Notary client configuration file

This document is for power users of the Notary client who want to facilitate CLI interaction or specify custom options.

The configuration file for Notary client normally resides at ~/.notary/config.json, but the path to a different configuration file can be specified using the -c or --configFile command line flag.

Overview of the file

In addition to the configuration file format, please see the optional password environment variables that the Notary client can take for ease of use.

Here is a full client configuration file example; please click on the top level JSON keys to learn more about the configuration section corresponding to that key:

{
  "trust_dir" : "~/.docker/trust",
  "remote_server": {
    "url": "https://my-notary-server.my-private-registry.com",
    "root-ca": "./fixtures/root-ca.crt",
    "tls_client_cert": "./fixtures/secure.example.com.crt",
    "tls_client_key": "./fixtures/secure.example.com.crt"
  }
  "trust_pinning": {
    "certs": {
      "docker.com/notary": ["49cf5c6404a35fa41d5a5aa2ce539dfee0d7a2176d0da488914a38603b1f4292"]
    }
  }
}

trust_dir section (optional)

The trust_dir specifies the location (as an absolute path or a path relative to the directory of the configuration file) where the TUF metadata and private keys will be stored.

This is normally defaults to ~/.notary, but specifying ~/.docker/trust facilitates interoperability with content trust.

Note that this option can be overridden with the command line flag --trustDir.

remote_server section (optional)

The remote_server specifies how to connect to a Notary server to download metadata updates and publish metadata changes.

Remote server example:

"remote_server": {
  "url": "https://my-notary-server.my-private-registry.com",
  "root-ca": "./fixtures/root-ca.crt",
  "tls_client_cert": "./fixtures/secure.example.com.crt",
  "tls_client_key": "./fixtures/secure.example.com.crt"
}
Parameter Required Description
url no URL of the Notary server: defaults to https://notary.docker.io This configuration option can be overridden with the command line flag `-s` or `--server`.
root-ca no

The path to the file containing the root CA with which to verify the TLS certificate of the Notary server, for example if it is self-signed. The path is relative to the directory of the configuration file.

This configuration option can overridden with the command line flag `--tlscacert`, which would specify a path relative to the current working directory where the Notary client is invoked.

tls_client_cert no

The path to the client certificate to use for mutual TLS with the Notary server. Must be provided along with tls_client_key or not provided at all. The path is relative to the directory of the configuration file.

This configuration option can overridden with the command line flag `--tlscert`, which would specify a path relative to the current working directory where the Notary client is invoked.

tls_client_key no

The path to the client key to use for mutual TLS with the Notary server. Must be provided along with tls_client_cert or not provided at all. The path is relative to the directory of the configuration file.

This configuration option can overridden with the command line flag `--tlskey`, which would specify a path relative to the current working directory where the Notary client is invoked.

trust_pinning section (optional)

The trust_pinning specifies how to bootstrap trust for the root of a Notary client’s trusted collection.

This section is optional, Notary will use TOFU over HTTPS by default and trust certificates in the downloaded root file.

In this section, one can provide specific certificates to pin to, or a CA to pin to as a root of trust for a GUN. Multiple sections can be specified, but the pinned certificates will take highest priority for validation, followed by the pinned CA, followed by TOFUS (TOFU over HTTPS). The diagram below describes this validation flow:

Trust pinning flow

Only one trust pinning option will be used to validate a GUN even if multiple sections are specified, and any validation failure will result in a failed bootstrapping of the repo.

Parameter Required Description
certs no

Mapping of GUN to certificate IDs to pin to. Both are strings in the JSON object.

ca no

Mapping of GUN prefixes to filepaths containing the root CA file with which to verify the certificates in the root file. This file can contain multiple root certificates, bundled in separate PEM blocks. The path is relative to the directory of the configuration file.

disable_tofu no

Boolean value determining whether to use trust on first use when bootstrapping validation on a collection's root file. This keeps TOFUs on by default.

Environment variables (optional)

The following environment variables containing signing key passphrases can be used to facilitate Notary client CLI interaction. If provided, these passwords will be used initially to sign TUF metadata. If the passphrase is incorrect, you will be prompted to enter the correct passphrase.

Environment Variable Description
NOTARY_ROOT_PASSPHRASE The root/offline key passphrase
NOTARY_TARGETS_PASSPHRASE The targets (an online) key passphrase
NOTARY_SNAPSHOT_PASSPHRASE The snapshot (an online) key passphrase
NOTARY_DELEGATION_PASSPHRASE The delegation (an online) key passphrase

Please note that if provided, the passphrase in NOTARY_DELEGATION_PASSPHRASE will be attempted for all delegation roles that notary attempts to sign with.