Merge pull request #12 from fluencelabs/logger_env

Initialize logger based on the WASM_LOG env variable

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "fluence"
-version = "0.2.9"  # remember to update html_root_url
+version = "0.2.10"  # remember to update html_root_url
 description = "Fluence backend SDK for developing backend applications for the Fluence network"
 documentation = "https://docs.rs/fluence/"
 repository = "https://github.com/fluencelabs/rust-sdk"

crates/main/src/lib.rs

@@ -48,6 +48,8 @@ pub use export_allocator::deallocate;
 pub use logger::WasmLoggerBuilder;
 #[cfg(feature = "logger")]
 pub use logger::TargetMap;
+#[cfg(feature = "logger")]
+pub use logger::WASM_LOG_ENV_NAME;
 
 pub use result::get_result_ptr;
 pub use result::get_result_size;

crates/main/src/logger.rs

@@ -42,6 +42,14 @@
 //! [`WasmLogger`]: struct.WasmLogger.html
 //! [`log`]: https://docs.rs/log
 
+use log::Level as LogLevel;
+
+/// By default, logger will be initialized with log level from this environment variable.
+pub const WASM_LOG_ENV_NAME: &'static str = "WASM_LOG";
+
+/// If WASM_LOG_ENV isn't set, then this level will be used as the default.
+const WASM_DEFAULT_LOG_LEVEL: LogLevel = LogLevel::Info;
+
 pub type TargetMap = std::collections::HashMap<&'static str, i64>;
 
 /// The Wasm Logger.
@@ -67,12 +75,19 @@ pub struct WasmLoggerBuilder {
 }
 
 impl WasmLoggerBuilder {
-    /// Initializes a builder of the global logger with log level set to `Level::Info`.
-    /// It is a initial method in this builder chain, please note, that logger wouldn't work without
-    /// subsequent build() call.
+    /// Initializes a builder of the global logger. Set log level based on the WASM_LOG environment variable if it set,
+    /// or [[WASM_DEFAULT_LOG_LEVEL]] otherwise. It is an initial method in this builder chain, please note,
+    /// that logger wouldn't work without subsequent build() call.
     pub fn new() -> Self {
+        use std::str::FromStr;
+
+        let log_level = std::env::var(WASM_LOG_ENV_NAME)
+            .map_or(WASM_DEFAULT_LOG_LEVEL, |log_level_str| {
+                LogLevel::from_str(&log_level_str).unwrap_or(WASM_DEFAULT_LOG_LEVEL)
+            });
+
         Self {
-            log_level: log::Level::Info,
+            log_level,
             target_map: <_>::default(),
         }
     }

src/lib.rs

@@ -55,7 +55,7 @@
 //!     pub fn curl_get(url: String) -> String;
 //! }
 //! ```
-#![doc(html_root_url = "https://docs.rs/fluence/0.2.9")]
+#![doc(html_root_url = "https://docs.rs/fluence/0.2.10")]
 #![deny(
     dead_code,
     nonstandard_style,