Add support for gRPC in Kubernetes deployment

.gitignore

@@ -12,3 +12,9 @@ build/*
 
 .idea
 client-env.sh
+
+k8s/helm/certs/*
+!k8s/helm/certs/aoc2024-http.crt
+!k8s/helm/certs/aoc2024-http.key
+!k8s/helm/certs/aoc2024-grpc.crt
+!k8s/helm/certs/aoc2024-grpc.key

Dockerfile

@@ -16,6 +16,7 @@ ARG DAY
 COPY solutions/day${DAY} solutions/day${DAY}
 RUN go build -o app solutions/day${DAY}/main.go
 EXPOSE 3000
+EXPOSE 50051
 
 HEALTHCHECK \
     --start-interval=10s \

k8s/cert.config

@@ -0,0 +1,16 @@
+[req]
+distinguished_name = req_distinguished_name
+x509_extensions = v3_req
+prompt = no
+
+[req_distinguished_name]
+CN = *.aoc2024.se
+
+[v3_req]
+keyUsage = critical, digitalSignature, keyEncipherment
+extendedKeyUsage = serverAuth
+subjectAltName = @alt_names
+
+[alt_names]
+DNS.1 = *.aoc2024.se
+DNS.2 = *.grpc.aoc2024.se

k8s/create-cert.sh

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+# Creates a certificate for the Kubernetes ingress controller,
+# this is required by the nginx-ingress controller to enable HTTP/2,
+# and HTTP 2 is required for gRPC.
+#
+# The certificate is already created and checked into this repository,
+# but the command is left here as documentation. The checked in certificate
+# is valid for ~100 years.
+
+openssl req -x509 -nodes -days 36500 -newkey rsa:2048 \
+  -keyout k8s/helm/certs/aoc2024.key -out k8s/helm/certs/aoc2024.crt \
+  -subj "/CN=*.aoc2024.se/O=AdventOfCode" \
+  -config ./k8s/cert.config

k8s/helm/templates/day-deployment.yaml

@@ -31,7 +31,8 @@ spec:
           image: aoc2024-day{{ .day }}
           imagePullPolicy: Never
           ports:
-            - containerPort: {{ .containerPort | default 3000 }}
+            - containerPort: {{ .containerHttpPort | default 3000 }}
+            - containerPort: {{ .containerGrpcPort | default 50051 }}
 
 ---
 {{- end }}

k8s/helm/templates/day-ingress-grpc.yaml

@@ -0,0 +1,33 @@
+# An easier way to do this would be to generate one ingress resource
+# per service, similar to how we have done for deployments and services.
+# But now that I've got this working I think it's kinda clean, even though
+# ImplementationSpecific pathType is bit of a code smell.
+
+apiVersion: networking.k8s.io/v1
+kind: Ingress
+metadata:
+  name: aoc2024-ingress-grpc
+  annotations:
+    nginx.ingress.kubernetes.io/ssl-redirect: "true"
+    nginx.ingress.kubernetes.io/backend-protocol: "GRPC"
+spec:
+  ingressClassName: nginx
+  tls:
+    - secretName: tls-certificate
+      hosts:
+        {{- range .Values.days}}
+        - "day{{ .day }}.grpc.{{ $.Values.hostname }}"
+        {{- end }}
+  rules:
+  {{- range .Values.days }}
+    - host: "day{{ .day }}.grpc.{{ $.Values.hostname }}"
+      http:
+        paths:
+          - path: /
+            pathType: Prefix
+            backend:
+              service:
+                name: aoc2024-day{{ .day }}
+                port: { number: 50051 }
+  {{- end }}
+

k8s/helm/templates/day-ingress.yaml

@@ -7,19 +7,18 @@ apiVersion: networking.k8s.io/v1
 kind: Ingress
 metadata:
   name: aoc2024-ingress
-  annotations:
-    nginx.ingress.kubernetes.io/rewrite-target: /$2
 spec:
   ingressClassName: nginx
   rules:
-    - http:
+  {{- range .Values.days }}
+    - host: "day{{ .day }}.{{ $.Values.hostname }}"
+      http:
         paths:
-          {{- range .Values.days }}
-          - path: /day{{ .day }}(/|$)(.*)
-            pathType: ImplementationSpecific
+          - path: /
+            pathType: Prefix
             backend:
               service:
                 name: aoc2024-day{{ .day }}
-                port:
-                  number: 3000
-          {{- end }}
+                port: { name: http }
+  {{- end }}
+

k8s/helm/templates/day-service.yaml

@@ -14,9 +14,13 @@ spec:
     day: "{{ .day }}"
   ports:
     - protocol: TCP
-      port: {{ .servicePort | default 3000 }}
-      targetPort: {{ .containerPort | default 3000 }}
+      port: {{ .serviceHttpPort | default 3000 }}
+      targetPort: {{ .containerHttpPort | default 3000 }}
       name: http
+    - protocol: TCP
+      port: {{ .serviceGrpcPort | default 50051 }}
+      targetPort: {{ .containerGrpcPort | default 50051 }}
+      name: grpc
 
 ---
 {{- end }}

k8s/helm/templates/tls-certificate-secret.yaml

@@ -0,0 +1,8 @@
+apiVersion: v1
+kind: Secret
+metadata:
+  name: tls-certificate
+type: kubernetes.io/tls
+data:
+  tls.crt: {{ .Files.Get .Values.cert.crtFile | b64enc }}
+  tls.key: {{ .Files.Get .Values.cert.keyFile | b64enc }}

k8s/helm/values.yaml

@@ -1,150 +1,111 @@
+hostname: 'aoc2024.se'
+cert:
+  crtFile: 'certs/aoc2024.crt'
+  keyFile: 'certs/aoc2024.key'
+
 days:
   - day: '01'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
+    # These parameters are optional,
+    # set here with default values as an example.
+    containerHttpPort: 3000
+    serviceHttpPort: 3000
+    containerGrpcPort: 50051
+    serviceGrpcPort: 50051
 
   - day: '02'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '03'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '04'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '05'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '06'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '07'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '08'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '09'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '10'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '11'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '12'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '13'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '14'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '15'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '16'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '17'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '18'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '19'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '20'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '21'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '22'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '23'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '24'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1
 
   - day: '25'
     replicas: 2
-    containerPort: 3000
-    servicePort: 3000
     version: v1