invalid authBackend: parse ( first path segment in URL cannot contain colon )

Summary

gitlab-workhorse does not run due to an error in the parsing of auth_backend.

run: gitaly: (pid 4604) 1034s; run: log: (pid 1606) 1473s
run: gitlab-monitor: (pid 4610) 1033s; run: log: (pid 1616) 1473s
down: gitlab-workhorse: 0s, normally up, want up; run: log: (pid 1638) 1472s
run: logrotate: (pid 4631) 1032s; run: log: (pid 1676) 1471s
run: mailroom: (pid 4712) 1025s; run: log: (pid 1612) 1473s
run: node-exporter: (pid 4715) 1025s; run: log: (pid 1614) 1473s
run: postgres-exporter: (pid 4722) 1025s; run: log: (pid 1622) 1473s
run: postgresql: (pid 4743) 1024s; run: log: (pid 1610) 1473s
run: prometheus: (pid 4747) 1024s; run: log: (pid 1613) 1473s
run: redis: (pid 4770) 1023s; run: log: (pid 1617) 1473s
run: redis-exporter: (pid 4783) 1023s; run: log: (pid 1605) 1473s
run: sidekiq: (pid 4820) 1021s; run: log: (pid 1615) 1473s
run: unicorn: (pid 4850) 1020s; run: log: (pid 1620) 1473s

Probably the most relevant error message:

==> /var/log/gitlab/gitlab-workhorse/current <==
2017-06-09_18:48:06.54135 2017/06/09 20:48:06 invalid authBackend: parse 127.0.0.1:8081: first path segment in URL cannot contain colon

Adding http://:

==> /var/log/gitlab/gitlab-workhorse/current <==
2017-06-09_18:45:43.16344 2017/06/09 20:45:43 Starting gitlab-workhorse v2.0.0-20170607.215504
2017-06-09_18:45:43.16348 2017/06/09 20:45:43 listen tcp: address http://127.0.0.1:8081: too many colons in address

The issue started to appear after upgrading from 9.1.3-ce.0 to 9.2.5-ce.0 (Ubuntu 16.04).

Results of GitLab environment info

Expand for output related to GitLab environment info

System information System: Ubuntu 16.04 Current User: git Using RVM: no Ruby Version: 2.3.3p222 Gem Version: 2.6.6 Bundler Version:1.13.7 Rake Version: 10.5.0 Redis Version: 3.2.5 Git Version: 2.11.1 Sidekiq Version:5.0.0

GitLab information Version: 9.2.5 Revision: 6f2e590 Directory: /opt/gitlab/embedded/service/gitlab-rails DB Adapter: postgresql URL: - HTTP Clone URL: - SSH Clone URL: - Using LDAP: no Using Omniauth: no

GitLab Shell Version: 5.0.4 Repository storage paths:

default: /var/opt/gitlab/git-data/repositories Hooks: /opt/gitlab/embedded/service/gitlab-shell/hooks Git: /opt/gitlab/embedded/bin/git

Possible fixes

https://github.com/golang/go/issues/19297 seems related.

Unfortunately, the suggested workaround //127.0.0.1:8081 does not work either:

==> /var/log/gitlab/gitlab-workhorse/current <==
2017-06-09_19:03:38.73850 2017/06/09 21:03:38 invalid authBackend: invalid scheme, only 'http' is allowed: "//127.0.0.1:8081"

Things used to work fine using 127.0.0.1:8081 prior to the last upgrade. Am I missing something?