Getting Started

Step 1: Installing/Upgrading Breadlog

Note

Breadlog only supports Linux x86-64 targets with glibc 2.31+ at the moment.

Go to the list of Breadlog releases.
Download the Installer Archive for the release you want to install (probably the latest).
Install Breadlog by extracting the archive (you may need to sudo):
```
# tar -xz -C / -f breadlog-package-vX.Y.Z-linux_x86-64.tar.gz
```
Test your installation by running Breadlog:
```
$ breadlog --version
```

Step 2: Configuring a repository

Warning

Ensure your code is backed up (e.g. committed to a git repository) before running Breadlog.

Create a file called Breadlog.yaml in the root of your repository.
Set the file contents as follows:
```
---
source_dir: <RELATIVE SOURCE DIRECTORY>
rust:
  log_macros:
    - module: log
      name: info
    - module: log
      name: warn
    - module: log
      name: error
```
Replace <RELATIVE SOURCE DIRECTORY> above with the path to the source code you want Breadlog to analyse, relative to the repository root.

For example, if your code was in a directory called my_app/, then you would set source_dir to ./my_app.

This configuration assumes you’re using the Rust log crate for logging in your code.

Step 3: Running Breadlog for the first time

It’s good practice to run Breadlog in check mode before allowing it to modify your code. Check mode guarantees that Breadlog will not modify your code, but instead report on the modifications it would have made if it was in code generation mode.

Check mode can also be used to verify that there are no missing references in log statements across your codebase. This is particularly useful in CI pipelines. Breadlog’s exit code will be non-zero if it finds missing references in check mode.

All commands below are to be run from the repository root.

Run Breadlog in check mode:

$ breadlog -c ./Breadlog.yaml --check

You’ll see output similar to the following:

2023-11-21T10:34:26.943Z INFO [breadlog] [ref: 22] Reading configuration file: ./Breadlog.yaml
2023-11-21T10:34:26.943Z INFO [breadlog] [ref: 25] Configuration loaded!
2023-11-21T10:34:26.943Z INFO [breadlog] [ref: 27] Running in check mode
2023-11-21T10:34:26.945Z INFO [breadlog::codegen::generate] [ref: 15] Found 280 file(s)
...
2023-11-21T10:34:29.872Z INFO [breadlog::codegen::generate] [ref: 6] Total missing references in ././core/http/src/status.rs: 0
2023-11-21T10:34:29.880Z INFO [breadlog::codegen::generate] [ref: 6] Total missing references in ././core/http/src/lib.rs: 0
2023-11-21T10:34:29.921Z WARN [breadlog::codegen::generate] [ref: 5] Missing reference in file ././core/http/src/listener.rs, line 178, column 36
2023-11-21T10:34:29.921Z WARN [breadlog::codegen::generate] [ref: 5] Missing reference in file ././core/http/src/listener.rs, line 186, column 32
2023-11-21T10:34:29.921Z WARN [breadlog::codegen::generate] [ref: 5] Missing reference in file ././core/http/src/listener.rs, line 189, column 32
2023-11-21T10:34:29.921Z INFO [breadlog::codegen::generate] [ref: 6] Total missing references in ././core/http/src/listener.rs: 3
...
2023-11-21T10:34:34.987Z INFO [breadlog::codegen::generate] [ref: 7] Total missing references (all files): 46
2023-11-21T10:34:34.987Z ERROR [breadlog] [ref: 28] Failed: One or more missing references were found

The locations Breadlog reports missing references are where it will insert references when run in code generation mode (when you omit the --check flag).

Once you’re happy with the output, you can run Breadlog in code generation mode (without the --check flag). This will modify your code, inserting references in log messages where they are found to be missing:
```
$ breadlog -c ./Breadlog.yaml
```
Assuming you’re happy with the changes Breadlog has made, commit them to your repository along with the Breadlog.yaml and Breadlog.lock files.

Next steps

Read the other sections in this user guide (it’s not very long!) to learn more about configuration options, using Breadlog from CI pipelines, known limitations and more.