4. Integration commands
Sometimes a software requires more configuration or processing than what is performed at installation time, otherwise it will not run properly.
This is especially true in cases where a daemon or library interoperates with third party extensions and needs to maintain a system wide cache whenever its extensions are installed or removed; system wide font caches are an example of this.
In these cases we use integration commands to ensure that a runtime is ready to run after all of its components have been staged.
Note
This example is distributed with BuildStream in the doc/examples/integration-commands subdirectory.
4.1. Overview
In this chapter, we’ll be exploring integration commands, which will be our first look at public data.
4.2. Project structure
4.2.1. project.conf and elements/base.bst
The project.conf and base stack stack element are configured in the
same way as in the previous chapter: Running commands.
4.2.2. elements/base/alpine.bst
kind: import
description: |
Alpine Linux base runtime
sources:
- kind: tar
url: alpine:integration-tests-base.v1.x86_64.tar.xz
ref: 3eb559250ba82b64a68d86d0636a6b127aa5f6d25d3601a79f79214dc9703639
#
# Run ldconfig in the libdir before running anything
#
public:
bst:
integration-commands:
- ldconfig "%{libdir}"
This is the same base/alpine.bst we’ve seen in previous chapters,
except that we’ve added an integration command.
This informs BuildStream that whenever the output of this element is
expected to run, this command should be run first. In this case we
are simply running ldconfig as a precautionary measure, to ensure
that the runtime linker is ready to find any shared libraries we may
have added to %{libdir}.
4.2.2.1. Looking at public data
The integration commands used here is the first time we’ve used any builtin public data.
Public data is a free form portion of an element’s configuration and is not necessarily understood by the element on which it is declared, public data is intended to be read by its reverse dependency elements.
This allows annotations on some elements to inform elements later in the dependency chain about details of its artifact, or to suggest how it should be processed.
4.2.3. elements/libhello.bst and elements/hello.bst
These are basically manual elements very similar to the ones we’ve seen in the previous chapter: Running commands.
These produce a library and a hello program which uses the library, we will consider these irrelevant to the topic and leave examination of their sources as an exercise for the reader.
4.3. Using the project
4.3.1. Build the hello.bst element
To build the project, run bst build in the following way:
user@host:~/integration-commands$ 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
[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+44.g11760f95e
Session Start: Wednesday, 27-11-2024 at 11:03:58
Project: integration-commands (/home/user/buildstream/doc/examples/integration-commands)
Targets: hello.bst
User Configuration
Configuration File: /home/user/buildstream/doc/run-bst-ttu_4jhm/buildstream.conf
Cache Directory: /home/user/buildstream/doc/run-bst-ttu_4jhm
Log Files: /home/user/buildstream/doc/run-bst-ttu_4jhm/logs
Source Mirrors: /home/user/buildstream/doc/run-bst-ttu_4jhm/sources
Build Area: /home/user/buildstream/doc/run-bst-ttu_4jhm/build
Strict Build Plan: Yes
Maximum Fetch Tasks: 10
Maximum Build Tasks: 4
Maximum Push Tasks: 4
Maximum Network Retries: 2
Project: integration-commands
Element Plugins
manual: core plugin
stack: core plugin
import: core plugin
Source Plugins
local: core plugin
tar: core plugin
Pipeline
fetch needed 5ff937aaa74f04d961f639c06d636e4a93abbc3a8d289a10ae8084f1d800a2de base/alpine.bst
waiting 0848bf1769eb7f774cfe146212b0cfe56f9d7b7320832c93a7823e50ab993138 base.bst
waiting 3cf9edd00c109f063e4a0c30d826420e6d240e59ee10241d59b22a7883ecef4f libhello.bst
waiting 76f82637c19f9595a18d2e480da027552cb53811e39b7481b2feb767f0d2311d hello.bst
===============================================================================
[--:--:--][5ff937aa][ fetch:base/alpine.bst ] START integration-commands/base-alpine/5ff937aa-fetch.20241127-110358.log
[--:--:--][5ff937aa][ fetch:base/alpine.bst ] START Fetching https://bst-integration-test-images.ams3.cdn.digitaloceanspaces.com/integration-tests-base.v1.x86_64.tar.xz
[--:--:--][0848bf17][ fetch:base.bst ] START integration-commands/base/0848bf17-fetch.20241127-110358.log
[--:--:--][3cf9edd0][ fetch:libhello.bst ] START integration-commands/libhello/3cf9edd0-fetch.20241127-110358.log
[00:00:00][0848bf17][ fetch:base.bst ] SUCCESS integration-commands/base/0848bf17-fetch.20241127-110358.log
[00:00:00][3cf9edd0][ fetch:libhello.bst ] SUCCESS integration-commands/libhello/3cf9edd0-fetch.20241127-110358.log
[00:00:00][5ff937aa][ fetch:base/alpine.bst ] SUCCESS Fetching https://bst-integration-test-images.ams3.cdn.digitaloceanspaces.com/integration-tests-base.v1.x86_64.tar.xz
[00:00:06][5ff937aa][ fetch:base/alpine.bst ] SUCCESS integration-commands/base-alpine/5ff937aa-fetch.20241127-110358.log
