(see bug 1508383 for docker-worker equivalent) Take a root URL as configuration, required Pass root URL to taskcluster-proxy pass TASKCLUSTER_PROXY_URL and TASKCLUSTER_ROOT_URL to tasks

Note that this is also a good time to address bug 1508383 comment 2 in generic-worker.

Looking at this now...

Commits pushed to master at https://github.com/taskcluster/generic-worker https://github.com/taskcluster/generic-worker/commit/0ff6a4c4dfa8f37bf3892509471edaa16a514574 Bug 1516458 - pass an explicit list of scopes to the proxy This has a few advantages: * permits adding the queue:create-artifact:.. scope * avoides an unnecessary additional call to queue.task(..) by the proxy * duplicates docker-worker's approach to minimize chance of behavior change https://github.com/taskcluster/generic-worker/commit/309d2f54621c44ea5fa5244015b844ddfebe77ef Bug 1516458 - require rootUrl in worker configuration https://github.com/taskcluster/generic-worker/commit/8a28fab55db23ea8b49ef7e95a40934ec0ad0e3d Bug 1516458 - set TASKCLUSTER_ROOT_URL in tasks https://github.com/taskcluster/generic-worker/commit/4b043b1031d715d4a35226601eaf8666c7296781 Bug 1516458 - improve handling of env vars * factor out and test non-platform-specific MergeEnvLists * handle the task-user and current-user modes differently https://github.com/taskcluster/generic-worker/commit/4c39491851ba550461900e57ff5ac3d9e1c7adb9 Bug 1516458 - pass --root-url to tc-proxy and set TASKCLUSTER_PROXY_URL With this change, the proxy knows the rootUrl, and the task has a reliable indication of the proxy URL There is no provision for a feature to set a task environment variable, and in fact features are not even initialized yet when the task commands are created, so this special-cases the TaskclusterProxyFeature for inclusion in the task environment. https://github.com/taskcluster/generic-worker/commit/c9b74f54a711e9bb6206b03c398a70e20e0a5574 Bug 1516458 - document new rootUrl and proxy behavior https://github.com/taskcluster/generic-worker/commit/7f4f1b133d1c64a2271e17d0ab48593f7dcc1503 Bug 1516458 - supply TASKCLUSTER_ROOT_URL in CI https://github.com/taskcluster/generic-worker/commit/38297d134f76fe415092966b6bf5594097f52eff Bug 1516458 - swap tabs for spaces in usage text and provide example rootURL https://github.com/taskcluster/generic-worker/commit/b8cc67ac56495199b6772609df0ad92ab3215d22 Bug 1516458 - code beautification - fix alphabetical ordering of property names in bulk property activities https://github.com/taskcluster/generic-worker/commit/01bde78eaa6b4ea9423b717de25053899b856fe5 Merge pull request #135 from djmitche/bug1516458 Bug 1516458 - take rootURL as config and set TASKCLUSTER_ROOT_URL and TASKCLUSTER_PROXY_URL