feat: add support for RDB current file size metric

[akshaykumar-vijapur]

Test result

# HELP redis_rdb_current_size_bytes Current RDB file size in bytes
# TYPE redis_rdb_current_size_bytes gauge
redis_rdb_current_size_bytes 188

All RDB-related Metrics

curl -s http://localhost:9122/metrics | grep -A 1 "redis_rdb"

Output:

# HELP redis_rdb_bgsave_in_progress rdb_bgsave_in_progress metric
# TYPE redis_rdb_bgsave_in_progress gauge
redis_rdb_bgsave_in_progress 0

# HELP redis_rdb_changes_since_last_save rdb_changes_since_last_save metric
# TYPE redis_rdb_changes_since_last_save gauge
redis_rdb_changes_since_last_save 0

# HELP redis_rdb_current_bgsave_duration_sec rdb_current_bgsave_duration_sec metric
# TYPE redis_rdb_current_bgsave_duration_sec gauge
redis_rdb_current_bgsave_duration_sec -1

# HELP redis_rdb_current_size_bytes Current RDB file size in bytes
# TYPE redis_rdb_current_size_bytes gauge
redis_rdb_current_size_bytes 188

# HELP redis_rdb_last_bgsave_duration_sec rdb_last_bgsave_duration_sec metric
# TYPE redis_rdb_last_bgsave_duration_sec gauge
redis_rdb_last_bgsave_duration_sec 0

# HELP redis_rdb_last_bgsave_status rdb_last_bgsave_status metric
# TYPE redis_rdb_last_bgsave_status gauge
redis_rdb_last_bgsave_status 1

# HELP redis_rdb_last_cow_size_bytes rdb_last_cow_size_bytes metric
# TYPE redis_rdb_last_cow_size_bytes gauge
redis_rdb_last_cow_size_bytes 385024

closes #1093

[oliver006]

This is great, thanks for opening this PR!

I'll give it a more thorough review later.

[codecov]

Codecov Report

❌ Patch coverage is 75.47170% with 13 lines in your changes missing coverage. Please review.
✅ Project coverage is 81.75%. Comparing base (d7bb38f) to head (5b57f63).
⚠️ Report is 1 commits behind head on master.

Files with missing lines	Patch %	Lines
exporter/rdb.go	75.55%	9 Missing and 2 partials ⚠️
main.go	0.00%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1095      +/-   ##
==========================================
- Coverage   81.88%   81.75%   -0.14%     
==========================================
  Files          20       21       +1     
  Lines        2700     2752      +52     
==========================================
+ Hits         2211     2250      +39     
- Misses        370      381      +11     
- Partials      119      121       +2     

☔ View full report in Codecov by Sentry.
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[oliver006]

Thanks for the PR - this feature is useful.
I left a bunch of comments that need addressing before we can move forward here.

// Made with Bob

It's ok to submit PRs with AI-generated code, I use AI myself all the time.

But I'd still expect a higher bar for code quality and expect you to review your own code before submitting the PR.
And/or use a better AI model.

[coveralls]

Coverage Report for CI Build 23999617636

Warning

Build has drifted: This PR's base is out of sync with its target branch, so coverage data may include unrelated changes.
Quick fix: rebase this PR. Learn more →

Coverage decreased (-0.09%) to 85.577%

Details

• Coverage decreased (-0.09%) from the base build.
• Patch coverage: 12 uncovered changes across 2 files (52 of 64 lines covered, 81.25%).
• No coverage regressions found.

Uncovered Changes

File	Changed	Covered	%
exporter/rdb.go	55	45	81.82%
main.go	2	0	0.0%

Coverage Regressions

No coverage regressions found.

---

Coverage Stats

Relevant Lines:	3321
Covered Lines:	2842
Line Coverage:	85.58%
Coverage Strength:	13887.6 hits per line

---

💛 - Coveralls

[akshaykumar-vijapur]

@oliver006 Pls review and check.

[akshaykumar-vijapur]

@oliver006 Pls check as we need this metrics in our env

[akshaykumar-vijapur]

@oliver006 pls review

[akshaykumar-vijapur]

@oliver006 pls review

[akshaykumar-vijapur]

##  End-to-End Test (Inside Container)

### Setup:
```bash
# Start Redis container with exposed ports
docker run -d --name redis-e2e-final -p 6381:6379 -p 9125:9125 redis:latest

# Create test data and RDB file
docker exec redis-e2e-final redis-cli SET key1 "value1"
docker exec redis-e2e-final redis-cli SET key2 "value2"
docker exec redis-e2e-final redis-cli BGSAVE
sleep 2

Output:

OK
OK
Background saving started

Verify RDB File:

docker exec redis-e2e-final ls -lh /data/dump.rdb

Output:

-rw-------. 1 redis redis 119 Apr  5 10:30 /data/dump.rdb

RDB File Size: 119 bytes

Deploy Exporter Inside Container:

# Copy linux binary to container
docker cp ./redis_exporter_linux redis-e2e-final:/usr/local/bin/redis_exporter
docker exec redis-e2e-final chmod +x /usr/local/bin/redis_exporter

# Start exporter with RDB metric enabled
docker exec -d redis-e2e-final /usr/local/bin/redis_exporter \
  --redis.addr=redis://localhost:6379 \
  --include-rdb-file-size-metric \
  --web.listen-address=:9125 \
  --log-format=txt

sleep 5

Fetch Metrics:

curl -s http://localhost:9125/metrics | grep -B1 -A1 "rdb_current_size_bytes"

Output:

redis_rdb_current_bgsave_duration_sec -1
# HELP redis_rdb_current_size_bytes Current RDB file size in bytes
# TYPE redis_rdb_current_size_bytes gauge
redis_rdb_current_size_bytes 119
# HELP redis_rdb_last_bgsave_duration_sec rdb_last_bgsave_duration_sec metric

Verification:

docker exec redis-e2e-final stat -c %s /data/dump.rdb

Output:

Expected file size: 119
Metric value:       119 bytes

Result: Metric accurately reports RDB file size

[oliver006]

remove the extra len(config) > 0 check here - extractRdbFileSizeMetric() handles that

[oliver006]

instead of the extra variable, call extractRdbFileSizeMetric() right up here, after line 839

[oliver006]

I just simplified the config extraction anfd it's using a ma[string]string now which should make this code a lot simpler

#1109

for instance,m you don't need to iterate over the config map any longer but can simply look up filename and directory.

Please rebase and then use the config map.