Config

Turna configuration is decoded into four main sections: loads, preprocess, server, and services.

log_level: info
print: "turna started for {{ .APP_NAME }}"

loads: []
preprocess: []
server: {}
services: []
telemetry: {}

Startup Order

Turna applies configuration and runtime work in this order:

1. Load bootstrap settings from environment variables.
2. Load Turna application config from Consul, Vault, file, and environment sources depending on config_set.
3. Run loads and store loaded data in template memory.
4. Run preprocess modules.
5. Render and write the top-level print message to logs when configured.
6. Start server entrypoints and routers.
7. Start services.

Dynamic loads can update loaded data later. When that happens, Turna refreshes template data and service filters.

Top-Level Fields

Field	Type	Description
log_level	string	Application log level. Default is info.
print	string	Template rendered after loads and preprocess complete.
loads	array	External data loaders. See Loads.
preprocess	array	Pre-start file processors. See Preprocess.
server	object	HTTP/TCP server configuration. See Server.
services	array	Local commands to run. See Services.
telemetry	object	OpenTelemetry exporter settings. See Telemetry.

Telemetry

telemetry configures the global OpenTelemetry meter and tracer providers with github.com/rakunlabs/tell. Metrics and traces are exported over OTLP/gRPC. Without a collector address (and without OTEL_EXPORTER_OTLP_ENDPOINT) the providers are noop, so the telemetry middlewares cost almost nothing.

telemetry:
  collector: otel-collector:4317
  server_name: ""
  tls:
    enabled: false
    insecure_skip_verify: false
    cert_file: ""
    key_file: ""
    ca_file: ""
  metric:
    disabled: false
    default:
      go_runtime: true
  trace:
    disabled: false

Telemetry is recorded by the telemetry middlewares of HTTP, TCP and UDP. Service name and resource attributes follow the standard OTEL_SERVICE_NAME and OTEL_RESOURCE_ATTRIBUTES environment variables.

Bootstrap Settings

Bootstrap settings decide where the Turna config itself is loaded from.

prefix:
  vault: ""
  consul: ""
app_name: turna
config_set:
  consul: false
  vault: false
  file: true

Equivalent environment variables:

APP_NAME=turna
PREFIX_CONSUL=finops
PREFIX_VAULT=secret
CONFIG_SET_CONSUL=false
CONFIG_SET_VAULT=false
CONFIG_SET_FILE=true

The effective loader order is Consul, Vault, file, and environment. Environment variables are always loaded last.

File Config

File loading is enabled by default. Supported extensions are toml, yaml, yml, and json.

Turna looks for a file named after APP_NAME, which defaults to turna, such as turna.yaml. Set CONFIG_FILE to use a specific file name.

CONFIG_FILE=local.yaml turna

Consul And Vault Client Environment

Consul uses github.com/hashicorp/consul/api environment variables. Common options:

Environment variable	Description
CONSUL_HTTP_ADDR	Consul address.
CONSUL_HTTP_TOKEN_FILE	File containing the Consul token.
CONSUL_HTTP_TOKEN	Consul token.
CONSUL_HTTP_AUTH	HTTP basic auth.
CONSUL_HTTP_SSL	Enable TLS.
CONSUL_TLS_SERVER_NAME	TLS server name.
CONSUL_CACERT	CA certificate file.
CONSUL_CAPATH	CA certificate directory.
CONSUL_CLIENT_CERT	Client certificate.
CONSUL_CLIENT_KEY	Client key.
CONSUL_HTTP_SSL_VERIFY	TLS verification toggle.
CONSUL_NAMESPACE	Consul namespace.
CONSUL_PARTITION	Consul partition.

Vault uses github.com/hashicorp/vault/api environment variables. Common options:

Environment variable	Description
VAULT_ADDR	Vault address.
VAULT_TOKEN	Vault token.
VAULT_ROLE_ID	AppRole role ID.
VAULT_ROLE_SECRET	AppRole secret.
VAULT_AGENT_ADDR	Vault agent address.
VAULT_MAX_RETRIES	Retry count.
VAULT_CACERT	CA certificate file.
VAULT_CACERT_BYTES	CA certificate bytes.
VAULT_CAPATH	CA certificate directory.
VAULT_CLIENT_CERT	Client certificate.
VAULT_CLIENT_KEY	Client key.
VAULT_RATE_LIMIT	Client-side rate limit.
VAULT_CLIENT_TIMEOUT	Client timeout.
VAULT_SKIP_VERIFY	Skip TLS verification.
VAULT_TLS_SERVER_NAME	TLS server name.
VAULT_HTTP_PROXY	HTTP proxy.
VAULT_PROXY_ADDR	Proxy address.
VAULT_DISABLE_REDIRECTS	Disable redirects.
VAULT_APPROLE_BASE_PATH	AppRole login path.