Advogato blog for skvidal

documenting for posterity – ansible – wait for a dir to exist before continuing

Thu, 23 May 2013 21:12:15 GMT

Got a ridiculous process **cough**Jenkins**Cough** that you have to wait to create a dir before doing things?

This might help you as godawful ugly as it is.

– name: wait for a dir to exist – this is just ugly
shell: while `true`; do [ -d /var/lib/jenkins/plugins/openid/WEB-INF/lib/ ] && break; sleep 5; done
async: 1800
poll: 20

sorting srpms by buildorder

Fri, 17 May 2013 19:10:33 GMT

Hey folks,
Working on something for Spot I revived some code I had written a
few years ago and then discovered that other people had made much more
robust leveled topological sorts than I had written

Anyway – if you grab the files from:

http://skvidal.fedorapeople.org/misc/buildorder/

And run:

python buildorder.py /path/to/*.src.rpm

it will look up the interdependencies of the src.rpm to figure out a
build order. It outputs a bunch of different things:
1. a flat build order
2. a build order broken out by groups – you can build all the pkgs in
any group in parallel provided that all the pkgs in the previous group
have finished building.
3. outputs lists of direct loops between srpms.
4. probably will output A LOT of noise and garbage from the rpm
specfile parsing from the rpm.spec() module

But it might be worth a look at and, ideally, patches to make it a bit
more robust.

If you have a set of pkgs which you need to build but you can’t figure
out the buildorder this might help you out.

I’d love to know how often it is right or ‘right enough’.

Known Issues:
1. some spec files make the rpm.spec() parsing break in interesting
ways – sometimes tracing back
2. if a pkg is not dependent on any other pkg and nothing else depends
on it – they get lumped in the last grouping. Not really an issue -
just something someone noticed and was surprised.
3. It will handle file-buildreqs not at all, it will handle virtual
provide buildreqs, not at all, if your buildreqs are REALLY picky about
requiring <= Version – it will ignore all of that.
4. I fully expect that 2 or more level circular build deps (foo req bar
req baz req quux) will not be detected but will make the topological
sort function die). If so…. tough… go fix your packaging.

Anyway – give it a run and see if it helps you solve a problem.

If it does let me know about it. Some of us are curious if this could
fit well in mockchain or wrapped around/in mockchain.

adding an openstack cinder volume server to an existing cloud with an existing cinder setup

Mon, 29 Apr 2013 23:04:30 GMT

We needed more space for cinder and had no nice way to expand it on our existing cinder server so after banging my head a bit I got assistance from Giulio Fidente who was able to show me a working config that let me figure out what I was missing. Below I document it so others might be able to find it, too.

NOTE: this works under folsom on rhel 6.4. I cannot vouch for anything else -but Giulio had it running on grizzly I think so…

Usage:

You have an existing cinder server setup and running – which includes
a volume server, an api service and a scheduler service. You need to
add more space and you have a system where that can run.

Here’s all you need to do:

1. install openstack-cinder on the server you want to be a new volume server

2. make sure your new system can access the mysql server on your primary
controller system

3. make sure tgtd knows to import the files /etc/cinder/volumes

add
include /etc/cinder/volumes/*
to:
/etc/tgt/targets.conf

4. make sure your other computer nodes can access the iscsi-target port
iscsi-target 3260/tcp on the system you want to add as an cinder-volume server

5. setup your /etc/cinder/cinder.conf
example:

[DEFAULT]
sql_connection = mysql://cinder_user:cinder_pass@mysqlhost/cinder
api_paste_config=/etc/cinder/api-paste.ini
auth_strategy = keystone
rootwrap_config = /etc/cinder/rootwrap.conf
rpc_backend = cinder.openstack.common.rpc.impl_qpid
qpid_hostname = qpid_hostname_ip_here
volume_group = cinder-volumes
iscsi_helper = tgtadm
iscsi_ip_address = my_volume_ip
logdir = /var/log/cinder
state_path = /var/lib/cinder
lock_path = /var/lib/cinder/tmp
volumes_dir = /etc/cinder/volumes

6. start tgtd and openstack-cinder-volume

service tgtd start
service openstack-cinder-volume start

7. check out /var/log/cinder/volume.log

8. Verifying it worked:
on your cloud controller run:
cinder-manage host list
you should see all of your volume servers there.