[--:--:--][5ff937aa][ build:base/alpine.bst ] START integration-commands/base-alpine/5ff937aa-build.20241127-110405.log
[--:--:--][5ff937aa][ build:base/alpine.bst ] START Staging sources
[00:00:00][5ff937aa][ build:base/alpine.bst ] SUCCESS Staging sources
[--:--:--][5ff937aa][ build:base/alpine.bst ] START Caching artifact
[00:00:00][5ff937aa][ build:base/alpine.bst ] SUCCESS Caching artifact
[00:00:00][5ff937aa][ build:base/alpine.bst ] SUCCESS integration-commands/base-alpine/5ff937aa-build.20241127-110405.log
[--:--:--][0848bf17][ build:base.bst ] START integration-commands/base/0848bf17-build.20241127-110405.log
[--:--:--][0848bf17][ build:base.bst ] START Caching artifact
[00:00:00][0848bf17][ build:base.bst ] SUCCESS Caching artifact
[00:00:00][0848bf17][ build:base.bst ] SUCCESS integration-commands/base/0848bf17-build.20241127-110405.log
[--:--:--][3cf9edd0][ build:libhello.bst ] START integration-commands/libhello/3cf9edd0-build.20241127-110405.log
[--:--:--][3cf9edd0][ build:libhello.bst ] START Staging dependencies at: /
[00:00:00][3cf9edd0][ build:libhello.bst ] SUCCESS Staging dependencies at: /
[--:--:--][3cf9edd0][ build:libhello.bst ] START Integrating sandbox
[00:00:00][3cf9edd0][ build:libhello.bst ] SUCCESS Integrating sandbox
[--:--:--][3cf9edd0][ build:libhello.bst ] START Staging sources
[00:00:00][3cf9edd0][ build:libhello.bst ] SUCCESS Staging sources
[--:--:--][3cf9edd0][ build:libhello.bst ] START Running commands
make PREFIX="/usr"
make -j1 PREFIX="/usr" DESTDIR="/buildstream-install" install
[00:00:00][3cf9edd0][ build:libhello.bst ] SUCCESS Running commands
[--:--:--][3cf9edd0][ build:libhello.bst ] START Caching artifact
[00:00:00][3cf9edd0][ build:libhello.bst ] SUCCESS Caching artifact
[00:00:01][3cf9edd0][ build:libhello.bst ] SUCCESS integration-commands/libhello/3cf9edd0-build.20241127-110405.log
[--:--:--][76f82637][ build:hello.bst ] START integration-commands/hello/76f82637-build.20241127-110406.log
[--:--:--][76f82637][ build:hello.bst ] START Staging dependencies at: /
[00:00:00][76f82637][ build:hello.bst ] SUCCESS Staging dependencies at: /
[--:--:--][76f82637][ build:hello.bst ] START Integrating sandbox
[00:00:00][76f82637][ build:hello.bst ] SUCCESS Integrating sandbox
[--:--:--][76f82637][ build:hello.bst ] START Staging sources
[00:00:00][76f82637][ build:hello.bst ] SUCCESS Staging sources
[--:--:--][76f82637][ build:hello.bst ] START Running commands
make PREFIX="/usr"
make -j1 PREFIX="/usr" DESTDIR="/buildstream-install" install
[00:00:00][76f82637][ build:hello.bst ] SUCCESS Running commands
[--:--:--][76f82637][ build:hello.bst ] START Caching artifact
[00:00:00][76f82637][ build:hello.bst ] SUCCESS Caching artifact
[00:00:01][76f82637][ build:hello.bst ] SUCCESS integration-commands/hello/76f82637-build.20241127-110406.log
[00:00:09][ ][ main:core activity ] SUCCESS Build
Pipeline Summary
Total: 4
Session: 4
Fetch Queue: processed 3, skipped 1, failed 0
Build Queue: processed 4, skipped 0, failed 0
Observe in the build process above, the integration command declared on the
base/alpine.bst element is run after staging the dependency artifacts
into the build sandbox and before running any of the build commands, for
both of the libhello.bst and hello.bst elements.
BuildStream assumes that commands which are to be run in the build sandbox need to be run in an integrated sandbox.
Tip
Integration commands can be taxing on your overall build process, because they need to run at the beginning of every build which runtime depends on the element declaring them.
For this reason, it is better to leave out more onerous tasks if they are not needed at software build time, and handle those specific tasks differently later in the pipeline, before deployment.
4.3.2. Run the hello world program
Unlike the previous chapters, this hello world program takes an argument, we can invoke the program using bst shell:
user@host:~/integration-commands$ bst shell hello.bst -- hello pony
[--:--:--][ ][ main:core activity ] START Loading elements
[00:00:00][ ][ main:core activity ] SUCCESS Loading elements
[--:--:--][ ][ main:core activity ] START Resolving elements
[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
[--:--:--][76f82637][ main:hello.bst ] START Staging dependencies
[00:00:00][76f82637][ main:hello.bst ] SUCCESS Staging dependencies
[--:--:--][76f82637][ main:hello.bst ] START Integrating sandbox
[--:--:--][ ][ main:hello.bst ] START Running commands
ldconfig "/usr/lib"
+ sh -e -c ldconfig "/usr/lib"
[00:00:00][ ][ main:hello.bst ] SUCCESS Running commands
[00:00:00][76f82637][ main:hello.bst ] SUCCESS Integrating sandbox
[--:--:--][76f82637][ main:hello.bst ] STATUS Running command
hello pony
Hello pony
Here we see again, the integration commands are also used when preparing the shell to launch a command.
4.4. Summary
In this chapter we’ve observed how integration commands work, and we now know about public data, which plugins can read from their dependencies in order to influence their build process.