for upgrades bootstrap_url port in group_vars/all/dcos.yml needs to be 8080

[Boes-man]

fatal: [18.236.126.226]: FAILED! => {"changed": false, "dest": "/tmp/dcos/1.12.3/upgrade_from_1.12.2/", "gid": 0, "group": "root", "mode": "0755", "msg": "Request failed", "owner": "root", "response": "HTTP Error 404: Not Found", "secontext": "unconfined_u:object_r:user_tmp_t:s0", "size": 6, "state": "directory", "status_code": 404, "uid": 0, "url": "http://172.12.0.131:80/1.12.3/genconf/serve/upgrade_from_1.12.2/latest/dcos_node_upgrade.sh"}

I setup dcos.yml based on current cluster bootstrap url, i.e. port 80 The upgrade flow is hard coded for boostrap url port 8080

Updating group_vars/all/dcos.yaml bootstrap_url: http://172.12.0.131:8080 allows download to complete.