Fix auditd watchdog Json response format break by invalid control character issue (#22709)

Fix auditd watchdog Json response format break by invalid control character issue

Why I did it
auditd watchdog some time return an invalid Json response, which will break test case:

E Failed: Invalid JSON response from auditd watchdog: {
E "auditd_conf":"FAIL (sha1 = efcce7fdf80e5ef917c40d60a2b6de55c9cfb466 -, expected = 7cdbd1450570c7c12bdc67115b46d9ae778cbd76)",
E "syslog_conf":"FAIL (syslog.conf does not contain 'active = yes': Command 'nsenter --target 1 --pid --mount --uts --ipc --net grep '^active = yes' /etc/audit/plugins.d/syslog.conf' failed with status 1: )",
E "auditd_rules":"FAIL (rules sha1 = 93e0a1416d3c3e12c2a708abe20e58c55c8d6d62 -, expected 77e0d8ff297ab3089b234fcd97a20e1c05380f3e)",
E "auditd_service":"FAIL (auditd.service does not contain 'CPUQuota=10%': Command 'nsenter --target 1 --pid --mount --uts --ipc --net grep '^CPUQuota=10%' /lib/systemd/system/auditd.service' failed with status 1: )",
E "auditd_active":"OK",
E "rate_limit":"FAIL (rate_limit: enabled 1
E failure 1
E pid 109644
E rate_limit 2000
E backlog_limit 8192
E lost 0
E backlog 0
E backlog_wait_time 60000
E backlog_wait_time_actual 0
E loginuid_immutable 0 unlocked
E mismatch with config file setting: 1000)"
E } exception: Invalid control character at: line 7 column 44 (char 760)

Work item tracking
Microsoft ADO 32313402
How I did it
Escape result before build Json response:

How to verify it
Pass all test case.

Manually verify format issue fixed:
{
"auditd_conf":"FAIL (sha1 = efcce7fdf80e5ef917c40d60a2b6de55c9cfb466 -)",
"syslog_conf":"FAIL (syslog.conf does not contain 'active = yes': Command 'nsenter --target 1 --pid --mount --uts --ipc --net grep '^active = yes' /etc/audit/plugins.d/syslog.conf' failed with status 1: )",
"auditd_rules":"FAIL (rules sha1 = da39a3ee5e6b4b0d3255bfef95601890afd80709 -, expected f88174f901ec8709bacaf325158f10ec62909d13)",
"auditd_service":"FAIL (auditd.service does not contain 'CPUQuota=10%': Command 'nsenter --target 1 --pid --mount --uts --ipc --net grep '^CPUQuota=10%' /lib/systemd/system/auditd.service' failed with status 1: )",
"auditd_active":"OK",
"auditd_reload":"OK",
"rate_limit":"FAIL (rate_limit: enabled 1\nfailure 1\npid 332282\nrate_limit 2000\nbacklog_limit 8192\nlost 0\nbacklog 0\nbacklog_wait_time 60000\nbacklog_wait_time_actual 0\nloginuid_immutable 0 unlocked\n mismatch with config file setting: 1000)"
}

Author: liuh-80

dockers/docker-auditd-watchdog/watchdog/Cargo.lock

@@ -5,3 +5,4 @@ edition = "2021"
 
 [dependencies]
 regex = "1.11.1"
+serde_json = "1.0.140"

dockers/docker-auditd-watchdog/watchdog/Cargo.toml

@@ -176,24 +176,24 @@ fn main() {
                     println!("Received request: {}", req_str);
                 }
 
-                let conf_result      = check_auditd_conf();
-                let syslog_result    = check_syslog_conf();
-                let rules_result     = check_auditd_rules();
-                let srvc_result      = check_auditd_service();
-                let srvc_active      = check_auditd_active();
-                let reload_result    = check_auditd_reload_status();
-                let rate_limit_result = check_auditd_rate_limit_status();
+                let conf_result      = serde_json::to_string(&check_auditd_conf()).unwrap();
+                let syslog_result    = serde_json::to_string(&check_syslog_conf()).unwrap();
+                let rules_result     = serde_json::to_string(&check_auditd_rules()).unwrap();
+                let srvc_result      = serde_json::to_string(&check_auditd_service()).unwrap();
+                let srvc_active      = serde_json::to_string(&check_auditd_active()).unwrap();
+                let reload_result    = serde_json::to_string(&check_auditd_reload_status()).unwrap();
+                let rate_limit_result = serde_json::to_string(&check_auditd_rate_limit_status()).unwrap();
 
                 // Build a JSON object
                 let json_body = format!(
                     r#"{{
-  "auditd_conf":"{}",
-  "syslog_conf":"{}",
-  "auditd_rules":"{}",
-  "auditd_service":"{}",
-  "auditd_active":"{}",
-  "auditd_reload":"{}",
-  "rate_limit":"{}"
+  "auditd_conf":{},
+  "syslog_conf":{},
+  "auditd_rules":{},
+  "auditd_service":{},
+  "auditd_active":{},
+  "auditd_reload":{},
+  "rate_limit":{}
 }}"#,
                     conf_result,
                     syslog_result,