forgebuild looks up your ~/.forgebuild/ folder to find tasks to run. A task `t` is defined by a `t.source` file containing a git remote, and a `t` executable file that will be run on updates to the corresponding repository.
Simply running `forgebuild.sh` will update task repositories, and run tasks which received updates. When positional arguments are passed to forgebuild, only the corresponding tasks are triggered. For example, `forgebuild foo bar` will only check updates for tasks `foo` and `bar`, and run them if updates were found.
Additionally, forgebuild.sh can take a `-f` or `--force` flag which triggers task runs even when no updates were found. This flag is useful when you want to trigger a task which failed because of side-effects outside of the reach of forgebuild, such as a missing package on the system. Similarly to without the `-f` flag, you can give forgebuild a specific list of tasks to trigger.
**Note**: Please remember to make your task scripts executable! `chmod +x` is your friend.
## Logging
Task output is stored in `t.log` for STDOUT, and `t.err` for STDERR. These files are removed on a task run, so that they always contain information about the last build.
If your task respects STDOUT/STDERR convension, you can simply check the size of `t.err` to figure out whether a task failed. If some people would want that, we could further [track task progress/errors](https://tildegit.org/southerntofu/forgebuild.sh/issues/10) and/or introduce [configurable loglevels](https://tildegit.org/forge/build.sh/issues/9).
Some tasks may need additional settings in order to run. A website building task may wish to know about a base URL and a destination folder, for instance. Such information may be placed in the `~/.forgebuild/config/` folder.
Any task receives the `$GITBUILDCONF` environment variable pointing to this repository, unless specific host configuration is found, as will be explained in the next section.
The distinctive feature of `forgebuild.sh` is the host-based configuration system. If a folder matching `$HOSTNAME` is found in your `~/.forgebuild/`, this folder will be passed to the task as `$GITBUILDCONF`, instead of the default configuration folder. If no host-specific configuration is found, the default configuration is used as explained previously.
Additionally, tasks can be configured to always/never run on a specific host. To run a task `t` on a defined list of hosts, place a `t.hosts` file containing a hostname per line in `~/.forgebuild/`. To ignore a task on a specific host, place an empty `t.ignore` file in `~/.forgebuild/$HOSTNAME/`.
To build your own task, you simply need an executable program. If your task executable is a script, don't forget to add the [shebang](https://en.wikipedia.org/wiki/Shebang_(Unix)) (eg `#! /bin/bash`) at the top of your script or it will fail. Please ensure your task is executable (`chmod +x t`) or it will fail.
A task can be any program in any language, that takes exactly one positional argument containing the task name, and the following environment variables:
**Note**: The task name is passed to the task because the task may be a symlink to a program located somewhere else on the system. This is further described in the [Shared build scripts](#shared-build-scripts) section.
This is possible because the task receives the current task name as first (and only) positional argument (`$1`). In the above example, the following commands are run when running `forgebuild.sh`:
This allows for instance to build different websites to different folders, from the same task script. A complex example for that is available in the [zola script](https://tildegit.org/southerntofu/my-forgebuild/src/branch/master/zola) in my `~/.forgebuild`.
`forgebuild.sh` supports naive ordering of tasks because it uses a [glob pattern](https://en.wikipedia.org/wiki/Glob_%28programming%29) (`~/.forgebuild/*.source`) to iterate over files with alphanumeric ordering. This means task `abcd` runs before `dcba`, but `10-dcba` runs before `20-abcd`.
However, tasks can take some time and are therefore run in the background (in parallel). So if you need to run a task precisely after another one, the first task should create a [lockfile](https://en.wikipedia.org/wiki/Glob_%28programming%29), which it removes once done. Then, the second task waits for the first to finish its job.
Of course, you can version your `~/.forgebuild/` in git. This allows you to easily share the same folder across serves and keep them in sync. You can use the following task script to auto-update your folder:
**Note:** You should probably not do something so simple, as other tasks may be running which would make the pull fail, as those files are busy and git cannot write to them. In the future, a more integrated approach to this problem may be taken.
Auto-triggering updates/builds is beyond the scope of this project! You should consider using standard [cronjobs](https://en.wikipedia.org/wiki/Cron) for that.
I'm also interested in running this script through a webhook endpoint for Github/Gitlab/Gitea webhooks, in order to build a simple and reliable CI/CD system. This is not implemented yet and will not be part of this repository, but i will update this README when a such solution is available. If you want to contribute this feature in the meantime, you are more than welcome!
Yes, you read that correctly! The `.forgebuild/forgebuild{,.source}` task provided in this repository is a proof-of-concept autoupdater that will download and install forgebuild updates on every run.
It's a terrible idea for security to autoupdate executables in your $PATH and you probably do not want to do that. But i thought it was a nice demo and it can be useful for people new to the command-line, although this project should not receive too many updates in the future as it is already doing what it is supposed to.
Right now the state of this project is "works for me". It could be useful for other people which is why i just spent a full hour writing this README. However, there could be ways in which `forgebuild.sh` fails you!
If a feature is missing for you, or you encounter a bug, please report it on [tildegit](https://tildegit.org/forge/build.sh/issues) (requires an account on a [tildeverse](https://tildeverse.org) server) or send a mail to southerntofu (@) thunix.net. If you can contribute the feature or fix the bug yourself, your patches are welcome!