Add frequency to cron scripts

Summary:
Originally I made cron scripts support only a cron expression to designate how frequently as script should be run. However, cron expressions look like they dont support second granularity.
Instead, we can have cronscripts support two modes: cron expression (probably unsupported for now, as this is more difficult), and hardcoded seconds.

Test Plan: This diff just adds some fields, but doesn't use them yet.

Reviewers: vihang, nserrino

Reviewed By: vihang

Signed-off-by: Michelle Nguyen <michellenguyen@pixielabs.ai>

Differential Revision: https://phab.corp.pixielabs.ai/D11030

GitOrigin-RevId: 1580e3a

src/cloud/cron_script/cronscriptpb/service.proto

@@ -58,6 +58,8 @@ message CronScript {
     string token = 7;
     // Whether the cron script is enabled.
     bool enabled = 8;
+    // How frequently a script should be run, if not specified via cron.
+    int64 frequency_s = 9;
 }
 
 // GetScriptRequest is a request to fetch information about a script in the cron script service.
@@ -96,6 +98,8 @@ message CreateScriptRequest {
     string configs = 4;
     // Token for the user/org for which this script is run on behalf of.
     string token = 5;
+    // How frequently a script should be run, if not specified via cron.
+    int64 frequency_s = 6;
 }
 
 // CreateScriptResponse is a response to a CreateScriptRequest.
@@ -113,6 +117,8 @@ message UpdateScriptRequest {
     google.protobuf.StringValue configs = 4;
     // Whether the cron script should be enabled.
     google.protobuf.BoolValue enabled = 5;
+    // How frequently a script should be run, if not specified via cron.
+    google.protobuf.Int64Value frequency_s = 6;
 }
 
 // UpdateScriptResponse is a response to an UpdateScriptRequest.

src/cloud/cron_script/schema/000002_add_frequency_cron_scripts_table.down.sql

@@ -0,0 +1,2 @@
+ALTER TABLE cron_scripts
+  DROP COLUMN frequency_s;

src/cloud/cron_script/schema/000002_add_frequency_cron_scripts_table.up.sql

@@ -0,0 +1,2 @@
+ALTER TABLE cron_scripts
+  ADD COLUMN frequency_s integer;