chore: /metrics endpoint (hash distribution & rehash counters) #47

zensgit · 2025-09-26T00:47:28Z

Adds /metrics endpoint with Prometheus text output:\n- jive_password_rehash_total counter\n- jive_password_hash_users{algo} gauges (2a,2b,2y,argon2id)\n\nNon-breaking; queries best-effort. All existing tests pass.

gemini-code-assist · 2025-09-26T00:47:38Z

Summary of Changes

Hello @zensgit, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances the jive-api by integrating a dedicated /metrics endpoint. This endpoint exposes crucial operational data in a Prometheus-friendly format, specifically focusing on password security metrics. It provides insights into the ongoing transition of password hashing algorithms and the current distribution of users across different hashing schemes, facilitating better monitoring and operational awareness without impacting existing functionality.

Highlights

New Metrics Endpoint: Introduces a new /metrics endpoint to the API, providing Prometheus-compatible output for monitoring.
Password Rehash Counter: Adds a jive_password_rehash_total counter to track the total number of successful bcrypt to argon2id password rehashes.
Password Hash Distribution Gauge: Includes a jive_password_hash_users gauge that reports the count of users for each password hash algorithm variant (bcrypt 2a, 2b, 2y, and argon2id).
Non-Breaking Changes: The changes are non-breaking, and all existing tests continue to pass, ensuring backward compatibility.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	`/gemini review`	Performs a code review for the current pull request in its current state.
Pull Request Summary	`/gemini summary`	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	`/gemini help`	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

Copilot

Pull Request Overview

This PR adds a Prometheus-compatible metrics endpoint to the Jive API service, exposing password hash distribution data and rehash counters for monitoring purposes.

Adds /metrics endpoint that returns Prometheus text format metrics
Tracks password hash algorithm distribution (bcrypt 2a/2b/2y, argon2id) and rehash counters
Implements best-effort querying with graceful fallback to zero values on database errors

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
jive-api/src/metrics.rs	New metrics handler implementing Prometheus text format output with password hash distribution and rehash counter metrics
jive-api/src/main.rs	Adds metrics module and routes `/metrics` endpoint to the metrics handler

_{Tip: Customize your code reviews with copilot-instructions.md. Create the file or learn how to get started.}

Copilot · 2025-09-26T00:47:59Z

jive-api/src/metrics.rs

+            row.try_get::<i64,_>("b2y").unwrap_or(0),
+            row.try_get::<i64,_>("a2id").unwrap_or(0),
+        )
+    } else { (0,0,0,0) };


[nitpick] The tuple lacks spacing between elements. Consider formatting as (0, 0, 0, 0) for better readability and consistency with Rust formatting conventions.

Suggested change

} else { (0,0,0,0) };

} else { (0, 0, 0, 0) };

Copilot · 2025-09-26T00:47:59Z

jive-api/src/metrics.rs

+    let (b2a, b2b, b2y, a2id) = if let Ok(row) = sqlx::query(
+        "SELECT \
+            COUNT(*) FILTER (WHERE password_hash LIKE '$2a$%') AS b2a,\
+            COUNT(*) FILTER (WHERE password_hash LIKE '$2b$%') AS b2b,\
+            COUNT(*) FILTER (WHERE password_hash LIKE '$2y$%') AS b2y,\
+            COUNT(*) FILTER (WHERE password_hash LIKE '$argon2id$%') AS a2id\
+         FROM users"
+    ).fetch_one(pool).await {
+        use sqlx::Row;
+        (
+            row.try_get::<i64,_>("b2a").unwrap_or(0),
+            row.try_get::<i64,_>("b2b").unwrap_or(0),
+            row.try_get::<i64,_>("b2y").unwrap_or(0),
+            row.try_get::<i64,_>("a2id").unwrap_or(0),
+        )
+    } else { (0,0,0,0) };


This query performs multiple LIKE operations on the same column. Consider using a single query with CASE statements or regular expressions for better performance: SELECT algo, COUNT(*) FROM (SELECT CASE WHEN password_hash LIKE '$2a$%' THEN 'b2a' WHEN password_hash LIKE '$2b$%' THEN 'b2b' ... END as algo FROM users) GROUP BY algo.

