The following functions can be loaded from
@bazel_tools//tools/build_defs/repo:utils.bzl.
Utils for manipulating external repositories, once fetched.
Setup
These utilities are intended to be used by other repository rules. They can be loaded as follows.
load(
"@bazel_tools//tools/build_defs/repo:utils.bzl",
"workspace_and_buildfile",
"patch",
"update_attrs",
)
maybe
maybe(repo_rule, name, kwargs)
Utility function for only adding a repository if it's not already present.
This is to implement safe repositories.bzl macro documented in https://bazel.build/rules/deploying#dependencies.
Parameters
repo_rule |
required.
repository rule function. |
name |
required.
name of the repository to create. |
kwargs |
optional.
remaining arguments that are passed to the repo_rule function. |
Returns
Nothing, defines the repository when needed as a side-effect.
parse_netrc
parse_netrc(contents, filename)
Utility function to parse at least a basic .netrc file.
Parameters
contents |
required.
input for the parser. |
filename |
optional.
default is None
filename to use in error messages, if any. |
Returns
dict mapping a machine names to a dict with the information provided about them
patch
patch(ctx, patches, patch_cmds, patch_cmds_win, patch_tool, patch_args, auth)
Implementation of patching an already extracted repository.
This rule is intended to be used in the implementation function of
a repository rule. If the parameters patches, patch_tool,
patch_args, patch_cmds and patch_cmds_win are not specified
then they are taken from ctx.attr.
Parameters
ctx |
required.
The repository context of the repository rule calling this utility function. |
patches |
optional.
default is None
The patch files to apply. List of strings, Labels, or paths. |
patch_cmds |
optional.
default is None
Bash commands to run for patching, passed one at a time to bash -c. List of strings |
patch_cmds_win |
optional.
default is None
Powershell commands to run for patching, passed one at a time to powershell /c. List of strings. If the boolean value of this parameter is false, patch_cmds will be used and this parameter will be ignored. |
patch_tool |
optional.
default is None
Path of the patch tool to execute for applying patches. String. |
patch_args |
optional.
default is None
Arguments to pass to the patch tool. List of strings. |
auth |
optional.
default is None
An optional dict specifying authentication information for some of the URLs. |
read_netrc
read_netrc(ctx, filename)
Utility function to parse at least a basic .netrc file.
Parameters
ctx |
required.
The repository context of the repository rule calling this utility function. |
filename |
required.
the name of the .netrc file to read |
Returns
dict mapping a machine names to a dict with the information provided about them
read_user_netrc
read_user_netrc(ctx)
Read user's default netrc file.
Parameters
ctx |
required.
The repository context of the repository rule calling this utility function. |
Returns
dict mapping a machine names to a dict with the information provided about them.
update_attrs
update_attrs(orig, keys, override)
Utility function for altering and adding the specified attributes to a particular repository rule invocation.
This is used to make a rule reproducible.
Parameters
orig |
required.
dict of actually set attributes (either explicitly or implicitly) by a particular rule invocation |
keys |
required.
complete set of attributes defined on this rule |
override |
required.
dict of attributes to override or add to orig |
Returns
dict of attributes with the keys from override inserted/updated
use_netrc
use_netrc(netrc, urls, patterns)
Compute an auth dict from a parsed netrc file and a list of URLs.
Parameters
netrc |
required.
a netrc file already parsed to a dict, e.g., as obtained from read_netrc |
urls |
required.
a list of URLs. |
patterns |
required.
optional dict of url to authorization patterns |
Returns
dict suitable as auth argument for ctx.download; more precisely, the dict will map all URLs where the netrc file provides login and password to a dict containing the corresponding login, password and optional authorization pattern, as well as the mapping of "type" to "basic" or "pattern".
workspace_and_buildfile
workspace_and_buildfile(ctx)
Utility function for writing WORKSPACE and, if requested, a BUILD file.
This rule is intended to be used in the implementation function of a
repository rule.
It assumes the parameters name, build_file, build_file_content,
workspace_file, and workspace_file_content to be
present in ctx.attr; the latter four possibly with value None.
Parameters
ctx |
required.
The repository context of the repository rule calling this utility function. |