234/mydev

version: '3.8'
services:
  myapp:
    image: myapp:latest
    environment:
      - APP_ENV=development
      - DATABASE_URL=postgres://user:password@db:1234/mydev

docker run -e APP_ENV=development -e DATABASE_URL=postgres://user:password@db:1234/mydev myapp:latest

docker run -e APP_ENV=development -e DATABASE_URL=postgres://user:password@db:1234/mydev myapp:latest

# .env file
APP_ENV=production
DATABASE_URL=postgres://user:password@db:1234/mydev

# .env file
APP_ENV=production
DATABASE_URL=postgres://user:password@db:1234/mydev

What is IronSecureDoc?

IronSecureDoc for Docker allows developers to easily add a secure document processing capability to their containerized applications. Having learned Docker, you can encapsulate your ASP.NET Core application with IronSecureDoc in a homogeneous environment that makes it easier to deploy and scale. To do this, you'll build a Dockerfile that orchestrates the construction of your ASP.NET Core application using the IronSecureDoc library and possibly other installation scripts or configurations needed to get things working.

Besides, it includes a docker-compose.yml file declaring the service dependencies and environment variables and mapped ports to get on. This makes performing document security tasks much more accessible so your application can run efficiently and effectively in an environment other than the one used during development or production. Installation and Configuration of IronSecureDoc Like in the case of Docker, proper installation and configuration of IronSecureDoc will be needed to properly realize its capabilities: document encryption, redaction, etc.

docker pull ironsoftwareofficial/ironsecuredoc

docker pull ironsoftwareofficial/ironsecuredoc

docker container run --rm -p 8080:8080 -e IronSecureDoc_LicenseKey=<IRONSECUREDOC_LICENSE_KEY> -e ENVIRONMENT=Development -e HTTP_PORTS=8080 ironsoftwareofficial/ironsecuredoc:latest

docker container run --rm -p 8080:8080 -e IronSecureDoc_LicenseKey=<IRONSECUREDOC_LICENSE_KEY> -e ENVIRONMENT=Development -e HTTP_PORTS=8080 ironsoftwareofficial/ironsecuredoc:latest

curl -X 'POST' \
  'http://localhost:8080/v1/document-services/pdfs/encrypt?user_password=demo' \
  -H 'accept: */*' \
  -H 'Content-Type: multipart/form-data' \
  -F 'pdf_file=@test.pdf;type=application/pdf'

curl -X 'POST' \
  'http://localhost:8080/v1/document-services/pdfs/encrypt?user_password=demo' \
  -H 'accept: */*' \
  -H 'Content-Type: multipart/form-data' \
  -F 'pdf_file=@test.pdf;type=application/pdf'

Conclusion

In sum, Docker Compose's environment variables allow the configuration of applications in a very flexible and efficient way since the configuration details are automatically separated from the application code. Consequently, managing different environments such as development, testing, and production is simpler, as only variables such as API keys, database credentials, and settings of an application need to be changed instead of its code.

Using Docker Compose to implement IronSecureDoc utilizes environment variables for securely handling the licensing information, for instance, the IronSecureDoc_LicenseKey, and also in specifying the HTTP ports or the environment mode preferred as either development or production using environment variables. Using environment variables for setup makes it simpler to deploy IronSecureDoc with much less cluttered and hard-to-scale configurations and boosts security.

Advanced features become accessible through a valid license of IronSecureDoc. The application of the tool is strictly dependent on certain terms of use. You can also utilize other high-performance libraries that Iron Software offers to make the development process easier and faster, providing robust functionalities in working with PDFs, text recognition, and barcodes for any conceivable application.