(core) Make improvements to audit logging

Summary:
 - Environment variables for configuring streaming have been replaced
   with the value of `audit_log_streaming_destinations` key, from the `configs`
   table.
     - The previous `hec` payload format has been replaced with a streaming
       destination with name `splunk`.
     - The previous `grist` payload format has been replaced with a streaming
       destination with name `other`.
 - Event streaming may now be configured on a per-site basis:
     - Events that specify a context with the site id are automatically streamed
       to that site's streaming destinations.
     - Events are still streamed to an installation's streaming destinations
       unconditionally.
 - Multiple streaming destinations may now be configured for an installation or site.
 - General improvements to the overall shape of audit events.
 - General improvements to the output of audit event documentation, including a new
   sample section with example JSON output of each events' details.

Test Plan: Server tests

Reviewers: paulfitz

Reviewed By: paulfitz

Subscribers: paulfitz

Differential Revision: https://phab.getgrist.com/D4383

app/common/Config-ti.ts

@@ -4,6 +4,21 @@
 import * as t from "ts-interface-checker";
 // tslint:disable:object-literal-key-quotes
 
+export const Config = t.iface([], {
+  "id": "string",
+  "key": "ConfigKey",
+  "value": "ConfigValue",
+  "createdAt": "string",
+  "updatedAt": "string",
+  "org": t.opt("ConfigOrg"),
+});
+
+export const ConfigOrg = t.iface([], {
+  "id": "number",
+  "name": "string",
+  "domain": t.union("string", "null"),
+});
+
 export const ConfigKey = t.lit("audit_log_streaming_destinations");
 
 export const ConfigValue = t.name("AuditLogStreamingDestinations");
@@ -12,15 +27,20 @@ export const AuditLogStreamingDestinations = t.array("AuditLogStreamingDestinati
 
 export const AuditLogStreamingDestination = t.iface([], {
   "id": "string",
-  "name": t.lit("splunk"),
+  "name": "AuditLogStreamingDestinationName",
   "url": "string",
   "token": t.opt("string"),
 });
 
+export const AuditLogStreamingDestinationName = t.union(t.lit("splunk"), t.lit("other"));
+
 const exportedTypeSuite: t.ITypeSuite = {
+  Config,
+  ConfigOrg,
   ConfigKey,
   ConfigValue,
   AuditLogStreamingDestinations,
   AuditLogStreamingDestination,
+  AuditLogStreamingDestinationName,
 };
 export default exportedTypeSuite;

app/common/Config.ts

@@ -1,6 +1,21 @@
 import ConfigsTI from "app/common/Config-ti";
 import { CheckerT, createCheckers } from "ts-interface-checker";
 
+export interface Config {
+  id: string;
+  key: ConfigKey;
+  value: ConfigValue;
+  createdAt: string;
+  updatedAt: string;
+  org?: ConfigOrg;
+}
+
+export interface ConfigOrg {
+  id: number;
+  name: string;
+  domain: string | null;
+}
+
 export type ConfigKey = "audit_log_streaming_destinations";
 
 export type ConfigValue = AuditLogStreamingDestinations;
@@ -9,11 +24,13 @@ export type AuditLogStreamingDestinations = AuditLogStreamingDestination[];
 
 export interface AuditLogStreamingDestination {
   id: string;
-  name: "splunk";
+  name: AuditLogStreamingDestinationName;
   url: string;
   token?: string;
 }
 
+export type AuditLogStreamingDestinationName = "splunk" | "other";
+
 export const ConfigKeyChecker = createCheckers(ConfigsTI)
   .ConfigKey as CheckerT<ConfigKey>;