9. creating a volume. – just make a volume as usual – the scheduler
should default to the volume server with the most space available

10. on your new cinder-volume server run lvs to look for the new volume.

Things I Learned while building f19alpha imgs for our openstack cloud

Sat, 27 Apr 2013 03:09:06 GMT

Things I learned today:

1. the predictable network device naming stuff in systemd is kinda arbitrary when it comes to cloud imgs that may run on a variety of virt systems – so to turn it off just add this to your %post in your kickstart:

# disable systemd ‘predictable’ device names for networks w/a hammer

ln -s /dev/null /etc/udev/rules.d/80-net-name-slot.rules

cat > /etc/sysconfig/network-scripts/ifcfg-eth0 << EOF
DEVICE="eth0"
BOOTPROTO="dhcp"
ONBOOT="yes"
TYPE="Ethernet"
EOF

That last bit is just to make a generic ifcfg-eth0 so ifup eth0 works normally.

2. the hostonly initramfs that dracut makes now plays up when you are moving an image around. make sure you add

dracut-nohostonly

to %packages to get it to behave as you’d expect

3. if you don’t have a lot of memory then you may not want tmpfs for /tmp - to turn that off just do:

systemctl mask tmp.mount

in %post and it will be as you’d expect.

4. syslinux-extlinux is WAY nicer and simpler to use than grub2

Thanks to Mattdm for making the syslinux-extlinux option for anaconda happen.

ansible rpm compare

Thu, 25 Apr 2013 04:08:20 GMT

A while back I wrote this for func – and I found I needed it ported to ansible.

I enhanced it to make it take more than just 2 systems. It can now compare any number of systems to the base system

http://fedorapeople.org/cgit/skvidal/public_git/scripts.git/tree/ansible/ans_rpm_compare.py

Takes a first argument of your ‘baseline’ host that’s the host all the other hosts package sets will be compared to.

It grabs the list of rpms installed on each system (just using rpm -qa, I’m lazy, or I could have used the yum list=installed option)

It transforms that output into a set – then does a difference on them each way.

Output looks like this

$ ans_rpm_compare.py app01.phx2.fedoraproject.org app02.phx2.fedoraproject.org
Packages on app01.phx2.fedoraproject.org not on app02.phx2.fedoraproject.org
words-3.0-17.el6.noarch
fedmsg-relay-0.6.8-1.el6.noarch
gdb-7.2-60.el6.i686

Packages on app02.phx2.fedoraproject.org not on app01.phx2.fedoraproject.org

Trivial but should be straightforward to follow how it works in the code.

No idea where else to put it so it goes into my scripts git repo.

mailman archiver failure

Mon, 22 Apr 2013 18:04:50 GMT

If you see this traceback in your /var/log/mailman/error file

File “/usr/lib/mailman/Mailman/Queue/Runner.py”, line 120, in _oneloop
self._onefile(msg, msgdata)
File “/usr/lib/mailman/Mailman/Queue/Runner.py”, line 191, in _onefile
keepqueued = self._dispose(mlist, msg, msgdata)
File “/usr/lib/mailman/Mailman/Queue/ArchRunner.py”, line 73, in _dispose
mlist.ArchiveMail(msg)
File “/usr/lib/mailman/Mailman/Archiver/Archiver.py”, line 216, in ArchiveMail
h.processUnixMailbox(f)
File “/usr/lib/mailman/Mailman/Archiver/pipermail.py”, line 583, in processUnixMailbox
self.add_article(a)
File “/usr/lib/mailman/Mailman/Archiver/pipermail.py”, line 635, in add_article
article.parentID = parentID = self.get_parent_info(arch, article)
File “/usr/lib/mailman/Mailman/Archiver/pipermail.py”, line 669, in get_parent_info
if parentID and not self.database.hasArticle(archive, parentID):
File “/usr/lib/mailman/Mailman/Archiver/HyperDatabase.py”, line 273, in hasArticle
self.__openIndices(archive)
File “/usr/lib/mailman/Mailman/Archiver/HyperDatabase.py”, line 251, in __openIndices
t = DumbBTree(os.path.join(arcdir, archive + ‘-’ + i))
File “/usr/lib/mailman/Mailman/Archiver/HyperDatabase.py”, line 65, in __init__
self.load()
File “/usr/lib/mailman/Mailman/Archiver/HyperDatabase.py”, line 170, in load
self.dict = marshal.load(fp)
ValueError: bad marshal data

