From 2d84059d7f44a442045e6c1c7baa59e35b34bbe5 Mon Sep 17 00:00:00 2001
From: Pavel Sviderski <me@psviderski.name>
Date: Mon, 24 Feb 2025 20:33:08 +1000
Subject: [PATCH] feat(dns): client for creating ingress records

---
 internal/cli/client/dns.go | 33 +++++++++++++++++++++++++++++
 internal/dns/api.go        | 18 ++++++++++++++++
 internal/dns/client.go     | 43 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 94 insertions(+)
 create mode 100644 internal/cli/client/dns.go

diff --git a/internal/cli/client/dns.go b/internal/cli/client/dns.go
new file mode 100644
index 00000000..b13c6dee
--- /dev/null
+++ b/internal/cli/client/dns.go
@@ -0,0 +1,33 @@
+package client
+
+import (
+	"context"
+	"fmt"
+	"uncloud/internal/machine/api/pb"
+)
+
+// TODO:
+func (cli *Client) CreateIngressRecords(ctx context.Context, serviceID string) ([]*pb.DNSRecord, error) {
+	// TODO:
+	//  - Inspect the service and get the list of machines it runs on.
+	//  - For each machine get the machine's public IP address(s).
+	//  - Update the wildcard DNS record for the service with the public IP addresses (call Cluster API).
+
+	req := &pb.CreateDomainRecordsRequest{
+		Records: []*pb.DNSRecord{
+			{
+				Name: "*",
+				Type: pb.DNSRecord_A,
+				// TODO: Get the public IP addresses of the machines running Caddy containers.
+				Values: []string{"1.2.3.4", "5.6.7.8"},
+			},
+			// TODO: Add AAAA record with routable IPv6 addresses of machines running Caddy containers.
+		},
+	}
+	resp, err := cli.CreateDomainRecords(ctx, req)
+	if err != nil {
+		return nil, fmt.Errorf("create cluster domain records in Uncloud DNS: %w", err)
+	}
+
+	return resp.Records, nil
+}
diff --git a/internal/dns/api.go b/internal/dns/api.go
index 6d8cfc01..ec160cc6 100644
--- a/internal/dns/api.go
+++ b/internal/dns/api.go
@@ -1,10 +1,28 @@
 package dns
 
+const (
+	RecordTypeA    RecordType = "A"
+	RecordTypeAAAA RecordType = "AAAA"
+)
+
+type RecordType string
+
 type DomainResponse struct {
 	Name  string `json:"name,omitempty"`
 	Token string `json:"token,omitempty"`
 }
 
+type RecordRequest struct {
+	Name   string     `json:"name,omitempty"`
+	Type   RecordType `json:"type,omitempty"`
+	Values []string   `json:"values,omitempty"`
+}
+
+type RecordResponse struct {
+	RecordRequest
+	FQDN string `json:"fqdn,omitempty"`
+}
+
 type AuthErrorResponse struct {
 	Status  int           `json:"status,omitempty"`
 	Message string        `json:"msg,omitempty"`
diff --git a/internal/dns/client.go b/internal/dns/client.go
index 146d6b27..3f253bab 100644
--- a/internal/dns/client.go
+++ b/internal/dns/client.go
@@ -1,6 +1,7 @@
 package dns
 
 import (
+	"bytes"
 	"encoding/json"
 	"errors"
 	"fmt"
@@ -17,6 +18,10 @@ type Client interface {
 	// ReserveDomain calls Uncloud DNS to reserve a new domain. It returns the domain, a token for authentication,
 	// and an error.
 	ReserveDomain(endpoint string) (string, string, error)
+
+	// CreateRecords calls Uncloud DNS to create or update DNS records based on the supplied RecordRequests
+	// for the specified domain.
+	CreateRecords(endpoint, domain, token string, records []RecordRequest) ([]RecordResponse, error)
 }
 
 // ErrAuthNoDomain indicates that a request failed authentication because the domain was not found.
@@ -55,6 +60,35 @@ func (c *client) ReserveDomain(endpoint string) (string, string, error) {
 	return domain, resp.Token, nil
 }
 
+func (c *client) CreateRecords(endpoint, domain, token string, records []RecordRequest) ([]RecordResponse, error) {
+	// TODO: update Uncloud DNS service to not use a leading dot for domain names.
+	if !strings.HasPrefix(domain, ".") {
+		domain = "." + domain
+	}
+	url := fmt.Sprintf("%s/domains/%s/records", endpoint, domain)
+
+	var resp []RecordResponse
+	for _, recordRequest := range records {
+		body, err := jsonBody(recordRequest)
+		if err != nil {
+			return resp, err
+		}
+
+		req, err := c.request(http.MethodPost, url, body, token)
+		if err != nil {
+			return resp, err
+		}
+
+		var recordResp RecordResponse
+		if err = c.do(req, &recordResp); err != nil {
+			return resp, err
+		}
+		resp = append(resp, recordResp)
+	}
+
+	return resp, nil
+}
+
 func (c *client) request(method string, url string, body io.Reader, token string) (*http.Request, error) {
 	req, err := http.NewRequest(method, url, body)
 	if err != nil {
@@ -116,3 +150,12 @@ func (c *client) do(req *http.Request, responseBody any) error {
 
 	return nil
 }
+
+func jsonBody(payload any) (io.Reader, error) {
+	buf := &bytes.Buffer{}
+	err := json.NewEncoder(buf).Encode(payload)
+	if err != nil {
+		return nil, err
+	}
+	return buf, nil
+}