Suggested change

let (b2a, b2b, b2y, a2id) = if let Ok(row) = sqlx::query(

"SELECT \

COUNT(*) FILTER (WHERE password_hash LIKE '$2a$%') AS b2a,\

COUNT(*) FILTER (WHERE password_hash LIKE '$2b$%') AS b2b,\

COUNT(*) FILTER (WHERE password_hash LIKE '$2y$%') AS b2y,\

COUNT(*) FILTER (WHERE password_hash LIKE '$argon2id$%') AS a2id\

FROM users"

).fetch_one(pool).await {

use sqlx::Row;

(

row.try_get::<i64,_>("b2a").unwrap_or(0),

row.try_get::<i64,_>("b2b").unwrap_or(0),

row.try_get::<i64,_>("b2y").unwrap_or(0),

row.try_get::<i64,_>("a2id").unwrap_or(0),

)

} else { (0,0,0,0) };

let mut b2a = 0;

let mut b2b = 0;

let mut b2y = 0;

let mut a2id = 0;

if let Ok(rows) = sqlx::query(

"SELECT

CASE

WHEN password_hash LIKE '$2a$%' THEN 'b2a'

WHEN password_hash LIKE '$2b$%' THEN 'b2b'

WHEN password_hash LIKE '$2y$%' THEN 'b2y'

WHEN password_hash LIKE '$argon2id$%' THEN 'a2id'

ELSE 'other'

END AS algo,

COUNT(*) as count

FROM users

GROUP BY algo"

).fetch_all(pool).await {

use sqlx::Row;

for row in rows {

let algo: String = row.try_get("algo").unwrap_or_default();

let count: i64 = row.try_get("count").unwrap_or(0);

match algo.as_str() {

"b2a" => b2a = count,

"b2b" => b2b = count,

"b2y" => b2y = count,

"a2id" => a2id = count,

_ => {},

}

}

}

gemini-code-assist

Code Review

This pull request introduces a /metrics endpoint for Prometheus, exposing password hash distribution and rehash counts. The implementation is a good start for improving observability. My review includes a critical fix for potential panics in error handling, along with suggestions to improve maintainability by reducing code duplication and adding logging for silent failures. Addressing these points will make the new endpoint more robust and easier to maintain.

gemini-code-assist · 2025-09-26T00:49:04Z

jive-api/src/metrics.rs

+            row.try_get::<i64,_>("b2a").unwrap_or(0),
+            row.try_get::<i64,_>("b2b").unwrap_or(0),
+            row.try_get::<i64,_>("b2y").unwrap_or(0),
+            row.try_get::<i64,_>("a2id").unwrap_or(0),


unwrap_or() on a Result panics if the value is an Err, which would crash the request handler. To safely provide a default value, you should convert the Result to an Option with .ok() first, or use unwrap_or_else. This same issue exists in the duplicated code in main.rs's health_check function.

Suggested change

row.try_get::<i64,_>("b2a").unwrap_or(0),

row.try_get::<i64,_>("b2b").unwrap_or(0),

row.try_get::<i64,_>("b2y").unwrap_or(0),

row.try_get::<i64,_>("a2id").unwrap_or(0),

row.try_get::<i64,_>("b2a").ok().unwrap_or(0),

row.try_get::<i64,_>("b2b").ok().unwrap_or(0),

row.try_get::<i64,_>("b2y").ok().unwrap_or(0),

row.try_get::<i64,_>("a2id").ok().unwrap_or(0),

gemini-code-assist · 2025-09-26T00:49:04Z

jive-api/src/metrics.rs

+pub async fn metrics_handler(axum::extract::State(state): axum::extract::State<AppState>) -> impl IntoResponse {
+    let pool: &PgPool = &state.pool;
+    // Query hash distribution (best-effort)
+    let (b2a, b2b, b2y, a2id) = if let Ok(row) = sqlx::query(


This block of code for querying the password hash distribution (lines 9-24) is identical to the one in the health_check function in main.rs. Duplicating code makes maintenance harder and increases the chance of bugs (like an issue I've pointed out separately). Consider extracting this logic into a shared function, for example as a new method on AppState or in a database utility module, to improve maintainability.

gemini-code-assist · 2025-09-26T00:49:04Z

jive-api/src/metrics.rs

+            row.try_get::<i64,_>("b2y").unwrap_or(0),
+            row.try_get::<i64,_>("a2id").unwrap_or(0),
+        )
+    } else { (0,0,0,0) };


When the database query fails, the error is silently ignored, and the metrics default to 0. This can hide underlying database problems. It would be better to log a warning when the query fails.

