Skip to content

jclegatte/cmdb

BranchesTags
 
 

Repository files navigation

This repository contains the configuration management system for Blade Network Team. It contains the base of truth in data/. Jerikan is the piece of software generating configuration files from data and templates in templates/. It uses the list of devices in devices.yaml and build a scope for each device using classifier.yaml. Ansible playbooks to deploy generated files are in ansible/.

More details on use and rationale are available in a blog post.

Get started

Setup

On first invocation, docker-compose will automatically build and fetch the images. To force a rebuild of some of the images, use:

$ docker image rm --no-prune cmdb_jerikan:latest cmdb_ansible:latest

Build templates

$ rm -rf output
$ ./run-jerikan build

To limit to a few devices:

$ ./run-jerikan build --limit=gateway\?.ussfo03.blade-group.net,none

Get the scope of a device

To get the scope of a device (and also the search paths for YAML files):

$ ./run-jerikan -s scope to1-p2.ussfo03.blade-group.net
# Scope:
continent: us
environment: prod
groups:
- tor
- tor-bgp
- tor-bgp-compute
host: to1-p2.ussfo03
location: ussfo03
member: '1'
model: wedge100
os: cumulus
pod: '2'
shorthost: to1-p2

# Search paths:
# (host/to1-p2.ussfo03)
# (host/prod.ussfo03/to1-p2)
#  host/ussfo03/to1-p2
# (groups/tor-bgp-compute-cumulus-wedge100-member1)
# (groups/tor-bgp-cumulus-wedge100-member1)
# (groups/tor-cumulus-wedge100-member1)
# (groups/tor-bgp-compute-member1)
# (groups/tor-bgp-member1)
# (groups/tor-member1)
# (groups/tor-bgp-compute-prod.ussfo03-pod2)
# (groups/tor-bgp-prod.ussfo03-pod2)
# (groups/tor-prod.ussfo03-pod2)
# (groups/tor-bgp-compute-ussfo03-pod2)
# (groups/tor-bgp-ussfo03-pod2)
# (groups/tor-ussfo03-pod2)
# (groups/tor-bgp-compute-prod.ussfo03)
# (groups/tor-bgp-prod.ussfo03)
# (groups/tor-prod.ussfo03)
#  groups/tor-bgp-compute-ussfo03
# (groups/tor-bgp-ussfo03)
# (groups/tor-ussfo03)
# (groups/tor-bgp-compute-us)
# (groups/tor-bgp-us)
# (groups/tor-us)
# (groups/tor-bgp-compute-cumulus-wedge100)
#  groups/tor-bgp-cumulus-wedge100
# (groups/tor-cumulus-wedge100)
#  groups/tor-bgp-compute
#  groups/tor-bgp
# (groups/tor)
# (groups/prod.ussfo03)
#  groups/ussfo03
#  os/cumulus-wedge100
# (os/cumulus-ussfo03)
#  os/cumulus
#  common

Key lookup for a device

$ ./run-jerikan -s lookup to1-p2.ussfo03.blade-group.net system netbox
manufacturer: Edge-Core
model: Wedge 100-32X
role: net_tor_gpu_switch

Run Ansible

The main playbook is in ansible/playbooks/site.yaml. It should mostly only contains mapping between group of devices and roles. The inventory is generated by the none special device. To deploy the files generated from GitLab CI with Ansible, use:

./run-ansible-gitlab playbooks/site.yaml --diff --check --limit=gateway\?.ussfo03.blade-group.net

A limit has to be provided. Possible patterns could be:

  • --limit='gateway1.ussfo03.blade-group.net' to limit to a specific host
  • --limit='environment-prod:&adm-gateway' to limit to a specific group
  • --limit='environment-prod:&location-ussfo03:&tor:&member-1' to limit to a subset of a group in a location

Some tasks are also tagged to only apply a subset of configuration. Notably:

  • -t base will only apply base modifications (NTP, syslog, users, passwords...)
  • -t irr will only apply IRR updates
  • -t all,reboot will authorize a reboot of a device if needed

Host none also comes with additional tags to limit its scope. They all start with deploy:.

