Extract crates_io_heroku crate with commit() fns

Cargo.toml

@@ -74,6 +74,7 @@ crates_io_diesel_helpers = { path = "crates/crates_io_diesel_helpers" }
 crates_io_docs_rs = { path = "crates/crates_io_docs_rs" }
 crates_io_env_vars = { path = "crates/crates_io_env_vars" }
 crates_io_github = { path = "crates/crates_io_github" }
+crates_io_heroku = { path = "crates/crates_io_heroku" }
 crates_io_index = { path = "crates/crates_io_index" }
 crates_io_linecount = { path = "crates/crates_io_linecount" }
 crates_io_markdown = { path = "crates/crates_io_markdown" }

crates/crates_io_database_dump/Cargo.toml

@@ -10,6 +10,7 @@ workspace = true
 [dependencies]
 anyhow = "=1.0.100"
 chrono = { version = "=0.4.42", default-features = false, features = ["clock", "serde"] }
+crates_io_heroku = { path = "../crates_io_heroku" }
 flate2 = "=1.1.5"
 minijinja = "=2.12.0"
 serde = { version = "=1.0.228", features = ["derive"] }

crates/crates_io_database_dump/src/lib.rs

@@ -70,8 +70,10 @@ impl DumpDirectory {
         }
         let metadata = Metadata {
             timestamp: &self.timestamp,
-            crates_io_commit: std::env::var("HEROKU_SLUG_COMMIT")
-                .unwrap_or_else(|_| "unknown".to_owned()),
+            crates_io_commit: crates_io_heroku::commit()
+                .ok()
+                .flatten()
+                .unwrap_or_else(|| "unknown".to_owned()),
         };
         let path = self.path().join("metadata.json");
         debug!(?path, "Writing metadata.json file…");

crates/crates_io_heroku/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "crates_io_heroku"
+version = "0.0.0"
+license = "MIT OR Apache-2.0"
+edition = "2024"
+
+[lints]
+workspace = true
+
+[dependencies]
+anyhow = "=1.0.100"
+crates_io_env_vars = { path = "../crates_io_env_vars" }

crates/crates_io_heroku/README.md

@@ -0,0 +1,11 @@
+# crates_io_heroku
+
+This package contains utilities for accessing Heroku-specific environment
+variables.
+
+When the `runtime-dyno-metadata` Heroku Labs feature is enabled, Heroku
+exposes application and environment information through environment variables.
+This crate provides convenient functions to access these values.
+
+For more information, see:
+<https://devcenter.heroku.com/articles/dyno-metadata>

