feat(sql): Add function to generate a URL safe ID

This adds a SQL function that generates a secure random ID of at least
14 characters suitable for use as a public or private ID. IDs generated
with the function will only contain characters from the unreserved
character set defined in RFC 3986 Section 2.3 making them safe for use
in a URL.

internal/db/schema/migrations/oss/postgres/80/01_history_domain.up.sql

@@ -30,4 +30,19 @@ begin;
   comment on domain wt_url_safe_id is
     'An ID that contains only URL safe characters';
 
+  -- wt_url_safe_id is a function that generates a secure random ID of 14
+  -- characters suitable for use as a public or private ID. IDs generated with
+  -- this function will only contain characters from the unreserved character set
+  -- defined in RFC 3986 Section 2.3 making them safe for use in a URL.
+  -- See https://www.rfc-editor.org/rfc/rfc3986.html#section-2.3
+  create function wt_url_safe_id() returns text
+  as $$
+    select wt_encode_base64_url_safe(gen_random_bytes(10));
+  $$ language sql
+     volatile
+     parallel safe -- all of the functions called are parallel safe
+     cost 1;       -- all of the functions called are cost 1
+  comment on function wt_url_safe_id is
+    'Returns a random ID of 14 characters containing URL safe characters only';
+
 commit;

internal/db/sqltest/tests/history/wt_url_safe_id_func.sql

@@ -0,0 +1,34 @@
+-- Copyright (c) HashiCorp, Inc.
+-- SPDX-License-Identifier: MPL-2.0
+
+begin;
+  select plan(7);
+  -- Verify the function exists and is declared properly
+  select has_function('wt_url_safe_id');
+  select volatility_is('wt_url_safe_id', 'volatile');
+  select isnt_strict('wt_url_safe_id');
+
+  create table test_table (
+    id wt_url_safe_id default wt_url_safe_id() primary key,
+    test_num integer not null
+  );
+
+  create function test_setup_data(count integer) returns integer
+  as $$
+  begin
+    for i in 1..count loop
+      insert into test_table (test_num) values (i);
+    end loop;
+    return count;
+  end;
+  $$ language plpgsql;
+
+  select is(test_setup_data(100000), 100000);
+  select is(count(*), 100000::bigint, 'test_table should have 100000 rows') from test_table;
+  select is(count(*), 0::bigint, 'no id should be longer than 14 characters')
+            from test_table where length(id) > 14;
+  select is(count(*), 0::bigint, 'no id should be shorter than 14 characters')
+            from test_table where length(id) < 14;
+
+  select * from finish();
+rollback;