NPA-6981: Create health check endpoint within VRS

[davesmallnhs]

Pull Request

🧾 Ticket Link

https://nhsd-jira.digital.nhs.uk/browse/NPA-6981

📄 Description/Summary of Changes

• This change to the SPEC codebase changes the behaviour of the Apigee healthcheck endpoint GET /_status
• Currently, a call to GET https://internal-dev.api.service.nhs.uk/validated-relationships/_status results in a check against http://mocktarget.apigee.net - and we have been asked to stop using this mock endpoint
• With this change, a call to GET https://internal-dev.api.service.nhs.uk/validated-relationships/_status (and higher infras, once deployed) will redirect these requests to the _status endpoint in the VRS API itself.
• When initially deployed, this will fail, but https://github.com/NHSDigital/proxy-validated-relationships-service/pull/1550 will deploy a Lambda to handle these requests.

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🧪 Developer Testing Carried Out

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📋 PR Principles

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🏷️ Naming Conventions Reminder

Please ensure the following naming conventions are followed:

• PR title follows the format: NPA-XXXX: <short-description>
• Branch name follows the convention: <type>/NPA-XXXX/<short-description>
• Commit messages follow the template: NPA-XXXX: <short-description>

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[Copilot]

Pull request overview

This PR is a proof-of-concept change to the Apigee proxy configuration intended to demonstrate that updating configuration affects the healthcheck behavior.

Changes:

• Updated the live Apigee ServiceCallout.CallHealthcheckEndpoint policy to call a different healthcheck URL.

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[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981

[github-actions]

This branch is work on a ticket in the NHS Digital NPA JIRA Project. Here's a handy link to the ticket:

NPA-6981