promql-langserver

README

promql-lsp

Implementation of the Language Server Protocol for PromQL.

Roadmap

• Connect to IDEs and text editors over
  • Stdio
  • Websocket
  • HTTP
• Sync document content with the client
• Support plain PromQL queries
• Support queries inside yaml files (e.g. alertmanager configuration)
• Connect to a prometheus instance to get label and metric data
• Show error messages for incorrect queries in the client
• Show documentation on hover
  • Type information
  • Function documentation
  • Aggregator documentation
  • Keyword documentation
  • Metric and label help strings from a prometheus instance
• Completion
  • Functions
  • Metrics
  • Recording Rules
  • Aggregators
  • Labels
  • Label Values
  • Context sensitive, i.e respecting function argument types
• Signature information for functions (while typing)
• (Linting)
• (Formatting)

Some Screenshots

Completion in VS Code

Metric metadata from a Prometheus Server

Viewing documentation right from your editor

Vim and other editors are supported, too

Using the Language Server

A Language Server on its own is not very useful. You need some Language Client to use it with.

The following Language Clients have been tested with this language server. More will be added in the future.

Feel free to reach out if you want to use it with another Editor/Tool.

VS Code

There exists a VS Code extension based on this language server: https://github.com/slrtbtfs/vscode-prometheus

It is used as the main test platform for this language server.

Since it isn't published on the Extensions Marketplace yet, you'll have to follow the somewhat more complicated installation steps described in the README there.

(Neo)Vim

With Vim, currently only PromQL queries inside YAML files work without additional support. Generally the experience with Vim is more buggy than with VS Code.

Setup

1. Install the YouCompleteMe Plugin.

2. Put the configuration following configuration file for the language server in .vim/promql-lsp.yaml.

    # Change this adress to the address of the prometheus server you want to use for metadata
    prometheus_url: http://localhost:9090
    rpc_trace: text
   

3. Add the following to your .vimrc

    let g:ycm_language_server = [
      \   { 'name': 'promql',
      \     'filetypes': [ 'yaml' ],
      \     'cmdline': [ 'promql-langserver', '--config-file', expand('~/.vim/promql-lsp.yaml')]
      \   },
      \ ]
   

Debugging

The Vim command :YcmDebugInfo gives status information and points to logfiles.

Sublime Text 3

1. Install package LSP, LSP-promql via Package Control.
2. Follow the installation instruction.