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On Tue, Jul 07, 2015, Paul Michali <pc at michali.net> wrote:
> Thanks Salvatore for the responses. See @PCM in-line...
>
>
>
> On Tue, Jul 7, 2015 at 6:14 AM Salvatore Orlando <sorlando at nicira.com
> <mailto:sorlando at nicira.com>> wrote:
>
>     Some comments inline.
>
>     Salvatore
>
>     On 6 July 2015 at 20:00, Paul Michali <pc at michali.net
>     <mailto:pc at michali.net>> wrote:
>
>         Hi,
>
>         I have some urgent requests about migration that I'm hoping to get
>         some info on. I'm working on a bug where I need to add two (related)
>         fields to a table for VPNaaS. Here's the objectives related to
>         migration...
>
>         1) create local_v4_ip and lcoal_v6_ip fields in the vpnservice table
>         2) for each entry in the vpnservice table:
>             2.1) Get the router.gw_port.fixed_ips list
>             2.2) Determine the version of each fixed IP and store the first
>         of each version (if any) into the appropriate new field.
>
>         I have created a migration file, and I changed the down_revision to
>         be the number of the revision that is the first in the migration
>         chain in the VPN repo.
>
>         Here are the many questions I have...
>
>         When I look in the VPN repo, the HEAD file has the version 'kilo',
>         which is not the current head. 
>
>
>         Shouldn't it the version number of the first file in the migration chain?
>
>
>     It should indeed. How are you generating the revision script? Using
>     neutron-db-manage it should be updated automatically [1]
>
>
> @PCM I ran neutron-db-manage, when in the neutron repo, and it assigned some
> version, but it was not the latest in the neutron-vpnaas repo.
neutron-db-manage does not handle alembic branches in separate repos very well
at all yet. I am working on updating it with
https://review.openstack.org/198524 but I have quite a lot left to do.

>
> I checked the VPN repo and there were a chain of versions, which I used to
> determine what the head should be and have set the version accordingly.
> However, in the current repo, head is set to "kilo", which appears to be
> incorrect.  The versions are:
>
> 56893333aa52
> kilo   <<< HEAD
> 3ea02b2a773e
> start_neutron_vpnaas
> None
Ouch. That is an error, because https://review.openstack.org/190569 should have
updated HEAD but didn't.

The version sequence (you can see it in any devstack run) is:

INFO  [alembic.migration] Running upgrade  -> start_neutron_vpnaas, start
neutron-vpnaas chain
INFO  [alembic.migration] Running upgrade start_neutron_vpnaas -> 3ea02b2a773e,
add_index_tenant_id
INFO  [alembic.migration] Running upgrade 3ea02b2a773e -> kilo, kilo
INFO  [alembic.migration] Running upgrade kilo -> 56893333aa52, fix identifier
map fk

>
> Should I do a separate commit that fixes the HEAD file, or just fix it as
> part of the bug fix I'm working on.
Yes, you should immediately submit a patch to change HEAD to 56893333aa52.

>
> BTW, at one point, after having correctly set the HEAD and versions in my new
> migration file, I think I ran neutron-db-manage check_migration, and I think
> it set the HEAD to my version, but it did that in the neutron repo, and not
> the VPN repo.  I might have been running from the wrong repo?
I working on updating the devref docs for this process. Things have changed
quite a bit with the alembic branches in separate repos.

>
>
>
>         For my commit, I'm assuming I change the HEAD file to use my
>         migration file's version?
>
>
>     You can do that manually too, yes.
>      
>
>
>         I set HEAD to my migration file, and my file has a down revision of
>         the previous head's revision. If I run 'neutron-db-manage
>         --config-file ../neutron/etc/neutron.conf --config-file
>         ../neutron/etc/neutron/plugins/ml2/ml2_conf.ini check_migration'
>         there is no output so I guess that is OK.
>
>         As I develop my new migration file, is there a way that I can test it
>         (running neutron-db-migration, maybe)?
>
>
>     When I test migrations I usually dump the database, run the migration
>     with neutron-db-manage upgrade HEAD (I think it's not necessary to
>     specify HEAD), and restore the db from the dump if the migration fails.
>      
>
>         Is there a way to run the migration file under the debugger, as well
>         (importing pdb, for example)?
>
>
>     The migration process is just like any python application, so I guess you
>     can debug it with pdb. 
>
>
> @PCM Ah, so use "neutron-db-manage upgrade HEAD". That was the piece that was
> missing. I take it there are no specific unit tests of the migration files?
>
>
>      
>
>
>         In the migration, I can add the columns needed. What's the best way
>         to fill out those fields - using raw SQL queries or create a Session
>         object and access the VpnService object's router object?
>
>
>     If the default value for the column is not enough, and you need to
>     specify a value which depends on other values in the same row I would
>     prefer plain SQL statements, but if that become cumbersome I guess it's
>     ok to use sqlalchemy's session.
>
>
>         I see there is some op.bind() call and then engine.execute(), but
>         could use some help on the best way to extract the needed queries (I
>         need to access the vpnservice's router, and then access the (Port)
>         gw_port relationship, and from that access the (IPAllocation)
>         fixed_ips list).
>
>
>     Perhaps you can point us to the review pages on gerrit, and we can
>     provide detailed comments there.
>
>
> @PCM Yeah, I haven't pushed it up yet. I have a few more changes to make, and
> should be able to get it up in a few days. The LP bug is 1464387.
>
> Essentially, in the vpnservices table, I'm adding an IPv4 and/or IPv6
> addresses for the  "local" end of VPN connections that will be established.
> This is to allow alternative VPN implementation (appliances, separate S/W,
> H/W, VM based VPN, etc) to specify addresses different than what is available
> on the Neutron router.
>
> However, for the reference implementation, we'll use the Neutron router's
> fixed_ips list (as is done today), and to handle the migration, I'm thinking
> the following is needed:
>
> 1) create the new columns.
> 2) Identify the router for that service and obtain it's GW fixed_ips list.
> 3) Pick first IPv4 address (if any) and IPv6 address (if any), and store in
> new columns.
>
> So I need to form a query and code to do this.
>
>
>      
>
>
>         Appreciate any advise here on how to debug the migration stuff...
>
>         Paul Michali (pc_m)
>
>
>     [1]
>     http://git.openstack.org/cgit/openstack/neutron/tree/neutron/db/migration/cli.py#n124 
>
>
>

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