After upgrading to 5.6 - using the Gitlab Mattermost installer on Ubuntu 16.04 - we’ve been unable to invite new users.
They are first taken to a normal looking page, with a button labelled “GitLab Single Sign-on”. This button links to:
http://mattermost.mysite.com/oauth/gitlab/signup?d={%22display_name%22%3A%22R+Kal%C3%B8%22%2C%22email%22%3A%22mail%40gmail.com%22%2C%22name%22%3A%22group%22}&t=a4zbfwfjwtip4gukqryz9zsp8ao6bpwoj6894zss9tym5yqaq5e9w5ug9pcbb6nf
curl "http://mattermost.mysite.com/oauth/gitlab/signup?d={"%"22display_name"%"22"%"3A"%"22R+Kal"%"C3"%"B8"%"22"%"2C"%"22email"%"22"%"3A"%"22mail"%"40gmail.com"%"22"%"2C"%"22name"%"22"%"3A"%"22group"%"22}&t=a4zbfwfjwtip4gukqryz9zsp8ao6bpwoj6894zss9tym5yqaq5e9w5ug9pcbb6nf" -H "User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:65.0) Gecko/20100101 Firefox/65.0" -H "Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8" -H "Accept-Language: en-US,en;q=0.5" --compressed -H "Connection: keep-alive" -H "Cookie: ajs_user_id="%"22s5fhdx65mfggde184uhd4zqima"%"22; ajs_group_id=null; ajs_anonymous_id="%"2200000000000000000000000000"%"22" -H "Upgrade-Insecure-Requests: 1"
<!DOCTYPE html><html><head></head>
<body onload="window.location = '/error?message=The+signup+link+does+not+appear+to+be+valid&s=MEUCIGWdlYOZdClVDJ02bi6BVm8CBLItuwJypk_MRD67lG18AiEA_g7EVrUy_lJ5tzMI5AGCmRGroKL0isGsg2SbgyRCkLM='">
<noscript><meta http-equiv="refresh" content="0; url=/error?message=The+signup+link+does+not+appear+to+be+valid&s=MEUCIGWdlYOZdClVDJ02bi6BVm8CBLItuwJypk_MRD67lG18AiEA_g7EVrUy_lJ5tzMI5AGCmRGroKL0isGsg2SbgyRCkLM="></noscript>
<a href="/error?message=The+signup+link+does+not+appear+to+be+valid&s=MEUCIGWdlYOZdClVDJ02bi6BVm8CBLItuwJypk_MRD67lG18AiEA_g7EVrUy_lJ5tzMI5AGCmRGroKL0isGsg2SbgyRCkLM=" style="color: #c0c0c0;">...</a>
</body></html>
From the mattermost.log:
{"level":"error","ts":1553072509.95022,"caller":"web/context.go:60","msg":"The signup link does not appear to be valid","path":"/oauth/gitlab/signup","request_id":"xye65ygdw3fwpj9xd7eo16x6br","ip_addr":"****","user_id":"","method":"GET","err_where":"GetTeamIdFromQuery","http_code":400,"err_details":""}
I’m new to Mattermost, so any explanations or suggestions of what might be going on is much appreciated.