Respect `mod_unique_id` and refactor `OC_Request::getRequestId`

When `mod_unique_id` is enabled the ID generated by it will be used for logging. This allows for correlation of the Apache logs and the ownCloud logs.

Testplan:

- [ ] When `mod_unique_id` is enabled the request ID equals the one generated by `mod_unique_id`.
- [ ] When `mod_unique_id` is not available the request ID is a 20 character long random string
- [ ] The generated Id is stable over the lifespan of one request

Changeset looks a little bit larger since I had to adjust every unit test using the HTTP\Request class for proper DI.

Fixes https://github.com/owncloud/core/issues/13366

1 files changed, 7 insertions, 0 deletions

diff --git a/lib/public/irequest.php b/lib/public/irequest.php
index 988b3aebd7b..b5ea1fa95da 100644
--- a/lib/public/irequest.php
+++ b/lib/public/irequest.php
@@ -127,4 +127,11 @@ interface IRequest {
 	 * @return bool true if CSRF check passed
 	 */
 	public function passesCSRFCheck();
+
+	/**
+	 * Returns an ID for the request, value is not guaranteed to be unique and is mostly meant for logging
+	 * If `mod_unique_id` is installed this value will be taken.
+	 * @return string
+	 */
+	public function getId();
 }