Configuration

This guide will help you to know the most important configuration options for the Block Headers Service.

Order of resolving configuration

The configuration is resolved in the following priority

1. Environment variables - the environment variables are prefixed with BHS_ and are in uppercase. They have the highest priority when resolving the configuration. You can override any of the configuration options by setting the environment variable with the same name as the configuration option. For example, to override the http.port configuration option, you can set the BHS_HTTP_PORT environment variable.

2. Configuration file - the configuration file is resolved next. The default configuration file is config.yaml in the working directory. You can also specify custom configuration file path using the -C flag in the command line.

3. If you don't specify the configuration file and environment variables, the default configuration will be used - it's resolved in defaults.go file in the config package. Default configuration from defaults.go is the same as the configuration from config.example.yaml.

Configuration File

There is an example of the configuration in a file called config.example.yaml in the root of the project. You can copy this file to config.yaml and modify it to your needs.

The most important configuration options are:

# Application Configuration Example

# Database Configuration
db:
  # Database engine [sqlite|postgres] (default: sqlite)
  engine: sqlite
  # Path to the database schema
  schema_path: "./database/migrations"
  # Whether prepared DB is enabled
  prepared_db: false
  # Path to prepared database file
  prepared_db_file_path: "./data/blockheaders.csv.gz"

  #sqlite engine configuration
  sqlite:
    file_path: "./data/blockheaders.db"
  #postgres engine configuration, required when engine=postgres
  postgres:
    host: "localhost"
    port: 5432
    user: "user"
    password: "password"
    db_name: "bhs"
    ssl_mode: "disable" #[disable|enable]

# HTTP Configuration
http:
  # HTTP server port
  port: 8080
  # Authentication token
  auth_token: "mQZQ6WmxURxWz5ch"
  # Flag for enabling additional endpoits for profiling with use of pprof
  debug_profiling: true

# Logging Configuration
logging:
  # Logging level
  level: debug
  # Logging format: console/json
  format: console
  # Instance name shown as parameter in logs
  instance_name: block-header-service
  # Flag for enabling origin parameter in logs
  origin: false

# Prometheus metrics configuration
metrics:
  enabled: false

Going through highlighted options:

• The http section contains the auth_token which is used for admin api authentication. This key is used to authenticate the admin api calls.

• The db section contains the engine section which can be set to sqlite or postgresql. The sqlite is the default option. You can also define details about your database in this section.

• The logging section contains options which are used for logging. You can set the level option to debug, info, warn or error. The format option can be set to console or json. The instance_name option is shown as a parameter in logs.

• The metrics section contains the enabled option which is used to enable Prometheus metrics.