configure public key and related license variables at build time (#22202)

Instead of being completely hardcoded, public key is now set at build time according to build tag (test key if `testlicensekey` tag is passed to go build, production key otherwise). A `isProdLicensePublicKey` is also available for determining if the prod license key is being used. It is needed for choosing whether to point to production or test environment CWS.

The test license key and CWS url values in this value are set to production values in this PR, but will be updated to the test values once we are ready to do the necessary updates to test environment spinwicks.

utils/license-public-key-test.txt

@@ -0,0 +1,9 @@
+-----BEGIN PUBLIC KEY-----
+MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyZmShlU8Z8HdG0IWSZ8r
+tSyzyxrXkJjsFUf0Ke7bm/TLtIggRdqOcUF3XEWqQk5RGD5vuq7Rlg1zZqMEBk8N
+EZeRhkxyaZW8pLjxwuBUOnXfJew31+gsTNdKZzRjrvPumKr3EtkleuoxNdoatu4E
+HrKmR/4Yi71EqAvkhk7ZjQFuF0osSWJMEEGGCSUYQnTEqUzcZSh1BhVpkIkeu8Kk
+1wCtptODixvEujgqVe+SrE3UlZjBmPjC/CL+3cYmufpSNgcEJm2mwsdaXp2OPpfn
+a0v85XL6i9ote2P+fLZ3wX9EoioHzgdgB7arOxY50QRJO7OyCqpKFKv6lRWTXuSt
+hwIDAQAB
+-----END PUBLIC KEY-----

utils/license-public-key.txt

@@ -0,0 +1,9 @@
+-----BEGIN PUBLIC KEY-----
+MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyZmShlU8Z8HdG0IWSZ8r
+tSyzyxrXkJjsFUf0Ke7bm/TLtIggRdqOcUF3XEWqQk5RGD5vuq7Rlg1zZqMEBk8N
+EZeRhkxyaZW8pLjxwuBUOnXfJew31+gsTNdKZzRjrvPumKr3EtkleuoxNdoatu4E
+HrKmR/4Yi71EqAvkhk7ZjQFuF0osSWJMEEGGCSUYQnTEqUzcZSh1BhVpkIkeu8Kk
+1wCtptODixvEujgqVe+SrE3UlZjBmPjC/CL+3cYmufpSNgcEJm2mwsdaXp2OPpfn
+a0v85XL6i9ote2P+fLZ3wX9EoioHzgdgB7arOxY50QRJO7OyCqpKFKv6lRWTXuSt
+hwIDAQAB
+-----END PUBLIC KEY-----

utils/license.go

@@ -22,16 +22,6 @@ import (
 	"github.com/mattermost/mattermost-server/v6/utils/fileutils"
 )
 
-var publicKey []byte = []byte(`-----BEGIN PUBLIC KEY-----
-MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAyZmShlU8Z8HdG0IWSZ8r
-tSyzyxrXkJjsFUf0Ke7bm/TLtIggRdqOcUF3XEWqQk5RGD5vuq7Rlg1zZqMEBk8N
-EZeRhkxyaZW8pLjxwuBUOnXfJew31+gsTNdKZzRjrvPumKr3EtkleuoxNdoatu4E
-HrKmR/4Yi71EqAvkhk7ZjQFuF0osSWJMEEGGCSUYQnTEqUzcZSh1BhVpkIkeu8Kk
-1wCtptODixvEujgqVe+SrE3UlZjBmPjC/CL+3cYmufpSNgcEJm2mwsdaXp2OPpfn
-a0v85XL6i9ote2P+fLZ3wX9EoioHzgdgB7arOxY50QRJO7OyCqpKFKv6lRWTXuSt
-hwIDAQAB
------END PUBLIC KEY-----`)
-
 var LicenseValidator LicenseValidatorIface
 
 func init() {

utils/license_public_key.go

@@ -0,0 +1,10 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+//go:build !testlicensekey
+
+package utils
+
+import _ "embed"
+
+//go:embed license-public-key.txt
+var publicKey []byte

utils/license_public_key_test_env.go

@@ -0,0 +1,13 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+//go:build testlicensekey
+
+package utils
+
+import _ "embed"
+
+// TODO: license-public-key-test.txt currently has the contents of the prod public key.
+// Change to the test public key when ready for dev images to use test license key.
+
+//go:embed license-public-key-test.txt
+var publicKey []byte