Customize JCNR Configuration (Google Cloud Marketplace)
SUMMARY Read this topic to understand how to customize JCNR configuration using a ConfigMap.
JCNR ConfigMap
Starting with Juniper Cloud-Native Router (JCNR) Release 23.3, JCNR supports customizing configuration using a ConfigMap when deployed in L3 mode. In cloud-based deployments, in the event of a node failure, the JCNR pods may be spawned on newer or different nodes. A ConfigMap decouples the configuration parameters from node names and is based on node labels instead. This enables the JCNR CNI deployer to consume the configuration parameters, apply them to the cRPD configuration template and render the configuration, as long as a matching label is available for the node.A ConfigMap is an API object to store data in key-values pairs. A ConfigMap defines per node variables that are consumed by nodes matching the label. The key-value pairs are used to render the configuration via a go template. The configured template must be uploaded to the JCNR deployment wizard in the Google Cloud Marketplace.
You must apply the ConfigMap before installing JCNR to create cRPD pods with default or custom configuration. The cRPD pod must be deleted and respawned should you wish to apply the configuration parameters any time after JCNR installation. The configuration parameters are applied by default to any newly spawned cRPD pods.
Configuration Example
Sample ConfigMap and template files are provided below.
You define the key-value pair for
different node labels in your cluster. An example of the cRPD Config
Template file is provided below:
apiVersion: v1
kind: ConfigMap
metadata:
name: jcnr-params
namespace: jcnr
data:
jcnr1: |
{
"isoLoopbackAddr": "49.0004.1000.0000.0001.00",
"IPv4LoopbackAddr": "110.1.1.2",
"srIPv4NodeIndex": "2000",
"srIPv6NodeIndex": "3000",
"BGPIPv4Neighbor": "110.1.1.254",
"BGPLocalAsn": "64512"
}
jcnr2: |
{
"isoLoopbackAddr": "49.0004.1000.0000.0000.00",
"IPv4LoopbackAddr": "110.1.1.3",
"srIPv4NodeIndex": "2001",
"srIPv6NodeIndex": "3001",
"BGPIPv4Neighbor": "110.1.2.254",
"BGPLocalAsn": "64512"
}The key-value pairs you define in the annotations is used to
render the cRPD configuration via a go template. An example of the cRPD
Config Map template file is provided below:
apply-groups [custom];
groups {
custom {
interfaces {
lo0 {
unit 0 {
{{if .Params.isoLoopbackAddr}}
family iso {
address {{.Params.isoLoopbackAddr}};
}
{{end}}
family inet {
address {{.Params.IPv4LoopbackAddr}};
}
}
}
}
routing-options {
router-id {{.Params.IPv4LoopbackAddr}}
route-distinguisher-id {{.Params.IPv4LoopbackAddr}}
}
protocols {
isis {
interface all;
{{if and .Env.SRGB_START_LABEL .Env.SRGB_INDEX_RANGE}}
source-packet-routing {
srgb start-label {{.Env.SRGB_START_LABEL}} index-range {{.Env.SRGB_INDEX_RANGE}};
node-segment {
{{if .Params.srIPv4NodeIndex}}
ipv4-index {{.Params.srIPv4NodeIndex}};
{{end}}
{{if .Params.srIPv6NodeIndex}}
ipv6-index {{.Params.srIPv6NodeIndex}};
{{end}}
}
}
{{end}}
level 1 disable;
}
ldp {
interface all;
}
mpls {
interface all;
}
}
policy-options {
# policy to signal dynamic UDP tunnel attributes to BGP routes
policy-statement udp-export {
then community add udp;
}
community udp members encapsulation:0L:13;
}
protocols {
bgp {
group jcnrbgp1 {
type internal;
local-address {{.Params.IPv4LoopbackAddr}};
local-as {{.Params.BGPLocalAsn}};
neighbor {{.Params.BGPIPv4Neighbor}};
family inet-vpn {
unicast;
}
family inet6-vpn {
unicast;
}
}
}
}
routing-options {
dynamic-tunnels {
dyn-tunnels {
source-address {{.Params.IPv4LoopbackAddr}};
udp;
destination-networks {{.Params.BGPIPv4Neighbor}}/32;
}
}
}
}
}You can define additional cRPD configuration hierarchies in the template. The
values to be rendered from the ConfigMap defined in the
jcnr-params-configmap.yaml must be defined as
{{.Params.var-name}}. Any
environment variables, such as variables defined in
values.yaml, must be defined as
{{.Env.variable_name}}.
show configuration | display set command in the
cli mode to view the custom configuration you
applied.root@jcnr-01> show configuration
## Last commit: 2023-06-23 08:30:42 EDT by root
version 20230608.143922_builder.r1342735;
groups {
base { /* OMITTED */ };
custom {
interfaces {
lo0 {
unit 0 {
family inet {
address 110.1.1.2/32;
}
family iso {
address 49.0004.1000.0000.0001.00;
}
}
}
}
policy-options {
# policy to signal dynamic UDP tunnel attributes to BGP routes
policy-statement udp-export {
then {
community add udp;
}
}
community udp members encapsulation:0L:13;
}
routing-options {
route-distinguisher-id 110.1.1.2;
router-id 110.1.1.2;
dynamic-tunnels {
dyn-tunnels {
source-address 110.1.1.2;
udp;
destination-networks {
110.1.1.254/32;
}
}
}
}
protocols {
bgp {
group jcnrbgp1 {
type internal;
local-address 110.1.1.2;
family inet-vpn {
unicast;
}
family inet6-vpn {
unicast;
}
local-as 64512;
neighbor 110.1.1.254;
}
}
isis {
interface all;
source-packet-routing {
srgb start-label 400000 index-range 4000;
node-segment {
ipv4-index 2000;
ipv6-index 3000;
}
}
level 1 disable;
}
ldp {
interface all;
}
mpls {
interface all;
}
}
}
cni { /* OMITTED */ };
internal { /* OMITTED */ };
}
apply-groups [ custom base internal ]; Modifying the ConfigMap
If you wish to change the ConfigMap any time after JCNR installation, you must delete the cRPD pod and respawn it using the following command:kubectl patch sts kube-crpd-worker-sts -n jcnr -p '{"spec":{"template":{"metadata":{"annotations":{"configmap-reload/timestamp":"'$(date +%s)'"}}}}}'Troubleshooting
The cRPD pod continues to restart in CrashLoopBackOff state if
invalid configuration is rendered and applied via the go template. You can apply the
rendered configuration manually to a running cRPD pod to validate the configuration
and identify issues. For GCP deployment you can find the rendered config in
/config directory on the JCNR host as
juniper.conf.master.