It is due to a corrupted archive database. Those live in /var/lib/mailman/archives/private/$list/database/*

In order to figure out which one it is – you have to run this:

#!/usr/bin/python

import os, sys
sys.path.insert(0, ‘/usr/lib/mailman’)

import Mailman.Archiver
import marshal
for fn in sys.argv[1:]:
if os.path.exists(fn):
c = marshal.load(open(fn))

against the files in the dir I mentioned above.

like this

python thatscript /var/lib/mailman/archives/private/$list/database/2013-April*

That will tell you if a file is busted, (it will print out an exception) but it won’t fix it.

You will probably need to run it against all of the current files for all the lists you have

Once you figure out which lists are broken you SHOULD be able to run

bin/arch –wipe listname /var/lib/archives/private/$list.mbox/$list.mbox

and have it recreate the whole thing.

polling/diffing instances in openstack

Wed, 27 Mar 2013 05:04:53 GMT

I’m trying to produce a simple list of instances on the fedora

openstack instance. I want to produce a list every 10m or so and diff

it against the last copy of that list and output the changes.

Here’s what I came up with:
http://fedorapeople.org/cgit/skvidal/public_git/scripts.git/tree/openstack/gather-diff-instances.py

it is based originally on nova-manage. It runs as root on the head system in our cloud and just dumps out json, then diffs the json.

Everything works but I’m trying to figure out if this is the ‘right’
way of going about this.
I thought about doing it via nova instead of using the nova-manage
direct-to-db api but I had 2 problems:

1. I would need to save the plaintext admin pw somewhere on disk to
poll for that info

2. or get a token which I would have to renew every 24 hours

We’re using the above the script as a simple cron job that lets us know
what things are changing in our cloud (who is bringing up new
instances, how many, what ips they are attaching to them, etc)

Additionally, is there a way in the db api to easily query the tenant and user info from keystone? I’d like to expand out the user uuid into username/project name.

gitproxy

Fri, 22 Mar 2013 22:10:41 GMT

gitproxy:
http://skvidal.fedorapeople.org/misc/gitproxy

Dealing with a potential problem we were trying to figure out a way to proxy/redirect git:// calls from one server to another one. This is a fairly ridiculous script I hacked up in the wee-small hours of thursday morning after talking to+Sitaram Chamarty on #git for a while.

I fully expect this won’t work well under load but it does seem to function in my small tests here.

diffing two ini files

Fri, 22 Mar 2013 17:04:33 GMT

Ever need to diff 2 ini files but their sections and options aren’t in the right order?

Well, I do. I googled but I couldn’t find anything trivially available that did this.

I swear I wrote this once before but I couldn’t find it when I looked through my dirs of misc scripts so:

http://fedorapeople.org/cgit/skvidal/public_git/scripts.git/tree/inidiff

hope it is useful to someone.

async actions in ansible playbooks

Thu, 7 Mar 2013 01:04:40 GMT

A number of people have been surprised by this feature, even though it is documented, so I thought I’d mention it.

Ansible can run actions async. This means it connects to the client system, starts the process and disconnects.

In general you would want all your plays to be synchronous (do thing X, wait for it to be done/watch it, do thing Y).

However, there are times when what you want to do will take a VERY long time or could kill your ssh connection off.

An example is a yum update:

tasks:

- name: yum update

action: command yum -y update

That can take a long time, depending on what’s going on. You want to monitor what it does, but you don’t want a timeout or a reset ssh session/network to kill off that process.

So what do you do? You make it async:

tasks:

- name: yum update

action: command yum -y update

async: 7200

poll: 15

That means – run yum -y update – wait for up to 7200s and poll every 15s to check on the status of the action.

Here’s where we’re using it in fedora:

http://infrastructure.fedoraproject.org/cgit/ansible.git/tree/playbooks/package-update.yml#n11

However, this means if your ssh or network were to die – the yum update process would still run to completion.

But if your connection does die and you cannot check on the status of the job what do you do?

Well -you can connect to any system as the user who was running the job and look in ~/.ansible_async

there will be a file in there for each job that was being run. It may just be a place holder and empty (if the job is still running) or it made be filled with the results if the job is finished.

Pretty handy for a variety of tasks.