Notary signer configuration file

Estimated reading time: 5 minutes

This document is for those who are running their own Notary service and want to specify custom options.

Overview

Notary signer requires environment variables to encrypt private keys at rest. It also requires a configuration file, the path to which is specified on the command line using the -config flag.

Here is a full signer configuration file example:

{
  "server": {
    "http_addr": ":4444",
    "grpc_addr": ":7899",
    "tls_cert_file": "./fixtures/notary-signer.crt",
    "tls_key_file": "./fixtures/notary-signer.key",
    "client_ca_file": "./fixtures/notary-server.crt"
  },
  "logging": {
    "level": 2
  },
  "storage": {
    "backend": "mysql",
    "db_url": "user:pass@tcp(notarymysql:3306)/databasename?parseTime=true",
    "default_alias": "passwordalias1"
  },
  "reporting": {
    "bugsnag": {
      "api_key": "c9d60ae4c7e70c4b6c4ebd3e8056d2b8",
      "release_stage": "production"
    }
  }
}

For details on the reporting and logging sections, see the documentation on common Notary configuration sections.

server section (required)

“server” in this case refers to Notary signer’s HTTP/GRPC server, not “Notary server”.

Example:

{
  "server": {
    "http_addr": ":4444",
    "grpc_addr": ":7899",
    "tls_cert_file": "./fixtures/notary-signer.crt",
    "tls_key_file": "./fixtures/notary-signer.key",
    "client_ca_file": "./fixtures/notary-server.crt"
  }
}
Parameter Required Description
http_addr yes The TCP address (IP and port) to listen for HTTP traffic on. Examples:
  • ":4444" means listen on port 4444 on all IPs (and hence all interfaces, such as those listed when you run ifconfig)
  • "127.0.0.1:4444" means listen on port 4444 on localhost only. That means that the server is not accessible except locally (via SSH tunnel, or just on a local terminal)
grpc_addr yes The TCP address (IP and port) to listen for GRPC traffic. Examples:
  • ":7899" means listen on port 7899 on all IPs (and hence all interfaces, such as those listed when you run ifconfig)
  • "127.0.0.1:7899" means listen on port 7899 on localhost only. That means that the server is not accessible except locally (via SSH tunnel, or just on a local terminal)
tls_key_file yes The path to the private key to use for HTTPS. The path is relative to the directory of the configuration file.
tls_cert_file yes The path to the certificate to use for HTTPS. The path is relative to the directory of the configuration file.
client_ca_file no The root certificate to trust for mutual authentication. If provided, any clients connecting to Notary signer need a client certificate signed by this root. If not provided, mutual authentication is not required. The path is relative to the directory of the configuration file.

storage section (required)

This is used to store encrypted private keys. We only support MySQL or an in-memory store, currently.

Example:

"storage": {
  "backend": "mysql",
  "db_url": "user:pass@tcp(notarymysql:3306)/databasename?parseTime=true",
  "default_alias": "passwordalias1"
}
Parameter Required Description
backend yes Must be "mysql" or "memory". If "memory" is selected, the db_url is ignored.
db_url yes if not memory The the Data Source Name used to access the DB. (include parseTime=true as part of the DSN)
default_alias yes if not memory This parameter specifies the alias of the current password used to encrypt the private keys in the DB. All new private keys are encrypted using this password, which must also be provided as the environment variable NOTARY_SIGNER_<DEFAULT_ALIAS_VALUE>. See the environment variable section for more information.

Environment variables (required if using MySQL)

Notary signer stores the private keys in encrypted form. The alias of the passphrase used to encrypt the keys is also stored. In order to encrypt the keys for storage and decrypt the keys for signing, the passphrase must be passed in as an environment variable.

For example, the configuration above specifies the default password alias to be passwordalias1.

If this configuration is used, then you must:

export NOTARY_SIGNER_PASSWORDALIAS1=mypassword

so that that Notary signer knows to encrypt all keys with the passphrase mypassword, and to decrypt any private key stored with password alias passwordalias1 with the passphrase mypassword.

Older passwords may also be provided as environment variables.

Let’s say that you wanted to change the password that is used to create new keys (rotating the passphrase and re-encrypting all the private keys is not supported yet).

You could change the config to look like:

"storage": {
  "backend": "mysql",
  "db_url": "user:pass@tcp(notarymysql:3306)/databasename?parseTime=true",
  "default_alias": "passwordalias2"
}

Then you can set:

export NOTARY_SIGNER_PASSWORDALIAS1=mypassword
export NOTARY_SIGNER_PASSWORDALIAS2=mynewfancypassword

That way, all new keys are encrypted and decrypted using the passphrase mynewfancypassword, but old keys that were encrypted using the passphrase mypassword can still be decrypted.

The environment variables for the older passwords are optional, but Notary Signer cannot decrypt older keys if they are not provided, and attempts to sign data using those keys fail.

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