FF-3593 feat(ruby): allow configuring log level from config (#72)

* Set default log level to info

* Fix checksum in cargo.lock

* Move logger initialization

* Bump ruby version

* FF-3593 feat(ruby): Allow overriding log level

* FF-3593 docs(ruby): add documentation on logging

---------

Co-authored-by: Oleksii Shmalko <[email protected]>

Author: sameerank

ruby-sdk/Cargo.lock

@@ -1,7 +1,7 @@
 PATH
   remote: .
   specs:
-    eppo-server-sdk (3.2.8)
+    eppo-server-sdk (3.3.0)
       rb_sys (~> 0.9.102)
 
 GEM

ruby-sdk/Gemfile.lock

@@ -7,6 +7,23 @@ Refer to our [SDK documentation](https://docs.geteppo.com/feature-flags/sdks/rub
 ## Supported Ruby Versions
 This version of the SDK is compatible with Ruby 3.0.6 and above.
 
+## Logging
+
+Ruby SDK uses [`env_logger`](https://docs.rs/env_logger/) for logging.
+
+Starting from version 3.3.0, the log level can be configured via `EPPO_LOG` environment variable using one of the following values:
+- `off`
+- `error`
+- `warn`
+- `info` (default)
+- `debug`
+- `trace`
+
+Alternatively, it can be configured using `log_level` parameter for `EppoClient::Config` constructor:
+```ruby
+config = EppoClient::Config.new("sdk-key", log_level: "debug")
+```
+
 # Contributing
 
 ## Testing with local version of `eppo_core`

ruby-sdk/README.md

@@ -1,7 +1,7 @@
 [package]
 name = "eppo_client"
 # TODO: this version and lib/eppo_client/version.rb should be in sync
-version = "3.2.8"
+version = "3.3.0"
 edition = "2021"
 license = "MIT"
 publish = false

ruby-sdk/ext/eppo_client/Cargo.toml

@@ -1,4 +1,4 @@
-use std::{cell::RefCell, sync::Arc, time::Duration};
+use std::{cell::RefCell, str::FromStr, sync::Arc, time::Duration};
 
 use eppo_core::{
     configuration_fetcher::{ConfigurationFetcher, ConfigurationFetcherConfig},
@@ -19,6 +19,7 @@ pub struct Config {
     base_url: String,
     poll_interval: Option<Duration>,
     poll_jitter: Duration,
+    log_level: Option<log::LevelFilter>,
 }
 
 impl TryConvert for Config {
@@ -29,11 +30,22 @@ impl TryConvert for Config {
         let poll_interval_seconds =
             Option::<u64>::try_convert(val.funcall("poll_interval_seconds", ())?)?;
         let poll_jitter_seconds = u64::try_convert(val.funcall("poll_jitter_seconds", ())?)?;
+
+        let log_level = {
+            let s = Option::<String>::try_convert(val.funcall("log_level", ())?)?;
+            s.map(|s| {
+                log::LevelFilter::from_str(&s)
+                    .map_err(|err| Error::new(exception::runtime_error(), err.to_string()))
+            })
+            .transpose()?
+        };
+
         Ok(Config {
             api_key,
             base_url,
             poll_interval: poll_interval_seconds.map(Duration::from_secs),
             poll_jitter: Duration::from_secs(poll_jitter_seconds),
+            log_level,
         })
     }
 }
@@ -52,6 +64,23 @@ pub struct Client {
 
 impl Client {
     pub fn new(config: Config) -> Client {
+        // Initialize logger
+        {
+            let mut builder = env_logger::Builder::from_env(
+                env_logger::Env::new()
+                    .filter_or("EPPO_LOG", "eppo=info")
+                    .write_style("EPPO_LOG_STYLE"),
+            );
+
+            if let Some(log_level) = config.log_level {
+                builder.filter_module("eppo", log_level);
+            }
+
+            // Logger can only be set once, so we ignore the initialization error here if client is
+            // re-initialized.
+            let _ = builder.try_init();
+        };
+
         let configuration_store = Arc::new(ConfigurationStore::new());
 
         let poller_thread = if let Some(poll_interval) = config.poll_interval {

ruby-sdk/ext/eppo_client/src/client.rs

@@ -14,8 +14,6 @@ pub(crate) const SDK_METADATA: SdkMetadata = SdkMetadata {
 
 #[magnus::init]
 fn init(ruby: &Ruby) -> Result<(), Error> {
-    env_logger::Builder::from_env(env_logger::Env::new().default_filter_or("eppo=debug")).init();
-
     let eppo_client = ruby.define_module("EppoClient")?;
     let core = eppo_client.define_module("Core")?;
 

ruby-sdk/ext/eppo_client/src/lib.rs

@@ -6,14 +6,15 @@
 module EppoClient
   # The class for configuring the Eppo client singleton
   class Config
-    attr_reader :api_key, :assignment_logger, :base_url, :poll_interval_seconds, :poll_jitter_seconds
+    attr_reader :api_key, :assignment_logger, :base_url, :poll_interval_seconds, :poll_jitter_seconds, :log_level
 
-    def initialize(api_key, assignment_logger: AssignmentLogger.new, base_url: EppoClient::Core::DEFAULT_BASE_URL, poll_interval_seconds: EppoClient::Core::DEFAULT_POLL_INTERVAL_SECONDS, poll_jitter_seconds: EppoClient::Core::DEFAULT_POLL_JITTER_SECONDS, initial_configuration: nil)
+    def initialize(api_key, assignment_logger: AssignmentLogger.new, base_url: EppoClient::Core::DEFAULT_BASE_URL, poll_interval_seconds: EppoClient::Core::DEFAULT_POLL_INTERVAL_SECONDS, poll_jitter_seconds: EppoClient::Core::DEFAULT_POLL_JITTER_SECONDS, initial_configuration: nil, log_level: nil)
       @api_key = api_key
       @assignment_logger = assignment_logger
       @base_url = base_url
       @poll_interval_seconds = poll_interval_seconds
       @poll_jitter_seconds = poll_jitter_seconds
+      @log_level = log_level
     end
 
     def validate

ruby-sdk/lib/eppo_client/config.rb

@@ -2,5 +2,5 @@
 
 # TODO: this version and ext/eppo_client/Cargo.toml should be in sync
 module EppoClient
-  VERSION = "3.2.8"
+  VERSION = "3.3.0"
 end