Add a new metadata.Metadata proto separate from config to keep track of things last binary version.

crates/build/src/lib.rs

@@ -20,6 +20,7 @@ pub fn build_protos(proto_path: impl AsRef<Path>) -> Result<()> {
   let proto_files = vec![
     PathBuf::from(format!("{path}/config.proto")),
     PathBuf::from(format!("{path}/config_api.proto")),
+    PathBuf::from(format!("{path}/metadata.proto")),
     PathBuf::from(format!("{path}/vault.proto")),
   ];
 

crates/core/build.rs

@@ -4,6 +4,7 @@ fn main() -> std::io::Result<()> {
   trailbase_build::init_env_logger();
 
   println!("cargo::rerun-if-changed=migrations");
+  println!("cargo::rerun-if-changed=proto");
 
   trailbase_build::setup_version_info!();
   trailbase_build::build_protos("./proto")?;

crates/core/proto/metadata.proto

@@ -0,0 +1,9 @@
+syntax = "proto2";
+
+package metadata;
+
+message Metadata {
+  /// Last executed version of the `trail` binary. Can be used to detect
+  /// and react to binary changes across runs.
+  optional string last_executed_version = 1;
+}

crates/core/src/lib.rs

@@ -6,6 +6,7 @@ pub mod app_state;
 pub mod config;
 pub mod constants;
 pub mod logging;
+pub mod metadata;
 pub mod records;
 pub mod util;
 

crates/core/src/metadata.rs

@@ -0,0 +1,74 @@
+use log::*;
+use tokio::fs;
+
+use crate::config::ConfigError;
+use crate::data_dir::DataDir;
+
+pub mod proto {
+  use lazy_static::lazy_static;
+  use prost_reflect::text_format::FormatOptions;
+  use prost_reflect::{DynamicMessage, MessageDescriptor, ReflectMessage};
+
+  use crate::DESCRIPTOR_POOL;
+  use crate::config::ConfigError;
+
+  include!(concat!(env!("OUT_DIR"), "/metadata.rs"));
+
+  lazy_static! {
+    static ref METADATA_DESCRIPTOR: MessageDescriptor = DESCRIPTOR_POOL
+      .get_message_by_name("metadata.Metadata")
+      .expect("infallible");
+  }
+
+  impl Metadata {
+    pub fn new_with_custom_defaults() -> Self {
+      let version_info = trailbase_build::get_version_info!();
+      return Self {
+        last_executed_version: version_info.version_tag,
+      };
+    }
+
+    pub fn from_text(text: &str) -> Result<Self, ConfigError> {
+      let dyn_config = DynamicMessage::parse_text_format(METADATA_DESCRIPTOR.clone(), text)?;
+      return Ok(dyn_config.transcode_to::<Self>()?);
+    }
+
+    pub fn to_text(&self) -> Result<String, ConfigError> {
+      const PREFACE: &str = "# Auto-generated metadata.Metadata textproto";
+
+      let text: String = self
+        .transcode_to_dynamic()
+        .to_text_format_with_options(&FormatOptions::new().pretty(true).expand_any(true));
+
+      return Ok(format!("{PREFACE}\n{text}"));
+    }
+  }
+}
+
+pub async fn load_or_init_metadata_textproto(
+  data_dir: &DataDir,
+) -> Result<proto::Metadata, ConfigError> {
+  let metadata_path = data_dir.config_path().join(METADATA_FILENAME);
+
+  let config: proto::Metadata = match fs::read_to_string(&metadata_path).await {
+    Ok(contents) => proto::Metadata::from_text(&contents)?,
+    Err(err) => match err.kind() {
+      std::io::ErrorKind::NotFound => {
+        warn!("Falling back to default config: {err}");
+        let config = proto::Metadata::new_with_custom_defaults();
+
+        debug!("Writing metadata: {metadata_path:?}");
+        fs::write(&metadata_path, config.to_text()?.as_bytes()).await?;
+
+        config
+      }
+      _ => {
+        return Err(err.into());
+      }
+    },
+  };
+
+  return Ok(config);
+}
+
+const METADATA_FILENAME: &str = "metadata.textproto";

crates/core/src/server/init.rs

@@ -6,6 +6,7 @@ use crate::app_state::{AppState, AppStateArgs, build_objectstore};
 use crate::auth::jwt::{JwtHelper, JwtHelperError};
 use crate::config::load_or_init_config_textproto;
 use crate::constants::USER_TABLE;
+use crate::metadata::load_or_init_metadata_textproto;
 use crate::rand::generate_random_string;
 use crate::schema_metadata::SchemaMetadataCache;
 use crate::server::DataDir;
@@ -90,6 +91,8 @@ pub async fn init_app_state(args: InitArgs) -> Result<(bool, AppState), InitErro
   // Read config or write default one.
   let config = load_or_init_config_textproto(&args.data_dir, &schema_metadata).await?;
 
+  let _metadata = load_or_init_metadata_textproto(&args.data_dir).await?;
+
   debug!("Initializing JSON schemas from config");
   trailbase_schema::registry::set_user_schemas(
     config