Import Project from Github is not working with "Integration of GitLab instance with GitHub"

Summary

Getting a redirect_uri_mismatch when trying to import a project from Github. The user is redirected to the homepage after clicking on Github icon. Error from console is below. This is with following the steps that are found on Integration with Github - https://docs.gitlab.com/ee/integration/github.html

error: redirect_uri_mismatch
error_description: The redirect_uri MUST match the registered callback URL for this application.
error_uri: https://developer.github.com/apps/managing-oauth-apps/troubleshooting-authorization-request-errors/#redirect-uri-mismatch

However login via github works.

Steps to reproduce

This is issue is present under both Docker Gitlab Instance and via Omnibus package installation.

Clean installation of Gitlab with HTTPS external_url. Create Github OAuth App on Github (with HTTPS urls for Homepage URL and Authorization callback URL) Connect (associate) Github to Gitlab account under user's Gitlab account. Login via Github into Gitlab account Try to import new project and select Github

What is the current bug behavior?

User is redirected to Dashboard. Browser console error refers to redirect_uri_mismatch. Please note that login via Github works.

What is the expected correct behavior?

To see a list of github repos to import

Relevant logs and/or screenshots

error: redirect_uri_mismatch
error_description: The redirect_uri MUST match the registered callback URL for this application.
error_uri: https://developer.github.com/apps/managing-oauth-apps/troubleshooting-authorization-request-errors/#redirect-uri-mismatch

Output of checks

This bug happens on self-hosted version of Gitlab.

Results of GitLab environment info

Expand for output related to GitLab environment info 
System information
System:         Ubuntu 18.04
Proxy:          no
Current User:   git
Using RVM:      no
Ruby Version:   2.5.3p105
Gem Version:    2.7.9
Bundler Version:1.17.3
Rake Version:   12.3.2
Redis Version:  3.2.12
Git Version:    2.21.0
Sidekiq Version:5.2.7
Go Version:     unknown

GitLab information
Version:        11.11.0-ee
Revision:       deb6f84e91f
Directory:      /opt/gitlab/embedded/service/gitlab-rails
DB Adapter:     PostgreSQL
DB Version:     9.6.11
URL:            https://gitlabd.somyx.com
HTTP Clone URL: https://gitlabd.somyx.com/some-group/some-project.git
SSH Clone URL:  git@gitlabd.somyx.com:some-group/some-project.git
Elasticsearch:  no
Geo:            no
Using LDAP:     no
Using Omniauth: yes
Omniauth Providers: github


GitLab Shell
Version:        9.1.0
Repository storage paths:
  • default: /var/opt/gitlab/git-data/repositories GitLab Shell path: /opt/gitlab/embedded/service/gitlab-shell Git: /opt/gitlab/embedded/bin/git

Results of GitLab application Check

Expand for output related to the GitLab application check 
Checking GitLab subtasks ...


Checking GitLab Shell ...


GitLab Shell: ... GitLab Shell version >= 9.1.0 ? ... OK (9.1.0)
Running /opt/gitlab/embedded/service/gitlab-shell/bin/check
Check GitLab API access: OK
Redis available via internal API: OK


Access to /var/opt/gitlab/.ssh/authorized_keys: OK
gitlab-shell self-check successful


Checking GitLab Shell ... Finished


Checking Gitaly ...


Gitaly: ... default ... OK


Checking Gitaly ... Finished


Checking Sidekiq ...


Sidekiq: ... Running? ... yes
Number of Sidekiq processes ... 1


Checking Sidekiq ... Finished


Checking Incoming Email ...


Incoming Email: ... Reply by email is disabled in config/gitlab.yml


Checking Incoming Email ... Finished


Checking LDAP ...


LDAP: ... LDAP is disabled in config/gitlab.yml


Checking LDAP ... Finished


Checking GitLab App ...


Git configured correctly? ... yes
Database config exists? ... yes
All migrations up? ... yes
Database contains orphaned GroupMembers? ... no
GitLab config exists? ... yes
GitLab config up to date? ... yes
Log directory writable? ... yes
Tmp directory writable? ... yes
Uploads directory exists? ... yes
Uploads directory has correct permissions? ... yes
Uploads directory tmp has correct permissions? ... skipped (no tmp uploads folder yet)
Init script exists? ... skipped (omnibus-gitlab has no init script)
Init script up-to-date? ... skipped (omnibus-gitlab has no init script)
Projects have namespace: ... can't check, you have no projects
Redis version >= 2.8.0? ... yes
Ruby version >= 2.5.3 ? ... yes (2.5.3)
Git version >= 2.21.0 ? ... yes (2.21.0)
Git user has default SSH configuration? ... yes
Active users: ... 1
Elasticsearch version 5.6 - 6.x? ... skipped (elasticsearch is disabled)


Checking GitLab App ... Finished


Checking GitLab subtasks ... Finished
Edited by 🤖 GitLab Bot 🤖