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Old Shitty Arista eAPI/Capi <-> gRPC proxy

Our Arista 7148S does not support gRPC/OpenConfig, so we have to make our own damn gRPC proxy.

The schema is supposed to be 1:1 mapped to the JSON-RPC EAPI. This is just a dumb proxy.

PKI Introduction

This project is a testing ground for the HSCloud PKI setup. Long story short, all gRPC is mutually authenticated via TLS (server & client certs).

All certs for mutual auth have the following CN/SAN format:

For example, if principal maps into a 'group' and job into a 'user':

arista-proxy-dcr01u23.prod.c.example.com

job = arista-proxy-dcr01u23 principal = cluster-management-prod realm = c.example.com

The Realm is a DNS name that is global to all jobs that need mutual authentication.

The Principal is any name that carries significance for logical grouping of jobs. It can, but doesn't need to, group jobs by similar permissions.

The Job is any name that identifies uniquely (within the principal) a security endpoint that describes a single security policy for a gRPC endpoint.

The entire CN should be DNS resolvable into an IP address that would respond to gRPC requests on port 42000 (with a server TLS certificate that represents this CN) if the job represents a service.

This maps nicely to the Kubernetes Cluster DNS format if you set realm to svc.cluster.local. Then, principal maps to a Kubernetes namespace, and job maps into a Kubernetes service.

arista-proxy-dcr01u23.arista-prod.svc.cluster.local

job/service = arista-proxy-dcr01u23
principal/namespace = arista-prod
realm = svc.cluster.local

ACLs based on job/principal are yet to be implemented :).

Getting and Building

go get code.hackerspace.pl/q3k/arista-proxy
go generate code.hackerspace.pl/q3k/arista-proxy/proto
go build code.hackerspace.pl/q3k/arista-proxy

PKI Certs for Development

In production, those certs will be automatigacally provided for you by automation. In development, you'll have to do the following:

cd pki
./gen.sh

This will generate:

pki/ca.pem - CA certificate
pki/client{,-key}.pem - certificate and key for developer.humans.svc.cluster.local
pki/service{,-key}.pem - certificate and key for test.arista-proxy.svc.cluster.local

You will have to setup an /etc/hosts alias to make test.arista-proxy.svc.cluster.local resolve to your machine.

# cat /etc/hosts
...
127.0.0.1 test.arista-proxy.svc.cluster.local
...

You can then start arista-proxy with default flags and talk to it via gRPC:

./arista-proxy

alias grpc-dev="grpc -cacert $(pwd)/pki/ca.pem -key $(pwd)/pki/client-key.pem -cert $(pwd)/pki/client.pem"
grpc-dev test.arista-proxy.svc.cluster.local:42000 proto.AristaProxy.ShowVersion

Debug Status Page

The debug_address flag controls spawning an HTTP server useful for debugging. You can use it to inspect gRPC request and view general status information of the proxy.

Flags

./arista-proxy -help
Usage of ./arista-proxy:
  -alsologtostderr
    	log to standard error as well as files
  -arista_api string
    	Arista remote endpoint (default "http://admin:password@1.2.3.4:80/command-api")
  -debug_address string
    	Debug HTTP listen address, or empty to disable (default "127.0.0.1:42000")
  -listen_address string
    	gRPC listen address (default "127.0.0.1:43001")
  -log_backtrace_at value
    	when logging hits line file:N, emit a stack trace
  -log_dir string
    	If non-empty, write log files in this directory
  -logtostderr
    	log to standard error instead of files
  -pki_realm string
    	PKI realm (default "svc.cluster.local")
  -stderrthreshold value
    	logs at or above this threshold go to stderr
  -tls_ca_path string
    	Path to PKI CA certificate (default "pki/ca.pem")
  -tls_certificate_path string
    	Path to PKI service certificate (default "pki/service.pem")
  -tls_key_path string
    	Path to PKI service private key (default "pki/service-key.pem")
  -v value
    	log level for V logs
  -vmodule value
    	comma-separated list of pattern=N settings for file-filtered logging

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