Computer Manager API

A basic application for system administrators to keep track of the computers issued by their company. The application provides a REST API to manage computer-related datasets that are stored in a postgres database.

Build

Build binary

go build

Creates the binary computer-manager-api.

Build Docker image

docker build . -t computer-manager-api

Run

docker-compose up

The application listens on port 8080.

http://localhost:8080/

The database can be reached via the DSN postgres://postgres:postgres@localhost:5433/computer_manager_api.

psql postgres://postgres:postgres@localhost:5433/computer_manager_api

Endpoints

Action	HTTP Method	Path	Content-Type	Request Body	Description
Create(Computers)	POST	/computers	application/json	see JSON	Store the data of a new computer
Read(Computers)	GET	/computers/{mac}	none	empty	Get the data of a computer
Update(Computers)	PUT	/computers/{mac}	application/json	like JSON, but field macAddr can be omitted	Update the data of a computer
Delete(Computers)	DELETE	/computers/{mac}	none	empty	Delete the data of a computer
Read All(Computers)	GET	/computers	none	empty	Get the data of all computers
Read All Computers(Employee)	GET	/employees/{employee-abbreviation}/computers	none	empty	Get the data of all assigned computers for an employee

Update(Computers):

• operation does not support update of the MAC address
• operation will fail if any required field (other than MAC address) is not provided in request body
• operation will overwrite optional fields with empty value if field is not provided in request body

Delete(Computers):

• repeatedly calling delete on same resource will return 200

Computer Model JSON

{
  "macAddr": "<MAC address (required)>",
  "computerName": "<computer name (required)>",
  "ipAddr": "<IP address (required)>",
  "employeeAbbr": "<employee abbreviation (optional)>",
  "description": "<description (optional)>"
}

Example Requests

Create

curl localhost:8080/computers \
-X POST \
-H "Content-Type: application/json" \
-d '{"macAddr": "00:1B:44:11:3A:B7", "computerName": "localhorst", "ipAddr": "127.0.0.1", "employeeAbbr": "rpm", "description": "hello :)"}' \
-i

Read

curl localhost:8080/computers/00:1B:44:11:3A:B7 \
-X GET \
-i

Update

curl localhost:8080/computers/00:1B:44:11:3A:B7 \
-X PUT \
-H "Content-Type: application/json" \
-d '{"computerName": "localhorst", "ipAddr": "127.0.0.2", "employeeAbbr": "mmu"}' \
-i

Delete

curl localhost:8080/computers/00:1B:44:11:3A:B7 \
-X DELETE \
-i

Read All

curl localhost:8080/computers \
-X GET \
-i

Read All For Employee

curl localhost:8080/employees/rpm/computers \
-X GET \
-i

Limitations

• MAC address is considered to be unique and used as primary key in the database table
• employee abbreviation is considered to be unique for each employee

Next Steps

• add more tests
• validate and normalize incoming data, i.e. parse types, check constraints, store in standardized representation etc.
  • sanitizing input to prevent SQL injection is not needed since GORM takes care of this
• return meaningful HTTP status codes and responses, especially for client-sided errors
• add client authentication, maybe user management
• enable TLS
• make service more robust, for example with request timeouts and throttling
• add exhaustive logging
• add metrics (Prometheus)
• add readiness and health check endpoints
• support graceful shutdown
• consider using advanced database migration framework like github.com/golang-migrate/migrate
• automate workflows
  • add makefile
  • add CI (GitHub Actions)