This repository contains the code for the worker nodes to be run in conjunction with the master server. These worker nodes are responsible for pulling down a specified repository, requesting work from the master server, computing the cyclomatic complexity of the file specified by the master server and returning that value to the master server.
Note node_modules has latest version of escomplex. That package seems to no longer be maintained on NPM but has a much newer version on github.
The worker's run a tiny REST API written in Node using Express in order to communicate with the master server.
The API exposes two endpoints: GET /ping and POST /job. They use the node-git library for cloning remote repositories and interacting with them locally. They also use this fork of escomplex in order to calculate the cyclomatic complexity of files.
This endpoint is simply used as a heartbeat sensor so that the master server knows if this worker is currently up.
Upon receipt of this ping, the worker simply responds with 200 OK.
The master server makes a POST request to the workers with a body containing a repoHash, repoName and repoOwner.
The worker then clones the remote repository (using node-git) into a local temporary directory (the impact of this design choice is discussed here).
Once the repository is cloned, the worker then requests work from the master server in the getWork() function.
This function makes a GET /work request to the master server who will in turn respond with either a {finished: true} indicating there is no more work, or a {repoHash, commitSha, file} indicating that the file contained in commit commitSha of repo repoHash must be processed.
At this point the worker proceeds to compute the cyclomatic complexity of said file.
Upon completion, the worker makes a POST /cyclomatic request to the master containing {repoHash, commitSha, file, cyclomatic} allowing this result to find its home.
Finally another call to getWork() is made and the process repeats.