crates/crates_io_heroku/src/lib.rs

@@ -0,0 +1,97 @@
+#![doc = include_str!("../README.md")]
+
+use crates_io_env_vars::var;
+
+/// Returns the Git SHA of the currently deployed commit.
+///
+/// This function tries `HEROKU_BUILD_COMMIT` first (the current standard),
+/// and falls back to `HEROKU_SLUG_COMMIT` (deprecated) if the former is not
+/// set. This provides compatibility with both old and new Heroku deployments.
+///
+/// Both environment variables are set by Heroku when the appropriate Labs
+/// features are enabled (`runtime-dyno-build-metadata` for `HEROKU_BUILD_COMMIT`,
+/// `runtime-dyno-metadata` for `HEROKU_SLUG_COMMIT`).
+///
+/// Returns `None` if neither variable is set (e.g., in local development).
+///
+/// See <https://devcenter.heroku.com/articles/dyno-metadata> for more
+/// information.
+///
+/// # Examples
+///
+/// ```
+/// use crates_io_heroku::commit;
+///
+/// if let Ok(Some(commit)) = commit() {
+///     println!("Running commit: {}", commit);
+/// } else {
+///     println!("Commit SHA unknown");
+/// }
+/// ```
+pub fn commit() -> anyhow::Result<Option<String>> {
+    // Try the current standard first
+    if let Some(commit) = build_commit()? {
+        return Ok(Some(commit));
+    }
+
+    // Fall back to the deprecated variable for backward compatibility
+    slug_commit()
+}
+
+/// Returns the Git SHA of the currently deployed commit.
+///
+/// This value comes from the `HEROKU_SLUG_COMMIT` environment variable,
+/// which is set by Heroku when the `runtime-dyno-metadata` Labs feature
+/// is enabled. If the variable is not set (e.g., in local development
+/// or when the feature is disabled), returns `None`.
+///
+/// Note: `HEROKU_SLUG_COMMIT` is deprecated by Heroku in favor of
+/// `HEROKU_BUILD_COMMIT`, but this function continues to use
+/// `HEROKU_SLUG_COMMIT` for backward compatibility with existing
+/// deployments.
+///
+/// See <https://devcenter.heroku.com/articles/dyno-metadata> for more
+/// information.
+///
+/// # Examples
+///
+/// ```
+/// use crates_io_heroku::slug_commit;
+///
+/// if let Ok(Some(commit)) = slug_commit() {
+///     println!("Running commit: {}", commit);
+/// } else {
+///     println!("Commit SHA unknown");
+/// }
+/// ```
+pub fn slug_commit() -> anyhow::Result<Option<String>> {
+    var("HEROKU_SLUG_COMMIT")
+}
+
+/// Returns the Git SHA of the currently deployed commit.
+///
+/// This value comes from the `HEROKU_BUILD_COMMIT` environment variable,
+/// which is set by Heroku when the `runtime-dyno-build-metadata` Labs
+/// feature is enabled. If the variable is not set (e.g., in local development
+/// or when the feature is disabled), returns `None`.
+///
+/// This is the recommended function to use, as `HEROKU_BUILD_COMMIT` is
+/// the current standard while `HEROKU_SLUG_COMMIT` is deprecated.
+///
+/// See <https://devcenter.heroku.com/articles/dyno-metadata> for more
+/// information.
+///
+/// # Examples
+///
+/// ```
+/// use crates_io_heroku::build_commit;
+///
+/// if let Ok(Some(commit)) = build_commit() {
+///     println!("Running commit: {}", commit);
+/// } else {
+///     println!("Commit SHA unknown");
+/// }
+/// ```
+pub fn build_commit() -> anyhow::Result<Option<String>> {
+    var("HEROKU_BUILD_COMMIT")
+}

src/config/sentry.rs

@@ -1,5 +1,6 @@
 use anyhow::Context;
 use crates_io_env_vars::{required_var, var, var_parsed};
+use crates_io_heroku::commit;
 use sentry::IntoDsn;
 use sentry::types::Dsn;
 
@@ -28,7 +29,7 @@ impl SentryConfig {
         Ok(Self {
             dsn,
             environment,
-            release: var("HEROKU_SLUG_COMMIT")?,
+            release: commit()?,
             traces_sample_rate: var_parsed("SENTRY_TRACES_SAMPLE_RATE")?.unwrap_or(0.0),
         })
     }

src/controllers/site_metadata.rs

@@ -1,6 +1,7 @@
 use crate::app::AppState;
 use axum::Json;
 use axum::response::IntoResponse;
+use crates_io_heroku::commit;
 use serde::Serialize;
 
 #[derive(Debug, Serialize, utoipa::ToSchema)]
@@ -33,7 +34,7 @@ pub struct MetadataResponse<'a> {
 pub async fn get_site_metadata(state: AppState) -> impl IntoResponse {
     let read_only = state.config.db.are_all_read_only();
 
-    let deployed_sha = dotenvy::var("HEROKU_SLUG_COMMIT");
+    let deployed_sha = commit().ok().flatten();
     let deployed_sha = deployed_sha.as_deref().unwrap_or("unknown");
 
     Json(MetadataResponse {

src/sentry/mod.rs

@@ -12,7 +12,8 @@ use tracing::warn;
 /// be set if a DSN is provided.
 ///
 /// `HEROKU_SLUG_COMMIT`, if present, will be used as the `release` property
-/// on all events.
+/// on all events. This environment variable is provided by Heroku when the
+/// `runtime-dyno-metadata` Labs feature is enabled.
 pub fn init() -> Option<ClientInitGuard> {
     let config = match SentryConfig::from_environment() {
         Ok(config) => config,