utils repository rules

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",
)

download_remote_files

load("@bazel//tools/build_defs/repo:utils.bzl", "download_remote_files")

download_remote_files(ctx, auth)

Utility function for downloading remote files.

This rule is intended to be used in the implementation function of a repository rule. It assumes the parameters remote_file_urls and remote_file_integrity to be present in ctx.attr.

Parameters

`ctx`	required. The repository context of the repository rule calling this utility function.
`auth`	optional. default is `None` An optional dict specifying authentication information for some of the URLs.

get_auth

load("@bazel//tools/build_defs/repo:utils.bzl", "get_auth")

get_auth(ctx, urls)

Utility function to obtain the correct auth dict for a list of urls from .netrc file.

Support optional netrc and auth_patterns attributes if available.

Parameters

`ctx`	required. The repository context of the repository rule calling this utility function.
`urls`	required. the list of urls to read

Returns

the auth dict which can be passed to repository_ctx.download

maybe

load("@bazel//tools/build_defs/repo:utils.bzl", "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

load("@bazel//tools/build_defs/repo:utils.bzl", "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

load("@bazel//tools/build_defs/repo:utils.bzl", "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

load("@bazel//tools/build_defs/repo:utils.bzl", "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

load("@bazel//tools/build_defs/repo:utils.bzl", "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

load("@bazel//tools/build_defs/repo:utils.bzl", "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

load("@bazel//tools/build_defs/repo:utils.bzl", "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

load("@bazel//tools/build_defs/repo:utils.bzl", "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.