Landscape tests: switch to templates

We were modifying the fixtures too much:
- find and replace for certificate
- appending the hostagent URL section

This meant that the config in the fixture bore little similarity to
the one being used in the end. I switched to templates for the sake of
clarity. Now the fixtures look much more like the final config.

windows-agent/internal/proservices/landscape/landscape_test.go

@@ -20,6 +20,7 @@ import (
 	"strings"
 	"sync"
 	"testing"
+	"text/template"
 	"time"
 
 	landscapeapi "github.com/canonical/landscape-hostagent-api"
@@ -47,6 +48,11 @@ func TestMain(m *testing.M) {
 	defer os.Exit(exit)
 }
 
+const defaultLandscapeConfig = `
+[host]
+url = "{{ .HostURL }}"
+`
+
 func TestConnect(t *testing.T) {
 	if wsl.MockAvailable() {
 		t.Parallel()
@@ -129,20 +135,15 @@ func TestConnect(t *testing.T) {
 				landscapeAgentUID: tc.uid,
 			}
 
-			out, err := os.ReadFile(filepath.Join(golden.TestFixturePath(t), "landscape.conf"))
+			in, err := os.ReadFile(filepath.Join(golden.TestFixturePath(t), "landscape.conf"))
 			if errors.Is(err, os.ErrNotExist) {
-				// This fixture is not compulsory
-				out = []byte{}
+				// Use the default conf for testing
+				in = []byte(defaultLandscapeConfig)
 				err = nil
 			}
 			require.NoError(t, err, "Setup: could not load landscape config")
 
-			conf.landscapeClientConfig = string(out)
-			if !tc.noLandscapeURL {
-				conf.landscapeClientConfig = fmt.Sprintf("[host]\nurl=%q\n\n%s", lis.Addr(), conf.landscapeClientConfig)
-			}
-
-			conf.landscapeClientConfig = strings.ReplaceAll(conf.landscapeClientConfig, "%CERTPATH%", certPath)
+			conf.landscapeClientConfig = executeLandscapeConfigTemplate(t, string(in), certPath, lis.Addr())
 
 			if !tc.serverNotAvailable {
 				//nolint:errcheck // We don't care about these errors
@@ -295,7 +296,7 @@ func TestSendUpdatedInfo(t *testing.T) {
 
 			conf := &mockConfig{
 				proToken:              "TOKEN",
-				landscapeClientConfig: fmt.Sprintf("[host]\nurl=%q\n", lis.Addr()),
+				landscapeClientConfig: executeLandscapeConfigTemplate(t, defaultLandscapeConfig, "", lis.Addr()),
 			}
 
 			//nolint:errcheck // We don't care about these errors
@@ -463,7 +464,7 @@ func TestAutoReconnection(t *testing.T) {
 
 	conf := &mockConfig{
 		proToken:              "TOKEN",
-		landscapeClientConfig: fmt.Sprintf("[host]\nurl=%q\n", lis.Addr()),
+		landscapeClientConfig: executeLandscapeConfigTemplate(t, defaultLandscapeConfig, "", lis.Addr()),
 	}
 
 	db, err := database.New(ctx, t.TempDir(), conf)
@@ -599,7 +600,7 @@ func TestReceiveCommands(t *testing.T) {
 
 			conf := &mockConfig{
 				proToken:              "TOKEN",
-				landscapeClientConfig: fmt.Sprintf("[host]\nurl=%q\n", lis.Addr()),
+				landscapeClientConfig: executeLandscapeConfigTemplate(t, defaultLandscapeConfig, "", lis.Addr()),
 			}
 
 			db, err := database.New(ctx, t.TempDir(), conf)
@@ -662,6 +663,25 @@ func TestReceiveCommands(t *testing.T) {
 	}
 }
 
+func executeLandscapeConfigTemplate(t *testing.T, in string, certPath string, url net.Addr) string {
+	t.Helper()
+
+	tmpl := template.Must(template.New(t.Name()).Parse(in))
+
+	data := struct {
+		CertPath, HostURL string
+	}{
+		CertPath: certPath,
+		HostURL:  url.String(),
+	}
+
+	out := bytes.Buffer{}
+	err := tmpl.Execute(&out, data)
+	require.NoError(t, err, "Setup: could not generate Landscape config from template")
+
+	return out.String()
+}
+
 const (
 	testAppx       = "CanonicalGroupLimited.Ubuntu22.04LTS" // The name of the Appx
 	testDistroAppx = "Ubuntu-22.04"                         // The name used in `wsl --install <DISTRO>`

windows-agent/internal/proservices/landscape/testdata/TestConnect/error_when_the_landscape_URL_cannot_be_retrieved/landscape.conf

@@ -0,0 +1,3 @@
+[client]
+hello=world
+tags=wsl

windows-agent/internal/proservices/landscape/testdata/TestConnect/error_when_the_ssl_certificate_cannot_be_read/landscape.conf

@@ -1,2 +1,5 @@
 [client]
-ssl_public_key = testdata/TestConnect/this_path_does_not_exist/certificate.pem
+ssl_public_key = testdata/TestConnect/this_path_does_not_exist/certificate.pem
+
+[host]
+url = {{ .HostURL }}

windows-agent/internal/proservices/landscape/testdata/TestConnect/error_when_the_ssl_certificate_is_not_valid/landscape.conf

@@ -1,2 +1,5 @@
 [client]
-ssl_public_key = %CERTPATH%/bad-certificate.pem
+ssl_public_key = {{ .CertPath }}/bad-certificate.pem
+
+[host]
+url = {{ .HostURL }}

windows-agent/internal/proservices/landscape/testdata/TestConnect/success_with_an_ssl_certificate/landscape.conf

@@ -1,2 +1,5 @@
 [client]
-ssl_public_key = %CERTPATH%/cert.pem
+ssl_public_key = {{ .CertPath }}/cert.pem
+
+[host]
+url = {{ .HostURL }}

windows-agent/internal/proservices/landscape/testdata/TestConnect/success_with_non-empty_config/landscape.conf

@@ -1,3 +1,6 @@
 [client]
 hello=world
-tags=wsl
+tags=wsl
+
+[host]
+url = {{ .HostURL }}