1. Your first project
To get a feel for the basics, we’ll start with the most basic BuildStream project we could think of.
Note
This example is distributed with BuildStream in the doc/examples/first-project subdirectory.
1.1. Creating the project
First, lets create the project itself using the convenience bst init command to create a little project structure:
user@host:~/first-project$ bst init --project-name first-project
Created project.conf at: /home/user/buildstream/doc/examples/first-project/project.conf
This will give you a project.conf which will look like this:
1.1.1. project.conf
# Unique project name
name: first-project
# Required BuildStream format version
format-version: 18
# Subdirectory where elements are stored
element-path: elements
The project.conf is a central point of configuration for your BuildStream project.
1.2. Add some content
BuildStream processes directory trees as input and output,
so let’s just create a hello.world file for the project
to have.
user@host:~/first-project$ touch hello.world
1.3. Declare the element
Here we’re going to declare a simple import element
which will import the hello.world file we’ve created in the previous step.
Create elements/hello.bst with the following content:
1.3.1. elements/hello.bst
kind: import
# Use a local source to stage our file
sources:
- kind: local
path: hello.world
# Configure the import element
config:
# Place the content staged by sources at the
# root of the output artifact
target: /
1.3.2. The source
The local source used by the hello.bst element,
can be used to access files or directories which are stored in the same repository
as your BuildStream project. The hello.bst element uses the local
source to stage our local hello.world file.
1.3.3. The element
The import element can be used to simply add content
directly to the output artifacts. In this case, it simply takes the hello.world file
provided by it’s source and stages it directly to the artifact output root.
Tip
In this example so far we’ve used two plugins, the local
source and the import element.
You can always browse the documentation for all plugins in the plugins section of the manual.
1.4. Build the element
In order to carry out the activities of the import element
we’ve declared, we’re going to have to ask BuildStream to build.
This process will collect all of the sources required for the specified hello.bst
and get the backing import element to generate an artifact
for us.
user@host:~/first-project$ bst build hello.bst
[--:--:--][][] STATUS Cache usage recomputed: 12K / infinity (0%)
[--:--:--][][] START Build
[--:--:--][][] START Loading elements
[00:00:00][][] SUCCESS Loading elements
[--:--:--][][] START Resolving elements
[00:00:00][][] SUCCESS Resolving elements
[--:--:--][][] START Resolving cached state
[00:00:00][][] SUCCESS Resolving cached state
[--:--:--][][] START Checking sources
[00:00:00][][] SUCCESS Checking sources
BuildStream Version 1.6.9+0.g4abd1f3e1.dirty
Session Start: Tuesday, 21-02-2023 at 14:38:23
Project: first-project (/home/user/buildstream/doc/examples/first-project)
Targets: hello.bst
Cache Usage: 12K / infinity (0%)
User Configuration
Configuration File: /home/user/buildstream/doc/run-bst-gw3b05t2/buildstream.conf
Log Files: /home/user/buildstream/doc/run-bst-gw3b05t2/logs
Source Mirrors: /home/user/buildstream/doc/run-bst-gw3b05t2/sources
Build Area: /home/user/buildstream/doc/run-bst-gw3b05t2/build
Artifact Cache: /home/user/buildstream/doc/run-bst-gw3b05t2/artifacts
Strict Build Plan: Yes
Maximum Fetch Tasks: 10
Maximum Build Tasks: 4
Maximum Push Tasks: 4
Maximum Network Retries: 2
Pipeline
buildable 7c73774896fecfd2be0710a3c9dbcdf5fb79f892091d951ef00f09e95f2988c2 hello.bst
===============================================================================
[--:--:--][7c737748][build:hello.bst ] START first-project/hello/7c737748-build.1351.log
[--:--:--][7c737748][build:hello.bst ] START Staging sources
[00:00:00][7c737748][build:hello.bst ] SUCCESS Staging sources
[--:--:--][7c737748][build:hello.bst ] START Caching artifact
[00:00:00][7c737748][build:hello.bst ] SUCCESS Caching artifact
[00:00:00][7c737748][build:hello.bst ] SUCCESS first-project/hello/7c737748-build.1351.log
[00:00:00][][] SUCCESS Build
Pipeline Summary
Total: 1
Session: 1
Fetch Queue: processed 0, skipped 1, failed 0
Build Queue: processed 1, skipped 0, failed 0
Now the artifact is ready.
Using bst show, we can observe that the artifact’s state, which was reported
as buildable in the bst build command above, has now changed to cached:
user@host:~/first-project$ bst show hello.bst
[--:--:--][][] START Loading elements
[00:00:00][][] SUCCESS Loading elements
[--:--:--][][] START Resolving elements
[00:00:00][][] SUCCESS Resolving elements
[--:--:--][][] START Resolving cached state
[00:00:00][][] SUCCESS Resolving cached state
cached 7c73774896fecfd2be0710a3c9dbcdf5fb79f892091d951ef00f09e95f2988c2 hello.bst
1.5. Observe the output
Now that we’ve finished building, we can checkout the output of the artifact we’ve created using bst checkout
user@host:~/first-project$ bst checkout hello.bst here
[--:--:--][][] START Loading elements
[00:00:00][][] SUCCESS Loading elements
[--:--:--][][] START Resolving elements
[00:00:00][][] SUCCESS Resolving elements
[--:--:--][][] START Resolving cached state
[00:00:00][][] SUCCESS Resolving cached state
[--:--:--][7c737748][ main:hello.bst ] START Staging dependencies
[00:00:00][7c737748][ main:hello.bst ] SUCCESS Staging dependencies
[--:--:--][7c737748][ main:hello.bst ] START Integrating sandbox
[00:00:00][7c737748][ main:hello.bst ] SUCCESS Integrating sandbox
[--:--:--][7c737748][ main:hello.bst ] START Checking out files in 'here'
[00:00:00][7c737748][ main:hello.bst ] SUCCESS Checking out files in 'here'
And observe that the file we expect is there:
user@host:~/first-project$ ls ./here
hello.world
1.6. Summary
In this section we’ve created our first BuildStream project from scratch, but it doesnt do much.
We’ve observed the general structure of a BuildStream project, and we’ve run our first build.