# CMSSW work pages: a git-backed log pipeline for GitHub Pages > The cms-sw/cms-sw.github.io repository is the documentation and integration log site for the CMSSW software framework. It uses a two-branch workflow and a log import script to turn JSON build results into a static site. **cms-sw/cms-sw.github.io** — Documentation for CMSSW - Repository: https://github.com/cms-sw/cms-sw.github.io - Stars: 25 · Forks: 59 - Language: JavaScript - License: not declared - Published: 2026-08-21 · Updated: 2026-08-21 · Language: en - Canonical page: https://hysenlabs.com/projects/cms-sw-cms-sw-github-io ## What this repository actually is This is not a software product. It is the publishing layer for CMSSW, the C++ software framework used by the CMS experiment at CERN. The repository holds documentation and, more importantly, a set of scripts that pull integration build logs from /afs, a distributed network filesystem, and commit them into git. The git repository then serves those logs as a static website through GitHub Pages. The README is short and direct: it describes the repository as "CMSSW work pages" and lists two purposes. One is actual documentation. The other is a scripted import of log files. The balance between those two is telling. The documentation part is thin in the README. The log import part gets the detailed instructions. That suggests the maintainers care more about the data pipeline than about prose. ## The problem it solves: publishing many similar JSON files Integration builds produce a large number of log files, usually in JSON format. Storing them in a traditional web server or a database adds operational overhead. The README argues that git is suitable for this because it compresses similar files extremely well. That is a specific claim, and it is plausible: JSON logs from repeated builds share structure and content, so delta compression works well. The repository's approach is to store those logs directly in the git history and let GitHub Pages serve them. This removes the need for a dedicated log server. The target user is a CMSSW integration manager or a developer who needs to inspect past build results. It is not for someone who wants a generic documentation site. ## How the log import works The README gives a concrete workflow. You clone the repository, run a script called process-logs with a --logdir flag pointing to the top-level log directory, then run make with a job count. The make command presumably generates the HTML pages or copies the JSON into a data directory. After that, you commit the data directory and push to master. The exact behavior of process-logs is not documented in the README. It is a script in the repository, but the README does not explain its internal steps. What is clear is that the pipeline is batch-oriented: you run it manually, not as a continuous service. The command sequence is: git clone, cd, ./process-logs --logdir , make -j 20, git commit data, git push. That is the entire data flow. The repository is the storage and serving layer, and the script is the ingestion layer. ## The two-branch contribution model The repository has two branches: master and code. User-submitted changes, meaning documentation edits or scripts, go to the code branch. Auto-generated data, such as the JSON files produced by the Cms Bot, goes directly to master. The README references a pull request issue as a reason for this split. The logic is that human changes need review, while machine-generated data does not. This is a sensible separation, but it creates a maintenance burden. Anyone contributing must remember which branch to target. The README does not specify how the merge from code to master happens, or who performs it. It says code "will then be merged" into master, but gives no command or schedule. That is a gap in the documentation. If you contribute, you need to ask the maintainers about the merge process. ## Getting it running: exact commands and constraints The README provides the full command sequence. You start with git clone cms-sw.github.com, which is a typo in the original: the repository is cms-sw.github.io, but the README writes .com. That is a real error in the documentation. After cloning, you run ./process-logs --logdir . The script expects a path to a top-level log directory, but the README does not describe the required internal structure. Then you run make -j 20. The -j flag sets parallel jobs, but the README does not say what the Makefile does. It likely builds the site from the imported data. Finally, you commit the data directory and push. Note that the README says to commit data, not the whole working tree. That implies other files, like generated HTML, are either ignored or also in data. The command set is minimal, but it assumes you have a compatible log directory and a working make environment. ## Limitations and failure modes The most obvious limitation is that this repository is tied to a specific log source: /afs. The README says the scripts import logs "sparse in /afs", which means the tooling is not portable to other filesystems or log formats. If your logs are not in JSON, or not in the expected directory layout, process-logs will likely fail. Another failure mode is git history bloat. The README claims git handles similar files well, but that assumes the logs are similar. If the logs diverge in content, the repository size will grow. Also, the README does not mention any cleanup or pruning strategy. Over time, the git history will accumulate every log file ever committed. That could make cloning slow. The two-branch model also has a risk: if the Cms Bot writes directly to master and a human accidentally pushes to master, the separation collapses. The README does not explain how to prevent that. ## An alternative approach: a dedicated log storage service A different way to solve the same problem is to use a dedicated log aggregation service, such as Elasticsearch with Kibana, or a simple object storage like S3 with a static site generator. The difference is fundamental. This repository uses git as the database, relying on compression and GitHub Pages for serving. A log service would index the logs, allowing full-text search and querying. The git approach gives you version history and a simple static site, but no search. You can only browse pre-generated pages. For CMSSW, where integration builds are frequent and logs need to be compared across runs, a searchable index might be more practical. However, the README does not discuss any such comparison. The choice of git is likely driven by the existing infrastructure: the CMS experiment already uses git and GitHub, so this fits. An alternative like Elasticsearch would require separate hosting and maintenance. ## Maintenance and license implications The README does not mention a license. The repository metadata shows "unknown" for the license. That is a concern for anyone wanting to reuse the scripts or the documentation. You cannot assume you have permission to copy or modify the code. The maintenance cost is moderate. The pipeline is simple: a script and a makefile. But the reliance on a specific log directory structure means that any change in the /afs layout requires updating process-logs. The README does not describe how to test the import, so verifying a change is hard. There are no release tags or version numbers, so you cannot track changes systematically. The last push is unknown, which suggests the repository may be dormant. If you adopt this, you are relying on a project that may not be actively maintained. The two-branch model adds a small but real overhead for contributors. ## Conclusion Adopt this repository if you maintain CMSSW integration builds and need a low-cost way to publish log files as a static site. Do not adopt it for general documentation: it is tied to a specific /afs log layout and a make-based build. Before using it, verify that your log files are JSON and that your directory structure matches what process-logs expects. Also confirm that your git history can tolerate many similar compressed files, as the README explicitly relies on git's compression. If you need a more generic static site generator, consider Jekyll or Hugo instead, but note that this repo's value is in its log import workflow, not its page rendering. ## FAQ ### What is CMS GitHub? The CMS work pages live in a repository named cms-sw.github.io, hosted on GitHub, and the pages are served through GitHub Pages. It holds the CMSSW documentation together with scripts that import log files sparse in /afs into the git repository. ### What does CMS stand for in coding? Nothing in this repository expands that acronym. The pages are titled CMSSW work pages, and the documents are named after their topics, such as build-release, managing-properties, cms_coding_rules and infrastructure pages, with no glossary section. ### Is GitHub Pages a CMS? What the repository states is narrower than that. GitHub Pages is the delivery mechanism used to serve integration builds results, with processed log files committed to the repository and published from the master branch. ## Sources - [Official README](https://github.com/cms-sw/cms-sw.github.io#readme) - [Project repository](https://github.com/cms-sw/cms-sw.github.io) - [README](https://github.com/cms-sw/cms-sw.github.io/blob/master/README.md) - [Releases](https://github.com/cms-sw/cms-sw.github.io/releases) --- Hysen Labs editorial analysis, written from the project's own repository and release notes. Cite the canonical page: https://hysenlabs.com/projects/cms-sw-cms-sw-github-io