Configuration

All the configuration for the server is done through a library called Viper which allows for the parsing of configuration files and accessing them in a simple and idiomatic way. Viper supports reading configuration from JSON, TOML, YAML, HCL, envfiles, and Java properties files. As well as, command line flags and environment variables. Every field has a default configuration value if the field is not overridden by the configuration file.

File Structure

The configuration file has three sections: http, logging, and database. Each section is responsible for a different section of the server. Below are the configuration keys and their descriptions.

HTTP

This configures the host and port the server will listen on. If the port is in use, then an error will be thrown and the server will exit. It also configures the domain in which the server can be accessed. This can either be an IP or domain, but must contain the scheme (either http or https). Finally, you can specify whether to delete all of the uploaded files on the starting of the server. You could also do this manually as the files are stored in the uploaded folder in the directory where the server is running.

Logging

This configures the logger with the level and output format. The log levels are trace, debug, info, warn, error, fatal, and panic. The trace level is the most verbose and gives exact insight into what is happening in the server. It should only be used for debugging as it generates mass amounts of logs. The panic level is the least verbose and will never happen on this server. It calls the panic function, causing a stack trace and the server to abruptly halt. The potential formats are text and json. The text format is colored and meant to be human readable. As for JSON, it outputs the same data as text, but in JSON format meant for the parsing by a log aggregator like Prometheus or Logstash.

Database

This configures the host and port to connect to the database. If the server is unable to connect to the database, the server will throw an error and will exit. You must also specify the username, password, and database to use. If an authentication error occurs or the database does not exist, the the server will error and exit. The configuration can specify the SSL connection mode to use. The valid values are disable, allow, prefer, require, verify-ca, and verify-full. Disable does not use SSL at all, allow will use it if available, prefer will attempt to use it, but won’t fail if it cannot use SSL. As for require, verify CA, and verify full, they will all enforce SSL, but to varying degrees. Require does no validation on the certificates, verify CA ensures the certificate authority that issued the certificate is valid, and verify full ensures the entire chain is valid.

Configuration Keys

Below are all the keys and their defaults in the configuration file. The section is the enclosing field in which the keys exist.

Section	Key	Type	Description	Default
http	host	string	Address to listen on. Use 0.0.0.0 for all addresses	127.0.0.1
http	port	integer	Port on the server to listen on	8080
http	domain	string	Domain/IP where the service is accessible	http://127.0.0.1:8080
http	reset_files	boolean	Delete all of the files that have been uploaded	false
logging	format	string	Format to log the output in	text
logging	level	string	Set the minimum level to log	info
database	host	string	Address where the database can be accessed	127.0.0.1
database	port	integer	Port the database is listening on	5432
database	ssl	string	Mode to use SSL in	disable
database	username	string	User to access the database as	postgres
database	password	string	Password associated with the username	postgres
database	database	string	Database to write tables to	postgres
database	reset	boolean	Delete the tables if they already exist

Example

While Viper supports HCL, envfiles, and Java properties files, those configuration languages do not support nested values. As such only JSON, TOML, and YAML are able to properly configure the server. To see an example configuration file in YAML, view config.sample.yaml.