Environment variables

Every variable below has an equivalent flag. A flag on the command line overrides the variable.

Corium variables

Variable	Equivalent flag	Used by
CORIUM_TOKEN	--token	Every client command.
CORIUM_SERVE_TOKEN	--serve-token	transactor, peer-server, postgres-server.
CORIUM_AUTHZ_DB	--authz-db	transactor, peer-server, postgres-server.
CORIUM_STORAGE_KEY	--storage-key	transactor, peer-server, postgres-server, gc, log.
CORIUM_STORE_PLUGINS	--store-plugin	transactor, store verify.
CORIUM_PLUGIN_READ_ONLY_CONFIG	--plugin-read-only-config	transactor.
CORIUM_POSTGRES_READ_ONLY_URL	--postgres-read-only-url	transactor.
CORIUM_S3_READ_ONLY_ACCESS_KEY_ID	--s3-read-only-access-key-id	transactor.
CORIUM_S3_READ_ONLY_SECRET_ACCESS_KEY	--s3-read-only-secret-access-key	transactor.
CORIUM_S3_READ_ONLY_SESSION_TOKEN	--s3-read-only-session-token	transactor.
CORIUM_S3_READ_ONLY_ROLE_ARN	--s3-read-only-role-arn	transactor.
CORIUM_S3_READ_ONLY_ROLE_EXTERNAL_ID	--s3-read-only-role-external-id	transactor.

CORIUM_STORAGE_KEY accepts a comma-separated list, because one process can hold several keys. The same keyring resolves key-encryption keys and protection class keys.

CORIUM_STORE_PLUGINS accepts a path-separator-delimited list of files and directories. Corium searches a directory for platform dynamic libraries only, and it never adds the working directory.

Rust and AWS variables

Variable	Effect
RUST_LOG	Tracing filter, for example corium_transactor=debug,corium_peer=info.
HOSTNAME	Supplies the default --owner value, transactor-$HOSTNAME.
AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY	Primary S3 credentials.
AWS_PROFILE, AWS_REGION, AWS_ENDPOINT_URL	Standard AWS configuration.

The transactor takes its primary S3 credentials from the standard AWS chain, which also covers instance and task roles.

Handling secrets

Process arguments are visible to every user on the host. Three rules follow.

• Put a token, a password, or a connection URL in an environment variable, or in the configuration file.
• Set the mode of a key file and of a configuration file so that only the service user can read them.
• Prefer a file: storage key over an env: storage key. A file has a mode. An environment variable is inherited by child processes.