Suggested change

} else { (0,0,0,0) };

} else { tracing::warn!("Failed to query password hash distribution for metrics"); (0,0,0,0) };

chore: add /metrics endpoint with password hash + rehash counters

961362c

Copilot AI review requested due to automatic review settings September 26, 2025 00:47

zensgit enabled auto-merge (squash) September 26, 2025 00:47

Copilot AI reviewed Sep 26, 2025

View reviewed changes

gemini-code-assist bot reviewed Sep 26, 2025

View reviewed changes

fix: rustfmt formatting

8a304c2

zensgit merged commit e6d55d6 into main Sep 26, 2025
10 checks passed

zensgit deleted the chore/metrics-endpoint branch September 26, 2025 01:10

gemini-code-assist bot mentioned this pull request Sep 26, 2025

docs/metrics: canonical hash metrics docs + consistency script #49

Merged

zensgit mentioned this pull request Oct 15, 2025

core db track 1 #91

Draft

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

chore: /metrics endpoint (hash distribution & rehash counters) #47

chore: /metrics endpoint (hash distribution & rehash counters) #47

Uh oh!

zensgit commented Sep 26, 2025

Uh oh!

gemini-code-assist bot commented Sep 26, 2025

Uh oh!

Copilot AI left a comment

Uh oh!

Copilot AI Sep 26, 2025

Uh oh!

Copilot AI Sep 26, 2025

Uh oh!

gemini-code-assist bot left a comment

Uh oh!

gemini-code-assist bot Sep 26, 2025

Uh oh!

gemini-code-assist bot Sep 26, 2025

Uh oh!

gemini-code-assist bot Sep 26, 2025

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant

-    let (b2a, b2b, b2y, a2id) = if let Ok(row) = sqlx::query(
-        "SELECT \
-            COUNT(*) FILTER (WHERE password_hash LIKE '$2a$%') AS b2a,\
-            COUNT(*) FILTER (WHERE password_hash LIKE '$2b$%') AS b2b,\
-            COUNT(*) FILTER (WHERE password_hash LIKE '$2y$%') AS b2y,\
-            COUNT(*) FILTER (WHERE password_hash LIKE '$argon2id$%') AS a2id\
-         FROM users"
-    ).fetch_one(pool).await {
-        use sqlx::Row;
-        (
-            row.try_get::<i64,_>("b2a").unwrap_or(0),
-            row.try_get::<i64,_>("b2b").unwrap_or(0),
-            row.try_get::<i64,_>("b2y").unwrap_or(0),
-            row.try_get::<i64,_>("a2id").unwrap_or(0),
-        )
-    } else { (0,0,0,0) };
+    let mut b2a = 0;
+    let mut b2b = 0;
+    let mut b2y = 0;
+    let mut a2id = 0;
+    if let Ok(rows) = sqlx::query(
+        "SELECT
+            CASE
+                WHEN password_hash LIKE '$2a$%' THEN 'b2a'
+                WHEN password_hash LIKE '$2b$%' THEN 'b2b'
+                WHEN password_hash LIKE '$2y$%' THEN 'b2y'
+                WHEN password_hash LIKE '$argon2id$%' THEN 'a2id'
+                ELSE 'other'
+            END AS algo,
+            COUNT(*) as count
+         FROM users
+         GROUP BY algo"
+    ).fetch_all(pool).await {
+        use sqlx::Row;
+        for row in rows {
+            let algo: String = row.try_get("algo").unwrap_or_default();
+            let count: i64 = row.try_get("count").unwrap_or(0);
+            match algo.as_str() {
+                "b2a" => b2a = count,
+                "b2b" => b2b = count,
+                "b2y" => b2y = count,
+                "a2id" => a2id = count,
+                _ => {},
+            }
+        }
+    }

	} else { (0,0,0,0) };
	} else { tracing::warn!("Failed to query password hash distribution for metrics"); (0,0,0,0) };

chore: /metrics endpoint (hash distribution & rehash counters) #47

chore: /metrics endpoint (hash distribution & rehash counters) #47

Uh oh!

Conversation

zensgit commented Sep 26, 2025

Uh oh!

gemini-code-assist bot commented Sep 26, 2025

Summary of Changes

Highlights

Footnotes

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull Request Overview

Reviewed Changes

Uh oh!

Copilot AI Sep 26, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Sep 26, 2025

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist bot left a comment

Choose a reason for hiding this comment

Code Review

Uh oh!

gemini-code-assist bot Sep 26, 2025

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist bot Sep 26, 2025

Choose a reason for hiding this comment

Uh oh!

gemini-code-assist bot Sep 26, 2025

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

1 participant