Add support for json logging. (#138)

This introduces a new _optional_ config option `log_format` which can be
either `"pretty"` (the default) or `"json"`.

Cargo.toml

@@ -25,6 +25,7 @@ bytes = "1.0"
 time = "0.3"
 tracing-subscriber = { version = "0.3.17", features = [
     "fmt",
+    "json",
     "std",
     "env-filter",
 ] }

config/Settings.example.toml

@@ -1,4 +1,5 @@
 log_level = "info"
+log_format = "pretty"
 network = "public-testnet-15"
 
 [database]

contrib/helm/indexer-values.yaml

@@ -64,6 +64,7 @@ configMap:
     settings:
       Settings.toml: |
         log_level = "info"
+        log_format = "json"
         network = "public-testnet-14"
     
         [database]

contrib/helm/server-values.yaml

@@ -65,6 +65,7 @@ configMap:
     settings:
       Settings.toml: |
         log_level = "info"
+        log_format = "json"
         network = "public-testnet-14"
         
         [database]

docs/03-indexer.md

@@ -8,8 +8,9 @@ The indexer must have the following configuration:
 
 Settings.toml
 ```toml
-# Level of logging in the indexer
+# Level and format of logging in the indexer
 log_level = "info"
+log_format = "pretty" # optional; either "pretty" or "json"
 network = "public-testnet-15" # IMPORANT! Do not use `.` just put the name of the network and don't have the hash (e.g 'shielded-expedition.b40d8e9055' becomes 'shielded-expedition')
 
 # Connection information for the PostgreSQL database

docs/04-server.md

@@ -8,6 +8,7 @@ Settings.toml
 
 ```toml
 log_level = "info"
+log_format = "pretty" # optional; either "pretty" or "json"
 network = "public-testnet-15" # IMPORANT! Do not use `.` just put the name of the network and don't have the hash (e.g 'shielded-expedition.b40d8e9055' becomes 'shielded-expedition')
 
 # Connection information for the PostgreSQL database

src/config.rs

@@ -20,6 +20,8 @@ pub const PROMETHEUS_PORT: u16 = 9000;
 
 pub const DEFAULT_NETWORK: &str = "public-testnet-15";
 
+pub const DEFAULT_LOG_FORMAT: &str = "pretty";
+
 #[derive(Debug, Deserialize)]
 pub struct IndexerConfig {
     pub tendermint_addr: String,
@@ -125,10 +127,20 @@ impl Default for DatabaseConfig {
     }
 }
 
+#[derive(Debug, Default, Deserialize, Clone, clap::ValueEnum)]
+#[serde(rename_all = "kebab-case")]
+pub enum LogFormat {
+    Json,
+    #[default]
+    Pretty,
+}
+
 #[derive(Debug, Deserialize, clap::Parser)]
 pub struct CliSettings {
     #[clap(long, env, default_value = "")]
     pub log_level: String,
+    #[clap(long, env, default_value = DEFAULT_LOG_FORMAT)]
+    pub log_format: LogFormat,
     #[clap(long, env, default_value = DEFAULT_NETWORK)]
     pub network: String,
     #[clap(long, env, default_value = SERVER_ADDR)]
@@ -166,6 +178,8 @@ pub struct CliSettings {
 #[derive(Debug, Deserialize)]
 pub struct Settings {
     pub log_level: String,
+    #[serde(default)]
+    pub log_format: LogFormat,
     pub network: String,
     pub database: DatabaseConfig,
     pub server: ServerConfig,
@@ -178,6 +192,7 @@ impl Default for Settings {
     fn default() -> Self {
         Self {
             log_level: Default::default(),
+            log_format: Default::default(),
             network: DEFAULT_NETWORK.to_string(),
             database: Default::default(),
             server: Default::default(),
@@ -192,6 +207,7 @@ impl From<CliSettings> for Settings {
     fn from(value: CliSettings) -> Self {
         Self {
             log_level: value.log_level,
+            log_format: value.log_format,
             network: value.network,
             database: DatabaseConfig {
                 host: value.database_host,

src/lib.rs

@@ -8,7 +8,9 @@ pub mod tables;
 mod telemetry;
 pub mod utils;
 
-pub use crate::config::{IndexerConfig, JaegerConfig, PrometheusConfig, ServerConfig, Settings};
+pub use crate::config::{
+    IndexerConfig, JaegerConfig, LogFormat, PrometheusConfig, ServerConfig, Settings,
+};
 pub use database::Database;
 pub use error::Error;
 pub use indexer::start_indexing;

src/telemetry.rs

@@ -3,7 +3,7 @@ use tracing_subscriber::Layer;
 
 use tracing_subscriber::{filter::filter_fn, layer::SubscriberExt, EnvFilter, Registry};
 
-use crate::{JaegerConfig, Settings};
+use crate::{JaegerConfig, LogFormat, Settings};
 use opentelemetry_api::global;
 
 /// Setup looging this includes a fmt::layer and jaeger(if enable)
@@ -25,8 +25,11 @@ pub fn get_subscriber(cfg: &Settings) -> impl Subscriber + Send + Sync {
     let env_filter =
         EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new(&cfg.log_level));
 
-    // send any logs to stdout
-    let std_out = tracing_subscriber::fmt::layer().pretty();
+    // send logs to stdout in the configured format
+    let (json, pretty) = match cfg.log_format {
+        LogFormat::Json => (Some(tracing_subscriber::fmt::layer().json()), None),
+        LogFormat::Pretty => (None, Some(tracing_subscriber::fmt::layer().pretty())),
+    };
 
     // check if jaeger telemetry is enable and configure it accordingly
     let jaeger_cfg = cfg.jaeger_config();
@@ -37,7 +40,8 @@ pub fn get_subscriber(cfg: &Settings) -> impl Subscriber + Send + Sync {
 
     Registry::default()
         .with(env_filter)
-        .with(std_out)
+        .with(json)
+        .with(pretty)
         .with(jaeger)
 }