Gloo Edge as an API Gateway

This repository contains my experimentation with Gloo Edge as an API Gateway for Cloud Native Kubernetes services.

Prerequisites

1. Docker Desktop
2. Kubectl
3. Glooctl
4. Helm
5. grpccurl

What is covered in this?

• Run Gloo Edge as an API Gateway on kube cluster
• Run a gRPC based microservice on kube cluster
• Configure the gRPC service for endpoints and function definitions
• Run a HTTP based microservice on kube cluster
• Configure the service discovery to scan for Swagger docs
• Run a virtual service and use that to route requests to each service

Steps for setup

# Install gloo edge as a Gateway using glooctl
$glooctl install gateway

gRPC Setup

# Create gRPC deployment and service exposing on port 8001
$kubectl apply -f grpc.yaml

# Label and enabled function discovery for gRPC
$kubectl label upstream -n gloo-system default-grpc-petstore-8001 discovery.solo.io/function_discovery=enabled

# Check if gRPC Services are listed
$kubectl get upstream -n gloo-system default-grpc-petstore-8001 -o yaml

HTTP Setup

# Create HTTP deployment and service exposing on port 8002
$kubectl apply -f http.yaml

# Check if HTTP Service is discovered and configured as upstream
$glooctl get upstream default-petstore-8002 --output kube-yaml

# Enabled swagger docs if any or any function discovery
$kubectl label namespace default  discovery.solo.io/function_discovery=enabled

# Check if swagger docs are found and populated the endpoints
$glooctl get upstream default-petstore-8002

Apply Routing

# Create Virtual Service for HTTP and gRPC routes
$kubectl apply -f virtual-service.yaml

Verification

gRPC Routing

# Check if ServerReflection and StoreService are listed properly
$grpcurl -plaintext $(glooctl proxy address --port http) list

# Describe all functions in Store Service
$grpcurl -plaintext $(glooctl proxy address --port http) describe solo.examples.v1.StoreService

# List items in store
$grpcurl -plaintext $(glooctl proxy address --port http) solo.examples.v1.StoreService/ListItems

# Test create a new item
$grpcurl -plaintext -d '{"item":{"name":"item1"}}' $(glooctl proxy address --port http) solo.examples.v1.StoreService/CreateItem

HTTP Routing

# List all pets
$curl $(glooctl proxy url)/all-pets

Additional Experiments

Prerequisites

1. OpenSSL

Server TLS

# Generate a certificate using OpenSSL
$openssl req -x509 -nodes -days 365 -newkey rsa:2048 -keyout tls.key -out tls.crt -subj "/CN=petstore.example.com"

# Add the generated cert to kube secret
$kubectl create secret tls upstream-tls --key tls.key --cert tls.crt --namespace gloo-system

# Add the cert to our virtual service from kube secret
$glooctl edit virtualservice --name vs --namespace gloo-system --ssl-secret-name upstream-tls --ssl-secret-namespace gloo-system

# Verify if HTTP service is working, using -k since it is Self Signed Certificate
$curl -k $(glooctl proxy url --port https)/all-pets

# Verify if gRPC service is working
$grpcurl $(glooctl proxy address --port https) solo.examples.v1.StoreService/ListItems