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 version
min-version: 2.3
# 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 its 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
[--:--:--][ ][ main:core activity ] START Build
[--:--:--][ ][ main:core activity ] START Loading elements
[00:00:00][ ][ main:core activity ] SUCCESS Loading elements
[--:--:--][ ][ main:core activity ] START Resolving elements
WARNING: All log messages before absl::InitializeLog() is called are written to STDERR
I0000 00:00:1730888203.763861 2831 config.cc:230] gRPC experiments enabled: call_status_override_on_cancellation, event_engine_dns, event_engine_listener, http2_stats_fix, monitoring_experiment, pick_first_new, trace_record_callops, work_serializer_clears_time_cache
[00:00:00][ ][ main:core activity ] SUCCESS Resolving elements
[--:--:--][ ][ main:core activity ] START Initializing remote caches
[00:00:00][ ][ main:core activity ] SUCCESS Initializing remote caches
[--:--:--][ ][ main:core activity ] START Query cache
[00:00:00][ ][ main:core activity ] SUCCESS Query cache
BuildStream Version 2.3.0+26.g65e2074ad
Session Start: Wednesday, 06-11-2024 at 10:16:43
Project: first-project (/home/user/buildstream/doc/examples/first-project)
Targets: hello.bst
User Configuration
Configuration File: /home/user/buildstream/doc/run-bst-hxcfj_9g/buildstream.conf
Cache Directory: /home/user/buildstream/doc/run-bst-hxcfj_9g
Log Files: /home/user/buildstream/doc/run-bst-hxcfj_9g/logs
Source Mirrors: /home/user/buildstream/doc/run-bst-hxcfj_9g/sources
Build Area: /home/user/buildstream/doc/run-bst-hxcfj_9g/build
Strict Build Plan: Yes
Maximum Fetch Tasks: 10
Maximum Build Tasks: 4
Maximum Push Tasks: 4
Maximum Network Retries: 2
Project: first-project
Element Plugins
import: core plugin
Source Plugins
local: core plugin
Pipeline
buildable 8b3d535225335b4842b5d6b98ee6fdffc7340e190f33b79a2043f5c31e43fbde hello.bst
===============================================================================
[--:--:--][8b3d5352][ fetch:hello.bst ] START first-project/hello/8b3d5352-fetch.20241106-101643.log
[00:00:00][8b3d5352][ fetch:hello.bst ] SUCCESS first-project/hello/8b3d5352-fetch.20241106-101643.log
[--:--:--][8b3d5352][ build:hello.bst ] START first-project/hello/8b3d5352-build.20241106-101643.log
[--:--:--][8b3d5352][ build:hello.bst ] START Staging sources
[00:00:00][8b3d5352][ build:hello.bst ] SUCCESS Staging sources
[--:--:--][8b3d5352][ build:hello.bst ] START Caching artifact
[00:00:00][8b3d5352][ build:hello.bst ] SUCCESS Caching artifact
[00:00:00][8b3d5352][ build:hello.bst ] SUCCESS first-project/hello/8b3d5352-build.20241106-101643.log
[00:00:00][ ][ main:core activity ] SUCCESS Build
Pipeline Summary
Total: 1
Session: 1
Fetch Queue: processed 1, skipped 0, 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
[--:--:--][ ][ main:core activity ] START Loading elements
[00:00:00][ ][ main:core activity ] SUCCESS Loading elements
[--:--:--][ ][ main:core activity ] START Resolving elements
WARNING: All log messages before absl::InitializeLog() is called are written to STDERR
I0000 00:00:1730888204.179921 2861 config.cc:230] gRPC experiments enabled: call_status_override_on_cancellation, event_engine_dns, event_engine_listener, http2_stats_fix, monitoring_experiment, pick_first_new, trace_record_callops, work_serializer_clears_time_cache
[00:00:00][ ][ main:core activity ] SUCCESS Resolving elements
[--:--:--][ ][ main:core activity ] START Initializing remote caches
[00:00:00][ ][ main:core activity ] SUCCESS Initializing remote caches
[--:--:--][ ][ main:core activity ] START Query cache
[00:00:00][ ][ main:core activity ] SUCCESS Query cache
cached 8b3d535225335b4842b5d6b98ee6fdffc7340e190f33b79a2043f5c31e43fbde 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 artifact checkout
user@host:~/first-project$ bst artifact checkout --directory here hello.bst
[--:--:--][ ][ main:core activity ] START Loading elements
[00:00:00][ ][ main:core activity ] SUCCESS Loading elements
[--:--:--][ ][ main:core activity ] START Resolving elements
WARNING: All log messages before absl::InitializeLog() is called are written to STDERR
I0000 00:00:1730888204.601576 2890 config.cc:230] gRPC experiments enabled: call_status_override_on_cancellation, event_engine_dns, event_engine_listener, http2_stats_fix, monitoring_experiment, pick_first_new, trace_record_callops, work_serializer_clears_time_cache
[00:00:00][ ][ main:core activity ] SUCCESS Resolving elements
[--:--:--][ ][ main:core activity ] START Initializing remote caches
[00:00:00][ ][ main:core activity ] SUCCESS Initializing remote caches
[--:--:--][ ][ main:core activity ] START Query cache
[00:00:00][ ][ main:core activity ] SUCCESS Query cache
[--:--:--][8b3d5352][ main:hello.bst ] START Staging dependencies
[00:00:00][8b3d5352][ main:hello.bst ] SUCCESS Staging dependencies
[--:--:--][8b3d5352][ main:hello.bst ] START Integrating sandbox
[00:00:00][8b3d5352][ main:hello.bst ] SUCCESS Integrating sandbox
[--:--:--][8b3d5352][ main:hello.bst ] START Checking out files in 'here'
[00:00:00][8b3d5352][ 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.