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Homer
Homer (previously jnt) is our homemade network configuration manager.
It takes variables from Netbox and yaml files, run them through jinja templates to generate Juniper compatible configuration.
Homer can then send those configurations to selected network devices, for a diff or a safe commit.
The tool is written to not be Wikimedia specific. It only supports Junos but can easily be extended to other platforms.
Its doc is available on https://doc.wikimedia.org/homer/master/
Its code on Gerrit https://gerrit.wikimedia.org/g/operations/software/homer
Its bug and feature requests on Phabricator: https://phabricator.wikimedia.org/tag/homer/
This page focuses on Wikimedia's deployment.
Deployment
Homer is deployed via Puppet and Scap to the cumin (fleet management) hosts.
You can find its deploy repository here https://gerrit.wikimedia.org/g/operations/software/homer/deploy
And its Puppet module there https://gerrit.wikimedia.org/r/plugins/gitiles/operations/puppet/+/production/modules/homer
In addition it's available on Pypi: https://pypi.org/project/homer/
Releasing a new version
- Make a release patch updating the changelog (see this example patch).
- Once it's merged, update the local checkout and make a git tag. Ideally an annotated one (requires a GPG key and have git configured to use it, see
signingkey
):
$ RELEASE=v0.1.0
$ git tag -s -a "${RELEASE}" -m "${RELEASE}" -m "[Release Notes](CHANGELOG.rst)"
- Push the generated tag:
git push origin "${RELEASE}"
- Move to the
homer-deploy
checkout:
$ cd src/
$ git pull
$ git log -1 # to check to be at the right commit
$ cd ..
# At this point git status would show that there is a diff for the 'src' path, indicating the different SHA1 of the git submodule
# Ensure that docker is running
$ make -f Makefile.build all
# Verify that the generated wheels are correct
# At this point the frozen-requirements.txt file will most likely have some changes and the artifacts/artifacts.stretch.tar.gz will be different
git add .
git commit -m "Release ${RELEASE}"
git review
- Once the above patch has been merged (C+2, V+2 + submit), move to the deployment server in
/srv/deployment/homer/deploy
- Pull the latest changes:
git pull
- Verify that in the
src/
directory we're at the correct commit (check also withgit status
) - Deploy the new release:
scap deploy --verbose "Homer release v... - T..."
Daily diffs (not ready yet)
A cron job will run Homer every day to compare the live network configuration with our intended state. Any discrepancies will be emailed to someone (ideally a list) to be fixed.
Usage 🚀
Making changes
Note that Homer explicitly asks you when its about to modify the live network configuration (Type "yes" to commit, "no" to abort.
) and will prompt you with a diff of the changes beforehand.
Editing the private repository
Manually edit then commit the files on ssh://cumin1001.eqiad.wmnet:/srv/homer/private .
git will sync them with the other cumin host. And will email a summary of the changes to Riccardo (TODO: change it to SREs).
Make sure to mirror all your changes on the mock-private repo: https://gerrit.wikimedia.org/g/operations/homer/mock-private
This repository doesn't have CI, please be extra careful.
Editing the public repository
Similar to our other public repositories, send CRs to https://gerrit.wikimedia.org/g/operations/homer/public , try not to +2 your changes.
This repository doesn't have CI yet, please be extra careful.
Editing Netbox
Data is also pulled from Netbox, always make sure that Netbox accurate before using Homer.
Running Homer from cumin hosts (recommended)
Get familiar with the command line: https://doc.wikimedia.org/homer/master/homer.html everything else is taken care of.
The public repository is regularly updated by Puppet.
When pushing configurations, homer will ssh to the network devices using the Homer user. You need to be in the ops group to be able to use its private key.
Some examples:
homer "*" diff
All deviceshomer "cr*ams*" diff
esams and knams core routershomer "mr*" commit "My commit message"
All management routers
Running Homer from your local machine (less recommended)
- Clone the public repo: https://gerrit.wikimedia.org/g/operations/homer/public
- Clone private repo: ssh://cumin1001.eqiad.wmnet:/srv/homer/private
- Install Homer with either:
pip install homer
https://gerrit.wikimedia.org/g/operations/homer
+python3 setup.py install
(if you live on the edge)
- Create your configuration file to match https://doc.wikimedia.org/homer/master/configuration.html
- Get familiar with the command line: https://doc.wikimedia.org/homer/master/homer.html
When pushing configurations, your machine will ssh directly to the network devices, which mean that you have to have an account there, with the proper permissions.
It's common to test a change locally with the "diff" option. Once satisfied with the result, please merge your change on Gerrit before pushing them with the "commit" action.
Style guides
YAML files
TBD
Templates
It's ok to give up on indentation.
Network configuration coverage
CR
Done
groups {}
system {}
logical-systems {}
services {}
snmp {}
forwarding-options {}
protocols {
ospf {}
ospf3 {}
lldp {}
}
policy-options {}
firewall {}
routing-instances {}
TODO
interfaces {} # (Partial) https://gerrit.wikimedia.org/r/c/operations/homer/public/+/547584
routing-options {} # (Partial) https://gerrit.wikimedia.org/r/c/operations/homer/public/+/547587
apply-groups [ re0 re1 ]; # https://gerrit.wikimedia.org/r/#/c/operations/homer/public/+/549690
chassis {} # (Partial) https://gerrit.wikimedia.org/r/c/operations/homer/public/+/550389
protocols {
router-advertisement {}
bgp {} # Out of scope
pim {} # https://gerrit.wikimedia.org/r/c/operations/homer/public/+/549689
}
ASW
Done
system {}
snmp {}
protocols {}
routing-options {}
virtual-chassis {}
vlans {}
TODO
chassis {} # https://gerrit.wikimedia.org/r/c/operations/homer/public/+/550389
interfaces {}
MR
Done
groups {}
system {}
snmp {}
protocols {}
routing-options {}
policy-options {}
security {
zones {}
alg {}
forwarding-options {}
screen {}
}
TODO
interfaces {}
security {
address-book {} # Capirca?
nat {}
policies {} # Capirca?
}
routing-instances {}
applications {} # Capirca?
MSW
Done
system {}
snmp {}
protocols {}
routing-options {}
vlans {}
TODO
interfaces {}
Common/known issues
(Almost) None.
- The "commit" action doesn't work on the SRXs and the MX104, it will do the Juniper's "commit confirmed 2", but not the "commit check" to make the change permanent.
- Ignore the "Unable to determine FQDN for device" errors.