Ticket #15: Add docker-compose for Local Orchestration

[PuneethM-06]

Description

Define linux-sysmonitor as a Docker Compose service to simplify local deployment and orchestration. Configure environment variables, persistent storage for logs, and a restart policy. Optionally, add a second service to practice inter-container networking.

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Tasks

• Create a docker-compose.yml file in the project root.
• Define the sysmonitor service using the local Dockerfile.
• Configure a named volume to persist log files outside the container.
• Mount the volume to the application's log directory (e.g., /app/logs).
• Pass configuration using environment variables (e.g., LOG_LEVEL, CHECK_INTERVAL).
• Add a restart policy:

  restart: unless-stopped

• (Stretch Goal) Add a second service (e.g., nginx) and configure the health-check script to communicate with it using the Docker Compose network.
• Start the application:

  docker compose up

• Verify log persistence:

  docker compose down
  docker compose up

• Confirm previously generated logs are still available.

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Acceptance Criteria

• docker compose up starts all configured services successfully.
• The sysmonitor service runs without errors.
• Log files persist across container restarts using the named volume.
• Environment variables are correctly injected into the container.
• (Stretch Goal) Services can communicate using the default Docker Compose network.

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Commit Message

feat: add docker-compose for local orchestration (closes #15)

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Why This Matters

Docker Compose is the standard tool for running multi-container applications during development. It introduces concepts that closely align with Kubernetes, including:

• Service definitions
• Named volumes
• Environment variable injection
• Container networking
• Restart policies

Completing this ticket prepares you for Kubernetes fundamentals, where these concepts evolve into Pods, PersistentVolumeClaims (PVCs), ConfigMaps, and Services.

Interview Tip: Be prepared to explain why Docker Compose is ideal for local development but not sufficient for production. Common limitations include single-host deployment, limited scalability, and the absence of built-in orchestration features such as automatic scheduling, self-healing, and rolling updates.

[PuneethM-06]

The restart policy has been configured as required by the ticket. The current health-check.sh is a one-shot script that exits after completing its checks, so the container will continuously restart under this policy. A future enhancement will convert the script into a long-running monitoring process that makes use of CHECK_INTERVAL.

[PuneethM-06]

• Explicitly adding depends_on: as a safer fallback, if webserver starts before sysmonitor because of which ping may fail in health-check.sh

[PuneethM-06]

This comment verifies that Docker compose up and Network connectivity is established between both the containers

[PuneethM-06]

Enhancement in PR

• feat: add Docker Compose support for local orchestration (closes #15) linux-sysmonitor#20

[PuneethM-06]

@gayathrii12 Can I get a review for this ticket?