There are three separate instances of process log APIs: embark logs, blockchain logs (when in standalone mode), and child process logs (storage, communication, blockchain, etc). Each one was repeating the implementation of creating a process log API endpoint. This commit centralises the API declaration by using the class `ProcessLogsApi`.
`ProcessLogsApi` is started for all three components mentioned above: blockchain (in standalone) in the `BlockchainListener` module, embark in the `EmbarkListener` module, and for all child processes in the `ProcessLauncher`.
These listeners have two functions:
1. Create the process logs API endpoints for `get` and `ws`, and
2. Ensure that all logs are logged through the `LogHandler`, which normalises the output of the log and ensures each log has a timestamp and id (used in the cockpit for log ordering).
Also, this commit moved the pipeline in to a module, so that the `embark` object could be passed to the `ProcessLogsApi` (to be used for registering API endpoints).
When running `embark blockchain` followed by `embark run` previously, logs generated in the standalone `embark blockchain` process were black boxed and not accessible to the main Embark process.
This is fixed by creating a client IPC connection in the `embark blockchain` process that connects to the IPC server connection running in `embark run`. The connection is made by way of polling `ipc.connect` and continues polling even after a connection is made in case `embark run` is killed and restarted without restarting `embark blockchain`.
`LogHandler` was introduced to extrapolate functionality used in `ProcessLauncher` that needed to also be used in the standalone blockchain process. It also caps the number of logs that are stored in memory per process by a constant value defined in `constants.json`.
A `blockchain_listener` was module was created (and run inside of `embark run`) that listens for logs emitted by the `embark blockchain` client IPC and runs them through the `LogHandler`. Additionally, this module registers the API endpoints needed to handle requests for blockchain process logs in the cockpit (which were 404’ing before).
# Conflicts:
# lib/modules/blockchain_process/blockchain.js