Embedded Metrics Logging

src/lib.rs

@@ -1,4 +1,5 @@
 extern crate libc;
+mod log;
 use lazy_static::lazy_static;
 use libc::c_char;
 use std::collections::HashMap;
@@ -27,7 +28,7 @@ redhook::hook! {
                 }
             }
             if DEBUG {
-                println!("[crypteia] libcrypteia: initialized using LD_PRELOAD");
+                log::cloudwatch_metric("lib", "initialized", false, None);
             }
         });
         let env_value = redhook::real!(getenv)(name);
@@ -73,7 +74,7 @@ fn is_env_file() -> bool {
     let boo_value = metadata(ENV_FILE).is_ok();
     unsafe {
         if DEBUG {
-            println!("[crypteia] libcrypteia: is_env_file() -> {}", boo_value);
+            log::cloudwatch_metric("lib", "is_env_file", false, None);
         }
     }
     boo_value
@@ -96,7 +97,7 @@ fn read_env_file() {
     });
     unsafe {
         if DEBUG {
-            println!("[crypteia] libcrypteia: read_env_file()");
+            log::cloudwatch_metric("lib", "read_env_file", false, None);
         }
     }
     delete_file();
@@ -107,7 +108,7 @@ fn delete_file() {
     remove_file(ENV_FILE).unwrap();
     unsafe {
         if DEBUG {
-            println!("[crypteia] libcrypteia: delete_file()");
+            log::cloudwatch_metric("lib", "delete_file", false, None);
         }
     }
 }

src/log.rs

@@ -0,0 +1,39 @@
+use serde_json::json;
+use std::time::SystemTime;
+use std::time::UNIX_EPOCH;
+
+pub fn cloudwatch_metric(dimension: &str, name: &str, error: bool, error_message: Option<String>) {
+    let timestamp = SystemTime::now()
+        .duration_since(UNIX_EPOCH)
+        .unwrap()
+        .as_millis()
+        .to_string()
+        .parse::<u64>()
+        .unwrap();
+    let metric = serde_json::to_string(&json!(
+      {
+        "_aws": {
+          "Timestamp": timestamp,
+          "CloudWatchMetrics": [
+            {
+              "Namespace": "Crypteia",
+              "Dimensions": [["All", dimension]],
+              "Metrics": [
+                { "Name": name, "Unit": "Count"}
+              ]
+            }
+          ]
+        },
+        "All": "all",
+        dimension: dimension,
+        name: 1,
+        "ErrorMessage": error_message.unwrap_or("".to_string()),
+      }
+    ))
+    .unwrap();
+    if error {
+        eprintln!("{}", metric);
+    } else {
+        println!("{}", metric);
+    }
+}

src/main.rs

@@ -1,3 +1,4 @@
+mod log;
 mod ssm;
 use lambda_extension::{service_fn, Error, LambdaEvent, NextEvent};
 use std::collections::HashMap;
@@ -8,10 +9,10 @@ const ENV_FILE: &str = "/tmp/crypteia.json";
 
 #[tokio::main]
 async fn main() -> Result<(), Error> {
-    println!("[crypteia] main: Init");
+    log::cloudwatch_metric("main", "initialized", false, None);
     let env_vars: HashMap<String, String> = std::env::vars().collect();
     let env_map = ssm::get_envs(env_vars).await.unwrap();
-    println!("[crypteia] main: Fetched environment variables");
+    log::cloudwatch_metric("main", "fetched", false, None);
     write_envs_to_tmp_json(env_map);
     let func = service_fn(parameters_extension);
     lambda_extension::run(func).await
@@ -20,7 +21,7 @@ async fn main() -> Result<(), Error> {
 async fn parameters_extension(event: LambdaEvent) -> Result<(), Error> {
     match event.next {
         NextEvent::Shutdown(_e) => {
-            println!("[crypteia] main: Shutdown");
+            log::cloudwatch_metric("main", "shutdown", false, None);
         }
         NextEvent::Invoke(_e) => {}
     }

src/ssm.rs

@@ -1,3 +1,4 @@
+use crate::log;
 use anyhow::Result;
 use futures::future::join_all;
 use std::collections::HashMap;
@@ -30,9 +31,9 @@ pub async fn get_envs(env_vars: HashMap<String, String>) -> Result<HashMap<Strin
                         results.insert(key, value);
                     });
                 }
-                Err(error) => eprintln!("[crypteia] ssm: Parameter error {err}", err = error),
+                Err(error) => log::cloudwatch_metric("ssm", "error", true, Some(error.to_string())),
             },
-            Err(error) => eprintln!("[crypteia] ssm: JoinError {err}", err = error),
+            Err(error) => log::cloudwatch_metric("ssm", "error", true, Some(error.to_string())),
         }
     }
     Ok(results)
@@ -57,9 +58,14 @@ async fn ssm_get_parameter(
             }
         }
         Err(error) => {
-            eprintln!(
-                "[crypteia] ssm: Error calling ssm:GetParameter. Environment variable: {name} Path: {path} Error: {err}",
-                err = error
+            log::cloudwatch_metric(
+                "ssm",
+                "error",
+                true,
+                Some(format!(
+                    "Error calling ssm:GetParameter. Environment variable: {} Path: {} Error: {}",
+                    name, path, error
+                )),
             );
         }
     }
@@ -100,9 +106,14 @@ async fn ssm_get_parameters_by_path(
                 token = response.next_token;
             }
             Err(error) => {
-                eprintln!(
-                    "[crypteia] ssm: Error calling ssm:GetParametersByPath. Environment variable: {name} Path: {path} Error: {err}",
-                    err = error
+                log::cloudwatch_metric(
+                    "ssm",
+                    "error",
+                    true,
+                    Some(format!(
+                        "Error calling ssm:GetParametersByPath. Environment variable: {} Path: {} Error: {}",
+                        name, path, error
+                    )),
                 );
                 break;
             }