./run-ansible-gitlab will run against the data generated by GitLab CI for the current master. You need to login to GitLab registry to make it work. If you prefer to generate the data locally with Jerikan, use ./run-ansible instead. From time to time, you can cleanup fetched configurations:

$ docker image ls -q registry.gitlab.com/blade-group/infra/network/cmdb:outputs-\* | xargs docker image rm

Some tasks may need an access to Vault. Go to Vault, authenticate and get your token using the upper right menu with "Copy token". Then, use the following command before invoking ./run-ansible-gitlab or ./run-ansible (extra space before export ensures the token doesn't end in your history):

$  export VAULT_TOKEN=joi75209gdfukjlfg87gngf

Recipes

Deploy base configuration on JunOS

$ ./run-ansible-gitlab playbooks/site.yaml --limit=os-junos -t base --diff --check

Deploy complete configuration on edge1.* for JunOS:

$ ./run-ansible-gitlab playbooks/site.yaml --limit='os-junos:&member-1' -t irr --diff --check
$ ./run-ansible-gitlab playbooks/site.yaml --limit='os-junos:&member-1' -t irr
$ ./run-ansible-gitlab playbooks/site.yaml --limit='os-junos:&member-1' --diff --check
$ ./run-ansible-gitlab playbooks/site.yaml --limit='os-junos:&member-1'

To make it easier to see the differences, we first apply only changes for IRR (which may output large diffs), and then the complete configuration.

Deploy configuration on nat1.dfr1.blade-group.net

$ ./run-ansible-gitlab playbooks/site.yaml --limit=nat1.dfr1.blade-group.net -t all,reboot --diff --check

Deploy EVPN configuration on lab

$ ./run-ansible-gitlab playbooks/site.yaml --limit='environment-lab:&location-pa1' --diff --check

Update DNS records (Route53, PowerDNS, RIPE, ARIN)

$ ./run-ansible-gitlab playbooks/site.yaml --limit=none -t deploy:dns -v --check

Update IRR records (ARIN, APNIC, RIPE)

$ ./run-ansible-gitlab playbooks/site.yaml --limit=none -t deploy:irr -v --check

Synchronize Netbox

$ ./run-ansible-gitlab playbooks/site.yaml --limit=none -t deploy:netbox -v --diff --check

Use another base than master for ./run-ansible-gitlab

By default, ./run-ansible-gitlab will use the output compiled from master by GitLab. If needed, this is possible use an older version of master or the result of a merge request. For this, you need to retrieve the SHA of the commit to use as a base.

For older versions of master, the commit history as the information. Use the clipboard icon to retrieve the full SHA. Only the commits with a green checkmark will work. For MR, you can get the same information from the "Commits" tab. Only the top-most commit will work.

Then, use the following command:

$ SHA=87bf08251961d1bb783cfe0274f7e37a3d4ed175 ./run-ansible-gitlab playbooks/site.yaml --limit=none -t deploy:netbox --diff --check

If you have a merge request you want to apply, switch to your branch and use:

$ SHA=$(git rev-parse HEAD) ./run-ansible-gitlab ...

Get facts from a device

Sometimes you may need to get the whole facts list from a specific device. It can be retrieved by using:

./run-ansible playbooks/facts.yaml --limit="spine1-n1.sk1.*"

Coding

Namespaces

  • system: for system-related stuff (accounts, syslog servers)
  • topology: for topology-related stuff (interfaces, IP, neighbors)
  • bgp: for BGP-related stuff (peerings, transits)
  • build: for build-system-related stuff (templates, scripts)
  • apps: for apps-related stuff (applications vars)

Templates

Functions

There are are several additional functions:

  • devices() will return the list of devices matching the set of conditions provided as arguments using the scope. For example, devices("location==ch1", "groups==tor-evpn") will return the list of devices in Chicago behaving as a ToR switch with EVPN enabled. Accepted operators are == and !=. You can also omit the operator if you want the specified value to be equal to the one in the local scope. For example, devices("environment", "location", "groups==tor-evpn") is the canonical way to get ToR devices on the same environment/location than the current device.

  • lookup() will do a key lookup. It takes the namespace, the key and optionally, a device name. If no device name, the current device is assumed.

  • scope() will provide the scope of the provided device.

  • bgpq3() is building a prefix-list with bgpq3.

  • peeringdb() fetches information about the provided AS from PeeringDB.

If the namespace of the lookup function is bgptth, the value is computed for use with "BGP-to-the-host" design. The expected key is local:port remote:port with the following shortcuts allowed:

  • remote:port, local is assumed to be the current device or the device specified as a third argument in lookup() and the local port is assumed to not be needed;
  • local remote:port, the local port is assumed to not be needed;
  • :port remote, local is assumed to be the current device or the device specified as a third argument in lookup() and the remote port is assumed to not be needed;
  • an empty key will return only information about the local ASN;
$ ./run-jerikan -s lookup to1-sp7.ams1.blade-group.net bgptth ":xe-0/0/6 sh-172-24-67-15"
asn: 4203981007
private: 10.67.206.44/31
provisioning: 10.135.156.89/30
public: 100.67.206.44/31
$ ./run-jerikan -s lookup to1-sp7.ams1.blade-group.net bgptth ""
asn: 4203981007
$ ./run-jerikan -s lookup to1-sp7.ams1.blade-group.net bgptth "spine1-storage-n1:et-0/0/4"
asn: 4203981007
private: 10.67.239.9/31
public: 100.67.239.9/31

