v0.4.0
k6x v0.4.0
is here 🎉!
Main new features:
- Builder Service #17
- Filter Extension Registry #20
- Build Cache Location Override #18
- Module replacement #19
Builder Service
The k6x builder service is an HTTP service that generates a k6 binary with the extensions specified in the request. The service is included in the k6x binary, so it can be started using the k6x service
command.
The k6x builder service can be used independently, from the command line (e.g. using curl
or wget
commands), from a web browser
, or from different subcommands of the k6x launcher as a builder called service
.
Usage from the command line
The k6 binary can be easily built using wget , curl or other command-line http client by retrieving the appropriate builder service URL:
using wget
wget --content-disposition https://example.com/linux/amd64/k6@v0.46.0,dashboard@v0.6.0,k6/x/faker@v0.2.2,top@v0.1.1
using curl
curl -OJ https://example.com/linux/amd64/k6@v0.46.0,dashboard@v0.6.0,k6/x/faker@v0.2.2,top@v0.1.1
Usage from k6x
The builder service can be used from k6x using the --builder service
flag:
k6x run --builder service script.js
k6x expects the address of the builder service in the environment variable called K6X_BUILDER_SERVICE
. There is currently no default, it must be specified.
Simplified command line usage
In order to simplify use from the command line, the service also accepts version dependencies in any order. In this case, after unlocking the latest versions and sorting, the response will be an HTTP redirect.
using wget
wget --content-disposition https://example.com/linux/amd64/top,k6/x/faker,dashboard
using curl
curl -OJL https://example.com/linux/amd64/top,k6/x/faker,dashboard
How It Works
The service serves HTTP GET
requests, with a well-defined path structure:
htps://example.com/goos/goarch/dependency-list
Where goos
is the usual operating system name in the go language (e.g. linux
, windows
, darwin
), goarch
is the usual processor architecture in the go language (e.g. amd64
, arm64
). The dependency-list
is a comma-separated list of dependencies, in the following form:
name@version
Where name
is the name of the dependency and version
is the version number according to semver (with an optional leading v
character). The first item in the list is always the dependency named k6
, and the other items are sorted alphabetically by name. For example:
https://example.com/linux/amd64/k6@v0.46.0,dashboard@v0.6.0,k6/x/faker@v0.2.2,top@v0.1.1
Based on the platform parameters (goos
, goarch
) and dependencies, the service prepares the k6 binary.
Since the response (the k6 binary) depends only on the request path, it can be easily cached. The service therefore sets a sufficiently long caching period (at least one year) in the response, as well as the usual cache headers (e.g. ETag
). By placing a caching proxy in front of the service, it can be ensured that the actual k6 binary build takes place only once for each parameter combination.
The advantage of the solution is that the k6 binary is created on the fly, only for the parameter combinations that are actually used. Since the service preserves the go cache between builds, a specific build happens quickly enough.
Filter Extension Registry
In certain runtime environments, the use of arbitrary extensions is not allowed. There is a need to limit the extensions that can be used.
This use case can be solved most flexibly by narrowing down the extension registry. The content of the extension registry can be narrowed using a jmespath syntax filter expression. Extensions can be filtered based on any property.
allow only officially supported extensions
k6x --filter "[?contains(tiers,'Official')]" run script.js
allow only cloud enabled extensions
k6x --filter "[?cloudEnabled == true]" run script.js
Build Cache Location Override
Reusable artifacts (k6 binary, HTTP responses) are stored in the subdirectory k6x
under the directory defined by the XDG_CACHE_HOME
environment variable. The default of XDG_CACHE_HOME
depends on the operating system (Windows: %LOCALAPPDATA%\cache
, Linux: ~/.cache
, macOS: ~/Library/Caches
). The default cache directory now can be changed using the K6X_CACHE_DIR
environment variable or the --cache-dir
flag.
Module Replacement
In some cases, it can be useful to use another path instead of the module path registered in the extension registry. For example, using a forked repository, or using a local file-system path in the case of a native builder. These use cases can be solved by the module replacement feature.
Usage:
--replace name=path
replaces the module path, where name
is the dependency/module name and path
is a remote module path (version should be appended with @
) or an absolute local file-system path (a path starting with .
can also be used, which will be resolved to an absolute path). It implies the use of the native
builder (--builder native
) and clean flag (--clean
)
with local file-system path
k6x --replace k6/x/faker=../xk6-faker run script.js
with remote path
k6x --replace k6/x/faker=github.com/my-user/xk6-faker@latest run script.js