spring-cloud-vault | Configuration Integration with HashiCorp Vault | Identity Management library

As pointed put by Nicoll, With Spring Cloud Vault 3.0 and Spring Boot 2.4, the bootstrap context initialization (bootstrap.yml, bootstrap.properties) of property sources was deprecated. This can be fixed in one of the 2 ways

1. Use Spring Boot 2.4.0 Config Data API to import configuration from Vault
2. Enable the bootstrap context either by setting the configuration property spring.cloud.bootstrap.enabled=true or by including the dependency org.springframework.cloud:spring-cloud-starter-bootstrap

1. Use Spring Boot 2.4.0 Config Data API

Move bootstrap.yml configuration to application.yml and define spring.config.import to import all profiles. And it looks like below

When you get an error about could not resolve dependencies in gradle, then there are several things you need to check.

1. Proxy settings (should be inside gradle.properties)
2. Permission for creating directories (particularly in %GRADLE_HOME%\caches\modules-2\files-2.1)

For the problem of proxy setting, simply set values for the following fields inside gradle.properties

You are missing the annotations on DatabaseConfig.java

Which will be something like this.

I fixed this issue after updating my vault policy with the below configuration:

The root cause of the problem can be found form this error message:

It was the policy setting. I updated it to below and it worked! Specific path instead of *.

The expiry threshold controls the renewal time at which the lease is renewed.

For example: it seems pretty clear to me that if the lease TTL is 10 minutes, and if the expiry-threshold is set to 1 minute, then 9 minutes after the lease is acquired spring-cloud-vault would renew the lease.

Your understanding is correct.

What's about min-renewal?

When the remaining validity time of your lease is less than 1 minute (say 30 seconds), then the calculated renewal time would be 30 seconds in the past (or now, as we cannot schedule things to happen in the past). min-renewal helps to debounce renewal requests. This is because, in such a scenario, refresh happens immediately.

Once renewed, SecretLeaseContainer schedules a subsequent renewal that reports a lease validity of slightly less than 30 seconds. We don't want to create a loop that hammers your Vault server with renewal requests if the remaining lease duration is less than expiry-threshold.

Example:

• expiry-threshold: 60 seconds
• min-renewal: 10 seconds

The following list of events shows with a time correlation what happens at which time assuming the TTL is final and cannot be extended:

• 10:00:00 Lease obtained. TTL 10 minutes (600 seconds). Schedule lease renewal in 9 minutes (10 minutes TTL - 1 minute expiry threshold -> 9 minutes)
• 10:09:00 Lease renewed. Remaining TTL 1 minute (60 seconds). Schedule lease renewal in 10 seconds (1 minute TTL - 1 minute expiry threshold -> 0 minutes. Fall back to 10 seconds min-renewal as that is the larger value -> 10 seconds).
• 10:09:10 Lease renewed. Remaining TTL 50 seconds. Schedule lease renewal in 10 seconds (50 seconds TTL - 1 minute expiry threshold -> -10 seconds. Fall back to 10 seconds min-renewal as that is the larger value -> 10 seconds).
• (continue until reaching 10 seconds)
• 10:09:50 Lease renewed. Remaining TTL less than 10 seconds. Min-renewal is greater than the remaining TTL and the lease is considered expired.

Example where expiry threshold is greater than min-renewal:

• expiry-threshold: 5 minutes (180 seconds)
• min-renewal: 6 minutes (360 seconds)

The following list of events shows with a time correlation what happens at which time assuming the TTL is final and cannot be extended:

• 10:00:00 Lease obtained. TTL 10 minutes (600 seconds). Schedule lease renewal in 6 minutes (10 minutes TTL - 5 minute expiry threshold -> 5 minutes. Min-renewal is set to 6 minutes to issue a renewal at most once in 6 minutes -> 6 minutes)

• 10:06:00 Lease obtained. TTL 4 minutes (360 seconds). Schedule lease renewal in 6 minutes (4 minutes TTL - 5 minute expiry threshold -> -1 minutes. 6 minutes min-renewal as that is the is greater than the remaining TTL so the lease is considered expired)