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Secrets Management

A secret is any sensitive piece of information required for API gateway operations. Secrets may be part of the core Kong Gateway configuration, they may be used in plugins, or they might be part of configuration associated with APIs serviced by the gateway.

Some of the most common types of secrets used by Kong Gateway include:

Data store usernames and passwords, used with PostgreSQL and Redis
Private X.509 certificates
API keys
Sensitive plugin configuration fields, generally used for authentication, hashing, signing, or encryption.

Kong Gateway lets you store certain values in a vault. By storing sensitive values as secrets, you ensure that they are not visible in plaintext throughout the platform, in places such as kong.conf, in declarative configuration files, logs, or in the Kong Manager UI. Instead, you can reference each secret with a vault reference.

For example, the following reference resolves to the environment variable MY_SECRET_POSTGRES_PASSWORD:

{vault://env/my-secret-postgres-password}

In this way, secrets management becomes centralized.

Referenceable values

A secret reference points to a string value. No other data types are currently supported.

The vault backend may store multiple related secrets inside an object, but the reference should always point to a key that resolves to a string value. For example, the following reference:

{vault://hcv/pg/username}

Would point to a secret object called pg inside a HashiCorp Vault, which may return the following value:

{
  "username": "john",
  "password": "doe"
}

Kong receives the payload and extracts the "username" value of "john" for the secret reference of {vault://hcv/pg/username}.

If you have a single value secret with identifier pg/username, you need to add / as a suffix to a reference so that it is properly sent to the vault API:

{vault://hcv/pg/username/}

What can be stored as a secret?

Most of the Kong configuration values can be stored as a secret, such as pg_user and pg_password.

You can even store the default certificates in vaults, e.g.:

SSL_CERT=$(cat cluster.crt) \
SSL_CERT_KEY=$(cat cluster.key) \
KONG_SSL_CERT={vault://env/ssl-cert} \
KONG_SSL_CERT_KEY={vault://env/ssl-cert-key} \
kong prepare

The Kong license, usually configured with a KONG_LICENSE_DATA environment variable, can be stored as a secret.

The Kong Admin API certificate object can be stored as a secret.

Referenceable plugin fields

Some plugins have fields that can be stored as secrets in a vault backend. These fields are labelled as referenceable.

The following plugins support vault references for specific fields. See each plugin’s documentation for more information on each field:

Plugin	Referenceable fields
ACME	`config.account_email` `config.eab_kid` `config.eab_hmac_key` `config.storage_config.redis.auth` `config.storage_config.consul.token` `config.storage_config.vault.token`
AWS Lambda	`config.aws_key` `config.aws_secret` `config.aws_assume_role_arn`
Azure Functions	`config.apikey` `config.clientid`
Forward Proxy Advanced	`config.auth_username` `config.auth_password`
GraphQL Rate Limiting Advanced	`config.redis.username` `config.redis.password` `config.redis.sentinel_username` `config.redis.sentinel_password`
Kafka Log	`config.authentication.user` `config.authentication.password`
Kafka Upstream	`config.authentication.user` `config.authentication.password`
LDAP Authentication Advanced	`config.ldap_password` `config.bind_dn`
Loggly	`config.key`
OpenID Connect	`config.client_id` `config.client_secret` `config.client_jwk.k` `config.client_jwk.d` `config.client_jwk.p` `config.client_jwk.q` `config.client_jwk.dp` `config.client_jwk.dq` `config.client_jwk.qi` `config.client_jwk.oth` `config.client_jwk.r` `config.client_jwk.t` `config.session_secret` `config.session_redis_username` `config.session_redis_password`
OpenTelemetry	`config.headers`
Proxy Caching Advanced	`config.redis.username` `config.redis.password` `config.redis.sentinel_username` `config.redis.sentinel_password`
Rate Limiting	`config.redis_password` `config.redis_username`
Rate Limiting Advanced	`config.redis.username` `config.redis.password` `config.redis.sentinel_username` `config.redis.sentinel_password`
Request Transformer Advanced	`config.rename.body` `config.rename.headers` `config.rename.querystring` `config.replace.body` `config.replace.headers` `config.replace.querystring` `config.add.body` `config.add.headers` `config.add.querystring` `config.append.body` `config.append.headers` `config.append.querystring`
Response Rate Limiting	`config.redis_password` `config.redis_username`
SAML	`config.idp_certificate` `config.response_encryption_key` `config.request_signing_key` `config.request_signing_certificate` `config.session_secret` `config.session_redis_username` `config.session_redis_password`
Session	`config.secret`

Note: The Vault plugin interacts with the vaults and vault_credentials entities. For these entities, the vaults.vault_token and vault_credentials.secret_token parameters are referenceable.

Supported backends

Kong Gateway supports the following vault backends:

Environment variables
AWS Secrets Manager
GCP Secrets Manager
Azure Key Vaults
HashiCorp Vault

See the backends overview for more information about each option.

Get started

For further information on secrets management, see the following topics: