chore(config): separate config from sources (#709)

# What?

Separates the configuration from sources, allowing it to be used in more
use cases.

# How?

Creates new default configuration and separates the environment
variables and YAML sources from the default.

# Why?

Make it easier to track changes in every source, as the field names
might be different to what they are used at the configuration level.

# Notes

I expect to abstract this even more by providing it as a crate which can
have features, that way customers can only use the sources and product
specific fields they need.

---------

Co-authored-by: Aleksandr Pasechnik <aleksandr.pasechnik@datadoghq.com>
Co-authored-by: Florentin Labelle <florentin.labelle@outlook.fr>

Author: 3 people

.gitlab/datasources/flavors.yaml

@@ -6,7 +6,7 @@ flavors:
     needs_layer_publish: true
     suffix: amd64
     layer_name_base_suffix: ""
-    max_layer_compressed_size_mb: 24
+    max_layer_compressed_size_mb: 25
     max_layer_uncompressed_size_mb: 54
 
   - name: arm64

bottlecap/src/bin/bottlecap/main.rs

@@ -920,7 +920,7 @@ fn start_metrics_flushers(
         api_key: resolved_api_key,
         aggregator: Arc::clone(metrics_aggr),
         metrics_intake_url_prefix: metrics_intake_url.expect("can't parse site or override"),
-        https_proxy: config.https_proxy.clone(),
+        https_proxy: config.proxy_https.clone(),
         timeout: Duration::from_secs(config.flush_timeout),
         retry_strategy: DsdRetryStrategy::Immediate(3),
     };
@@ -945,7 +945,7 @@ fn start_metrics_flushers(
                 api_key: api_key.clone(),
                 aggregator: metrics_aggr.clone(),
                 metrics_intake_url_prefix: metrics_intake_url.clone(),
-                https_proxy: config.https_proxy.clone(),
+                https_proxy: config.proxy_https.clone(),
                 timeout: Duration::from_secs(config.flush_timeout),
                 retry_strategy: DsdRetryStrategy::Immediate(3),
             };

bottlecap/src/config/env.rs

@@ -1,7 +1,10 @@
+use std::str::FromStr;
+
 use serde::{Deserialize, Deserializer};
+use serde_json::Value;
 use tracing::error;
 
-#[derive(Clone, Copy, Debug, PartialEq, Deserialize, Default)]
+#[derive(Clone, Copy, Debug, PartialEq, Default)]
 pub enum LogLevel {
     /// Designates very serious errors.
     Error,
@@ -42,20 +45,40 @@ impl LogLevel {
     }
 }
 
-#[allow(clippy::module_name_repetitions)]
-pub fn deserialize_log_level<'de, D>(deserializer: D) -> Result<LogLevel, D::Error>
-where
-    D: Deserializer<'de>,
-{
-    let s: String = Deserialize::deserialize(deserializer)?;
-    match s.to_lowercase().as_str() {
-        "error" => Ok(LogLevel::Error),
-        "warn" => Ok(LogLevel::Warn),
-        "info" => Ok(LogLevel::Info),
-        "debug" => Ok(LogLevel::Debug),
-        "trace" => Ok(LogLevel::Trace),
-        _ => {
-            error!("Unknown log level: {}, using warn", s);
+impl FromStr for LogLevel {
+    type Err = String;
+
+    fn from_str(s: &str) -> Result<Self, Self::Err> {
+        match s.to_lowercase().as_str() {
+            "error" => Ok(LogLevel::Error),
+            "warn" => Ok(LogLevel::Warn),
+            "info" => Ok(LogLevel::Info),
+            "debug" => Ok(LogLevel::Debug),
+            "trace" => Ok(LogLevel::Trace),
+            _ => Err(format!(
+                "Invalid log level: '{s}'. Valid levels are: error, warn, info, debug, trace",
+            )),
+        }
+    }
+}
+
+impl<'de> Deserialize<'de> for LogLevel {
+    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
+    where
+        D: Deserializer<'de>,
+    {
+        let value = Value::deserialize(deserializer)?;
+
+        if let Value::String(s) = value {
+            match LogLevel::from_str(&s) {
+                Ok(level) => Ok(level),
+                Err(e) => {
+                    error!("{}", e);
+                    Ok(LogLevel::Warn)
+                }
+            }
+        } else {
+            error!("Expected a string for log level, got {:?}", value);
             Ok(LogLevel::Warn)
         }
     }