a0463f5501
Signed-off-by: Julius Volz <julius.volz@gmail.com>
5 KiB
Overview
The ui directory contains static files and templates used in the web UI. For
easier distribution they are compressed (c.f. Makefile) and statically compiled
into the Prometheus binary using the embed package.
During development it is more convenient to always use the files on disk to
directly see changes without recompiling.
To make this work, remove the builtinassets build tag in the flags entry
in .promu.yml, and then make build (or build Prometheus using
go build ./cmd/prometheus).
This will serve all files from your local filesystem. This is for development purposes only.
React-app
Introduction
This directory contains two generations of Prometheus' React-based web UI:
react-app: The old 2.x web UImantine-ui: The new 3.x web UI
Both UIs are built and compiled into Prometheus. The new UI is served by default, but a feature flag
(--enable-feature=old-ui) can be used to switch back to serving the old UI.
Then you have different npm packages located in the folder modules. These packages are supposed to be used by the
two React apps and also by others consumers (like Thanos).
While most of these applications / modules are part of the same npm workspace, the old UI in the react-app directory
has been separated out of the workspace setup, since its dependencies were too incompatible.
Pre-requisite
To be able to build either of the React applications, you need:
- npm >= v7
- node >= v20
Installing npm dependencies
The React UI depends on a large number of npm packages. These are not checked in, so you will
need to move to the directory web/ui and then download and install them locally via the npm package manager:
npm install
npm consults the package.json and package-lock.json files for dependencies to install. It creates a node_modules
directory with all installed dependencies.
NOTE: Do not run npm install in the react-app / mantine-ui folder or in any sub folder of the module directory.
Upgrading npm dependencies
As it is a monorepo, when upgrading a dependency, you have to upgrade it in every packages that composed this monorepo
(aka, in all sub folders of module and react-app / mantine-ui)
Then you have to run the command npm install in web/ui and not in a sub folder / sub package. It won't simply work.
Running a local development server
You can start a development server for the new React UI outside of a running Prometheus server by running:
npm start
(For the old UI, you will have to run the same command from the react-app subdirectory.)
This will open a browser window with the React app running on http://localhost:5173/. The page will reload if you make edits to the source code. You will also see any lint errors in the console.
NOTE: It will reload only if you change the code in mantine-ui folder. Any code changes in the folder module is
not considered by the command npm start. In order to see the changes in the react-app you will have to
run npm run build:module
Due to a "proxy": "http://localhost:9090" setting in the mantine-ui/vite.config.ts file, any API requests from the React UI are
proxied to localhost on port 9090 by the development server. This allows you to run a normal Prometheus server to
handle API requests, while iterating separately on the UI.
[browser] ----> [localhost:5173 (dev server)] --(proxy API requests)--> [localhost:9090 (Prometheus)]
Running tests
To run the test for the new React app and for all modules, you can simply run:
npm test
(For the old UI, you will have to run the same command from the react-app subdirectory.)
If you want to run the test only for a specific module, you need to go to the folder of the module and run
again npm test.
For example, in case you only want to run the test of the new React app, go to web/ui/mantine-ui and run npm test
To generate an HTML-based test coverage report, run:
CI=true npm test:coverage
This creates a coverage subdirectory with the generated report. Open coverage/lcov-report/index.html in the browser
to view it.
The CI=true environment variable prevents the tests from being run in interactive / watching mode.
See the Create React App documentation for more information about running tests.
Building the app for production
To build a production-optimized version of both React app versions to a static/{react-app,mantine-ui} subdirectory, run:
npm run build
NOTE: You will likely not need to do this directly. Instead, this is taken care of by the build target in the main
Prometheus Makefile when building the full binary.
Integration into Prometheus
To build a Prometheus binary that includes a compiled-in version of the production build of both React app versions, change to the root of the repository and run:
make build
This installs dependencies via npm, builds a production build of both React apps, and then finally compiles in all web assets into the Prometheus binary.