M/N upgrades - Update the upgrade documentation with any M/N gotchas

[Michele Baldessari]

I'd like to track all the gotchas we need to add in the docs for the M/N upgrade.

1) We need to add the ceilometer migration step (once it lands)

2) In case the operator uses ceph and the filesystem is ext4, the newton ceph versions (jewel) will complain about filename size limits and will refuse to start (this did not happen with the hammer/mitaka version):
User needs to set these on ext4:
parameter_defaults:
  ExtraConfig:
    ceph::profile::params::osd_max_object_name_len: 256
    ceph::profile::params::osd_max_object_namespace_len: 64

[Michele Baldessari (michele)]

3) When using Ceph we might be affected by:
https://bugs.launchpad.net/tripleo/+bug/1628632

We need a workaround for that as well

[Michele Baldessari (michele)]

3) So the workaround for gnocchi-statsd: it seems to be enough to inject python2-cradox in the image

[Michele Baldessari (michele)]

4) We need to either document a workaround or solve the bug https://bugs.launchpad.net/tripleo/+bug/1624727 - Could not fetch contents for file:///home/stack/tripleo-heat-templates/puppet/post.yaml
Right now the workaround I am using is to hope in the tht folder and run "swift download overcloud"

[Michele Baldessari (michele)]

5) We also need to make sure we note that new ceph repos are needed when moving to newton:

cat > ~/overcloud-repo.yaml <<EOF
parameter_defaults:
  UpgradeInitCommand: |
    set -e
    curl -L -o /etc/yum.repos.d/delorean-deps.repo http://trunk.rdoproject.org/centos7-newton/delorean-deps.repo
    curl -L -o /etc/yum.repos.d/delorean.repo http://trunk.rdoproject.org/centos7-newton/current-passed-ci/delorean.repo
    curl -L -o /etc/yum.repos.d/CentOS-Ceph-Jewel.repo https://raw.githubusercontent.com/CentOS-Storage-SIG/centos-release-ceph-jewel/master/CentOS-Ceph-Jewel.repo && sed -i -e 's%gpgcheck=.
*%gpgcheck=0%' /etc/yum.repos.d/CentOS-Ceph-Jewel.repo
    yum clean all
EOF

[Michele Baldessari (michele)]

6) We need to add IgnoreCephWarnings as param if there is only one ceph node

[Michele Baldessari (michele)]

7) Document ceilometer upgrade step before init
8) Document aodh migration after convergence

[Michele Baldessari (michele)]

9) Add sahara steps (keep it or not, etc.)

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/384717

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/384717
Committed: https://git.openstack.org/cgit/openstack/tripleo-docs/commit/?id=6b566c285b660d500fcb71f33f29e17f9ddc3419
Submitter: Jenkins
Branch: master

commit 6b566c285b660d500fcb71f33f29e17f9ddc3419
Author: Michele Baldessari <email address hidden>
Date: Mon Oct 10 23:12:28 2016 +0200

    Update upgrade instructions for M->N upgrades

    Update the documentations with the additional steps needed
    for an M->N upgrades.

     * Document ceilometer wsgi pre upgrade step
     * Document aodh data migration post converge step

    We should address the following in a later commit:
    - Some more details upstream about ceph jewel repos
    - IgnoreCephWarnings notice when using only one ceph node

    Closes-Bug: #1628551
    Co-Authored-By: Marios Andreou <email address hidden>
    Change-Id: I8ebf5a4e05271666de6f4044a2781b503649333f