Percona Monitoring and Management (PMM) Documentation

Percona Monitoring and Management (PMM) is a database monitoring solution that is free and open-source.

This repo holds the source files for the official PMM technical documentation.

To contribute to that documentation, you can:

• report a general problem -- open a Jira issue.

• fix a problem yourself -- Use the Edit this page link to take you to the Markdown source file for that page. Make your changes (you'll have to fork the repo unless you're Percona staff) and submit a PR which we'll review and adjust where necessary before merging and publishing. If the changes are more than a few lines, you might want to build the website locally to see how it looks in context. That's what the rest of this README covers.

Introduction

We use MkDocs to convert Markdown files into a static HTML website (or PDF). This process is called building the documentation.

The documentation source files are in the docs directory. (Other files in this repo are explained in Directories and files.)

The two major PMM versions are kept in separate branches:

• main is for PMM 2.x (latest)

• 1.x is for PMM 1.x

Before you start, it helps to know what Git, Python and Docker are, what Markdown is and how to write it, and how to install and use those things on the command line. (If you don't, consider opening a Jira issue instead.)

Building the documentation

If you'd like to have a local copy of PMM documentation, or are thinking about contributing, it helps if you can build the documentation to see how it will look when published. The easiest way is to use Docker, as this avoids having to install MkDocs and its dependencies.

With Docker

1. Install Docker.

2. Clone this repository.

3. Change directory to pmm-doc.

4. Use our PMM documentation Docker image to build the documentation:

   docker run --rm -v $(pwd):/docs perconalab/pmm-doc-md mkdocs build

5. Find the site directory, open index.html in a browser to view the first page of documentation.

If you want to see how things look as you edit, MkDocs has a built-in server for live previewing. After (or instead of) building, run:

docker run --rm -v $(pwd):/docs -p 8000:8000 perconalab/pmm-doc-md mkdocs serve --dev-addr=0.0.0.0:8000

Wait until you see INFO - Start detecting changes then point your browser to http://0.0.0.0:8000.

Without Docker

If you don't use Docker, you must install MkDocs and all its dependencies.

1. Install Python.

2. Install MkDocs and required extensions:

   pip install -r requirements.txt

3. Build the site:

   mkdocs build

4. Open site/index.html

Or, to run the built-in web server:

mkdocs serve

View the site at http://0.0.0.0:8000

PDF

How to create a PDF version of the documentation.

1. (For Percona staff) If building for a release of PMM, edit mkdocs-base.yml and change:

   • The release number in plugins.with-pdf.output_path
   • The release number and date in plugins.with-pdf.cover_subtitle

2. Build

   • With Docker:

     docker run --rm -v $(pwd):/docs -e ENABLE_PDF_EXPORT=1 perconalab/pmm-doc-md mkdocs build -f mkdocs-pdf.yml

   • Without:

     ENABLE_PDF_EXPORT=1 mkdocs build -f mkdocs-pdf.yml

3. The PDF is in site/_pdf.

Directories and files

• mkdocs-percona.yml: MkDocs configuration file. Creates unthemed HTML for hosting on percona.com.

• mkdocs.yml: Default MkDocs configuration file. Creates (Material) themed HTML for hosting anywhere.

• mkdocs-pdf.yml: MkDocs configuration file. Creates themed PDF.

• docs:

  • *.md: Markdown files.

  • _images/*: Images, image resources, videos.

  • css: Styling.

  • js: JavaScript files.

• _resources:

  • bin

    • glossary.tsv: Export from a spreadsheet of glossary entries.

    • make_glossary.pl: Script to write Markdown page from glossary.tsv.

    • grafana-dashboards-descriptions.py: Script to extract dashboard descriptions from https://github.com/percona/grafana-dashboards/.

  • templates: Stylesheet for PDF output (used by mkdocs-with-pdf extension).

  • theme:

    • main.html: MkDocs template for HTML published on percona.com.

• requirements.txt: Python package dependencies.

• variables.yml: Values used throughout the Markdown, including the current PMM version/release number.

• .spelling: Words regarded as correct by mdspell (See Spelling and grammar.)

• .github:

  • workflows:

    • build.yml: Workflow specification for building the documentation via a GitHub action. (Uses mike which puts HTML in publish branch.)

• site: When building locally, directory where HTML is put.

Version switching

We use mike to build different versions of the documentation. Currently, only two are built, the latest PMM 1 and PMM 2 versions.

A GitHub actions workflow runs mike which in turn runs mkdocs. The HTML is committed and pushed to the publish branch. The whole branch is then copied (by an internal Percona Jenkins job) to our web server.

Image overlays

docs/using/interface.md uses an image of the home dashboard overlaid with numbered boxes to identify menu bars and control. This approach means the home dashboard image and its numbered version always look the same. You need only recreate the home page image in 1280x1280 format, then merge with the numbered overlay.

Here's how it's done.

• PMM_Home_Dashboard.jpg is created by pmm-screenshots-pw. If snapped by hand, it should be 1280x1280 pixels, to match the overlay image.

• PMM_Home_Dashboard_Overlay.png is exported from docs/_images/PMM_Home_Dashboard_Overlay.drawio using https://app.diagrams.net/.

  1. Go to https://app.diagrams.net/

  2. If it's your first time, select Device at the Save diagrams to: dialog

  3. Click Open existing diagram

  4. Navigate to pmm-doc/docs/_images and select PMM_Home_Dashboard_Overlay.drawio

  5. If the dashboard layout has changed, replace the Guide Layer with a new screenshot and adjust the elements on the Overlay layer as required (To show layers, click View --> Layers). Untick the Guide Layer so it is not exported.

  6. Click File --> Export as --> PNG

  7. In the Image settings dialog, use these settings:

     • Zoom: 100%, Border Width: 0

     • Size: Page (The page dimensions in inches should be as close to the base image as possible, i.e. 1280x1280)

     • Transparent Background: ON

     • Shadow: OFF

     • Grid: OFF

     • Include a copy of my diagram: OFF

  8. Click Export

  9. Click Device

  10. Navigate to pmm-doc/docs/_images and click PMM_Home_Dashboard_Overlay.png

  11. Click Save and overwrite the current file

The overlay image is merged with a copy of the latest home dashboard using composite, one of the ImageMagick tools.

composite docs/_images/PMM_Home_Dashboard_Overlay.png docs/_images/PMM_Home_Dashboard.jpg docs/_images/PMM_Home_Dashboard_Numbered.png

Spelling and grammar

The GitHub actions build job performs a basic spell check. (A grammar check is currently commented out in the actions file.) You can do these yourself on the command line if you have Node.js installed.

npm i markdown-spellcheck -g
mdspell --report --en-us --ignore-acronyms --ignore-numbers docs/<path to file>.md

To check all files:

mdspell --report --en-us --ignore-acronyms --ignore-numbers "docs/**/*.md"

Add any custom dictionary words to .spelling. The results of the spell check are printed, but the job ignores the return status.

Grammar is checked using write-good.

npm i write-good -g
write-good docs/<path to file>.md

To check all files:

write-good docs/**/*.md

Link checking

We're using the mkdocs-htmlproofer-plugin link checking plugin to detect broken URLs. It works well, but increases the build time significantly (by between 10 and 50 times longer).

The plugin is installed in our PMM documentation Docker image and by the GitHub action, but it is commented out in mkdocs.yml.

To enable it for local builds, uncomment the line with htmlproofer in the plugins section of mkdocs.yml and parse the build output for warnings.