feat(http): add new URL formatting for PostgreSQL connections on ipv6 (#4783)

feat(http): add new URL formatting for PostgreSQL connections

Author: kubosuke

flypg/http.go

@@ -4,10 +4,10 @@ import (
 	"bytes"
 	"context"
 	"encoding/json"
-	"fmt"
 	"io"
 	"net"
 	"net/http"
+	"net/url"
 	"time"
 
 	"github.com/PuerkitoBio/rehttp"
@@ -16,14 +16,16 @@ import (
 	"github.com/superfly/flyctl/terminal"
 )
 
+const flypgPort = "5500"
+
 type Client struct {
 	httpClient *http.Client
 	BaseURL    string
 }
 
 // NewFromInstance creates a new Client that targets a specific instance(address)
 func NewFromInstance(address string, dialer agent.Dialer) *Client {
-	url := fmt.Sprintf("http://%s:5500", address)
+	url := formatPGBaseURL(address)
 	terminal.Debugf("flypg will connect to: %s\n", url)
 
 	return &Client{
@@ -32,6 +34,15 @@ func NewFromInstance(address string, dialer agent.Dialer) *Client {
 	}
 }
 
+func formatPGBaseURL(address string) string {
+	hostport := net.JoinHostPort(address, flypgPort)
+
+	return (&url.URL{
+		Scheme: "http",
+		Host:   hostport,
+	}).String()
+}
+
 func newHttpClient(dialer agent.Dialer) *http.Client {
 	transport := &http.Transport{
 		DialContext: func(ctx context.Context, network, addr string) (net.Conn, error) {

flypg/http_test.go

@@ -0,0 +1,79 @@
+package flypg
+
+// Run: go test ./flypg   (repo root) or cd flypg && go test .
+//
+// Do not run go test flypg/http_test.go — that compiles only this file, so
+// NewFromInstance and flypgPort from http.go are undefined.
+
+import (
+	"net/url"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFormatPGBaseURL_IPv4(t *testing.T) {
+	client := NewFromInstance("192.168.1.1", nil)
+	assert.Equal(t, "http://192.168.1.1:5500", client.BaseURL)
+	assertParsableFlyPGURL(t, client.BaseURL, "192.168.1.1", "5500")
+}
+
+func TestFormatPGBaseURL_IPv6(t *testing.T) {
+	client := NewFromInstance("fdaa:2:be18:a7b:620:7ff8:9a20:2", nil)
+	assert.Equal(t, "http://[fdaa:2:be18:a7b:620:7ff8:9a20:2]:5500", client.BaseURL)
+	assertParsableFlyPGURL(t, client.BaseURL, "fdaa:2:be18:a7b:620:7ff8:9a20:2", "5500")
+}
+
+func TestFormatPGBaseURL_Hostname(t *testing.T) {
+	client := NewFromInstance("myapp.internal", nil)
+	assert.Equal(t, "http://myapp.internal:5500", client.BaseURL)
+	assertParsableFlyPGURL(t, client.BaseURL, "myapp.internal", "5500")
+}
+
+func TestFormatPGBaseURL_Table(t *testing.T) {
+	port := flypgPort
+	tests := []struct {
+		name         string
+		address      string
+		wantBaseURL  string
+		wantHostname string
+	}{
+		{
+			name:         "ipv4",
+			address:      "10.0.0.1",
+			wantBaseURL:  "http://10.0.0.1:5500",
+			wantHostname: "10.0.0.1",
+		},
+		{
+			name:         "ipv6_compressed",
+			address:      "2001:db8::1",
+			wantBaseURL:  "http://[2001:db8::1]:5500",
+			wantHostname: "2001:db8::1",
+		},
+		{
+			name:         "hostname",
+			address:      "pg.example.internal",
+			wantBaseURL:  "http://pg.example.internal:5500",
+			wantHostname: "pg.example.internal",
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := NewFromInstance(tt.address, nil).BaseURL
+			assert.Equal(t, tt.wantBaseURL, got)
+			assertParsableFlyPGURL(t, got, tt.wantHostname, port)
+		})
+	}
+}
+
+// assertParsableFlyPGURL checks the base URL parses and Hostname/Port match expectations
+// (same rules as net/http for dialing).
+func assertParsableFlyPGURL(t *testing.T, raw, wantHostname, wantPort string) {
+	t.Helper()
+	u, err := url.Parse(raw)
+	require.NoError(t, err)
+	assert.Equal(t, "http", u.Scheme)
+	assert.Equal(t, wantHostname, u.Hostname())
+	assert.Equal(t, wantPort, u.Port())
+}