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 NoneAn optional dict specifying authentication information for some of the URLs. | 
Returns
dict mapping file paths to a download info.
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 "a .netrc file"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 NoneThe patch files to apply. List of strings, Labels, or paths. | 
| patch_cmds | optional.
default is NoneBash commands to run for patching, passed one at a time to bash -c. List of strings | 
| patch_cmds_win | optional.
default is NonePowershell 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 NonePath of the patch tool to execute for applying patches. String. | 
| patch_args | optional.
default is NoneArguments to pass to the patch tool. List of strings. | 
| auth | optional.
default is NoneAn optional dict specifying authentication information for some of the URLs. | 
Returns
dict mapping remote patch URLs to a download info.
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 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, and build_file_content to
be present in ctx.attr; the latter two possibly with value None.
Parameters
| ctx | required. The repository context of the repository rule calling this utility function. |