Filters

In addition to standard Jinja2 filters, Jerikan adds its own filters:

  • ipv returns the version of an address,
  • ippeer returns the peer address of a /31 or /30,
  • ipoffset computes an IP address as an offset from a provided base address,
  • torange converts a human-readable range like 4-10 to a list,
  • tolist converts anything not a list to a list of a single element (and does nothing if you already provide a list),
  • slugify transforms a string to only use alphanumeric characters,

The following filters from Ansible are also exposed:

  • regex_search
  • regex_replace
  • b64decode
  • cidr_merge
  • ipaddr
  • ipmath
  • ipv4 and ipv6
  • hwaddr
  • hash
  • password_hash
  • to_yaml, to_nice_yaml and to_json

Key-value store

It is possible to use a template as a value in the key-value store. You need to prefix the value with ~. This should not be abused but this can be used to have a generic configuration for a type of equipment with values specific for each equipment. For example:

# In common YAML
interfaces:
  "~bond0.{{ lookup('topology', 'vlans')['nat-spine1'] }}":
    address: "~{{ lookup('topology', 'addresses').spine1 }}"
  "~bond0.{{ lookup('topology', 'vlans')['nat-spine2'] }}":
    address: "~{{ lookup('topology', 'addresses').spine2 }}"

# In nat1 YAML
nat-address-1: 185.231.156.1/31
nat-address-2: 185.231.156.3/31

# In nat2 YAML
nat-address-1: 185.231.156.5/31
nat-address-2: 185.231.156.7/31

This also works for structured data:

# In groups/adm-gateway-l3/topology.yaml
interface-rescue:
  address: "~{{ lookup('topology', 'addresses').rescue }}"
  up:
    - "~ip route add default via {{ lookup('topology', 'addresses').rescue|ipaddr('first_usable') }} metric 4278198271 table public"
    - "~ip route add default via {{ lookup('topology', 'addresses').rescue|ipaddr('first_usable') }} table rescue"
    - "~ip rule add from {{ lookup('topology', 'addresses').rescue|ipaddr('address') }} table rescue priority 10"

# In groups/adm-gateway-sk1/topology.yaml
interfaces:
  ens1f0: "~{{ lookup('topology', 'interface-rescue') }}"
$ ./run-jerikan -s lookup gateway1.sk1.blade-group.net topology interfaces
ens1f0:
  address: 121.78.242.10/29
  up:
  - ip route add default via 121.78.242.9 metric 4278198271 table public
  - ip route add default via 121.78.242.9 table rescue
  - ip rule add from 121.78.242.10 table rescue priority 10
lo:1:
[...]

There is also a special notation for a list when you want to get the IPv6 address from an IPv4 address:

addresses:
  loopback:
    - 198.51.100.2/24
    - ~^ip6

This will be translated to:

addresses:
  loopback:
    - 198.51.100.2/24
    - 2406:3bc0:100:b1:a:de:198.51.100.2/120

This requires base-public-6 to be defined in topology.yaml.

Examples

BGP

peers:
  transit:
    MyTransit:
      authentication: PASSWORD
      asn: 64496
      irr: AS-MYTRANSIT
      max-prefixes-4: false
      max-prefixes-6: false
      monitored: true
      policy-name: "AS64496-SPECIFIC"
      raw-import-4: |
        term SomeTerm {
          from {
            route-filter 192.0.2.2/32 exact;
          }
      raw-import-6: |
        term SomeTerm {
          from {
            route-filter 2001:db8::2/128 exact;
          }
      remote:
        - 192.0.2.1
        - 2001:db8::1
      specific-import:
        - name: REMOTE-AS
          as-path: ".*64497.*"
          lp-delta: 50 #+/-
      specific-export:
        prepend: 2

Checks

Check scripts are executed from the main directory and are provided with the name of the device as an additional argument. We store them in checks/.

During development, you may want to speedup template generations by skipping checks with --skip-checks option.

Best practices

  • Never use underscore in key names in YAML files.
  • Use dotted notation if possible in Jinja2.
  • Use a space after {% and {{.
  • Use a space before %} and }}.
  • Use a space after comma in function calls.
  • Use spaces around = on assignment.

About

Jerikan: a configuration management system for network teams

vincent.bernat.ch/en/blog/2021-network-cmdb

Resources

Readme

License

View license
Activity

Stars

0 stars

Watchers

0 watching

Forks

0 forks
Report repository

Releases

No releases published

Packages

No packages published

Languages

  • Jinja 49.5%
  • Python 45.2%
  • Shell 4.1%
  • Dockerfile 1.2%