Enabling Instance Identity
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This topic describes enabling the Instance Identity system for your Cloud Foundry Application Runtime (CFAR) deployment. The Instance Identity system provides each app instance with a unique PEM-encoded X.509 certificate and PKCS#1 RSA private key pair that encodes its identity in the CFAR deployment.
Instance Identity is enabled by default in cf-deployment.
To enable this feature in CFAR deployments not based on cf-deployment, generate a PEM-encoded CA certificate and private key for the Diego Cell reps to use to issue certificates with the characteristics listed below in Requirements. Next, set the following properties in the BOSH deployment manifest on the
rep job on the Diego Cells:
diego.executor.instance_identity_ca_cert: PEM-encoded CA certificate used to issue Instance Identity credentials
diego.executor.instance_identity_key: PEM-encoded private key used to issue instance identity credentials
Operators may also wish to install the Instance Identity CA certificate as a trusted system certificate for apps, so that app instances trust each others’ Instance Identity credentials automatically. For more information about installing this CA certificate, see Configuring Trusted System Certificates for Apps.
For information about how developers can use the Instance Identity credentials in apps on CFAR, see Using Instance Identity Credentials.
By default, the certificate is valid for 24 hours after the container is created. The CFAR operator can control this validity period by modifying the
diego.executor.instance_identity_validity_period_in_hours BOSH property in the
rep job. The smallest allowed validity duration is 1 hour.
The Diego Cell rep supplies a new certificate and private key pair to the app instance before the end of the validity period. The new pair of files replaces the existing pair at the same path locations, with each file replaced atomically.
If the validity period exceeds 4 hours, the pair regenerates between 1 hour and 20 minutes before the end of the validity period.
If the validity period is less than or equal to 4 hours, the pair regenerates between ¼ and 1/12 of the time to the end of the period.
The CA certificate that the Diego Cell rep uses to issue Instance Identity credentials must have all the properties required to sign other certificates:
Subject Key Identifiermust be set.
If the Diego Cell rep is configured with an intermediate CA certificate, the certificate should have either an empty
ExtendedKeyUsageextension or one with the