Iss2509 - Store KeyStore credentials in the CREDS, provide to HTTP/Docker Manager

[jadecarino]

Why?

Refer to galasa-dev/projectmanagement#2509

This pull request adds the ability to store a KeyStore credential in the local and ETCD CREDS stores. The purpose of this is to be able to provide that credential to the HTTP Manager so it can use it to set up client authentication with the enclosed certificates. The HTTP Manager can then pass this to the Docker Manager, so it can contact protected Docker engines via HTTPS.

Changes

Framework/Credentials

• Adds a new credential type able to be stored in the credentials stores and used by Galasa tests, CredentialsKeyStore, which represents a Java KeyStore.
• The CredentialsKeyStore has three parts: the KeyStore data which should be formatted as a prefix of "base64:" followed by the bytes of a Java KeyStore base64-encoded, the KeyStore password, and the KeyStore type (PKCS12 or JKS).
• Unit tests for CredentialsKeyStore class.

Managers

• New CPS property for the Docker Manager to provide a credentials ID for a particular Docker engine. If provided, the Docker Manager will attempt to retrieve the CredentialsKeyStore from the credentials.properties, and configure an HTTPS connection with the included certificates.
• Changes to the HTTP Manager to set up client authentication using this KeyStore's certificates.
• Changes to DockerExecImpl as this uses a raw HttpConnection instead of the manager's HTTPClient, and so couldn't access the KeyStore certificates, so this change checks if an SSL Context is available, and if so uses it in the HttpConnection.
• DockerManagerIVT has been successfully ran against a protected Docker engine to test these changes.

REST API

• KeyStore credentials can be stored and retrieved in the ETCD CREDS store by REST API calls.
• Unit tests for servlet calls to create/update KeyStore credentials.
• REST API changes tested in Minikube system.

Documentation

• User facing documentation.
• Release notes.

[eamansour]

Overall looks good! I've added a few thoughts and suggestions to the PR - happy to approve once they're addressed!