The following functions can be loaded from @bazel_tools//tools/build_defs/repo:http.bzl.

http_archive

http_archive(name, auth_patterns, build_file, build_file_content, canonical_id, netrc, patch_args, patch_cmds, patch_cmds_win, patch_tool, patches, sha256, strip_prefix, type, url, urls, workspace_file, workspace_file_content)

Downloads a Bazel repository as a compressed archive file, decompresses it, and makes its targets available for binding.

It supports the following file extensions: "zip", "jar", "war", "tar", "tar.gz", "tgz", "tar.xz", and tar.bz2.

Examples: Suppose the current repository contains the source code for a chat program, rooted at the directory ~/chat-app. It needs to depend on an SSL library which is available from http://example.com/openssl.zip. This .zip file contains the following directory structure:

  WORKSPACE
  src/
    openssl.cc
    openssl.h

In the local repository, the user creates a openssl.BUILD file which contains the following target definition:

  cc_library(
      name = "openssl-lib",
      srcs = ["src/openssl.cc"],
      hdrs = ["src/openssl.h"],
  )

Targets in the ~/chat-app repository can depend on this target if the following lines are added to ~/chat-app/WORKSPACE:

  load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_archive")

  http_archive(
      name = "my_ssl",
      urls = ["http://example.com/openssl.zip"],
      sha256 = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
      build_file = "@//:openssl.BUILD",
  )

Then targets would specify @my_ssl//:openssl-lib as a dependency.

Attributes

name Name; required

A unique name for this repository.

auth_patterns Dictionary: String -> String; optional

An optional dict mapping host names to custom authorization patterns. If a URL's host name is present in this dict the value will be used as a pattern when generating the authorization header for the http request. This enables the use of custom authorization schemes used in a lot of common cloud storage providers. The pattern currently supports 2 tokens: <login> and <password>, which are replaced with their equivalent value in the netrc file for the same host name. After formatting, the result is set as the value for the Authorization field of the HTTP request. Example attribute and netrc for a http download to an oauth2 enabled API using a bearer token: 

auth_patterns = {
    "storage.cloudprovider.com": "Bearer <password>"
}
netrc: 
machine storage.cloudprovider.com
        password RANDOM-TOKEN
The final HTTP request would have the following header: 
Authorization: Bearer RANDOM-TOKEN

build_file Label; optional

The file to use as the BUILD file for this repository.This attribute is an absolute label (use '@//' for the main repo). The file does not need to be named BUILD, but can be (something like BUILD.new-repo-name may work well for distinguishing it from the repository's actual BUILD files. Either build_file or build_file_content can be specified, but not both.

build_file_content String; optional

The content for the BUILD file for this repository. Either build_file or build_file_content can be specified, but not both.

canonical_id String; optional

A canonical id of the archive downloaded. If specified and non-empty, bazel will not take the archive from cache, unless it was added to the cache by a request with the same canonical id.

netrc String; optional

Location of the .netrc file to use for authentication

patch_args List of strings; optional

The arguments given to the patch tool. Defaults to -p0, however -p1 will usually be needed for patches generated by git. If multiple -p arguments are specified, the last one will take effect.If arguments other than -p are specified, Bazel will fall back to use patch command line tool instead of the Bazel-native patch implementation. When falling back to patch command line tool and patch_tool attribute is not specified, `patch` will be used.

patch_cmds List of strings; optional

Sequence of Bash commands to be applied on Linux/Macos after patches are applied.

patch_cmds_win List of strings; optional

Sequence of Powershell commands to be applied on Windows after patches are applied. If this attribute is not set, patch_cmds will be executed on Windows, which requires Bash binary to exist.

patch_tool String; optional

The patch(1) utility to use. If this is specified, Bazel will use the specifed patch tool instead of the Bazel-native patch implementation.

patches List of labels; optional

A list of files that are to be applied as patches after extracting the archive. By default, it uses the Bazel-native patch implementation which doesn't support fuzz match and binary patch, but Bazel will fall back to use patch command line tool if `patch_tool` attribute is specified or there are arguments other than `-p` in `patch_args` attribute.

sha256 String; optional

The expected SHA-256 of the file downloaded. This must match the SHA-256 of the file downloaded. _It is a security risk to omit the SHA-256 as remote files can change._ At best omitting this field will make your build non-hermetic. It is optional to make development easier but should be set before shipping.

strip_prefix String; optional

A directory prefix to strip from the extracted files. Many archives contain a top-level directory that contains all of the useful files in archive. Instead of needing to specify this prefix over and over in the `build_file`, this field can be used to strip it from all of the extracted files. For example, suppose you are using `foo-lib-latest.zip`, which contains the directory `foo-lib-1.2.3/` under which there is a `WORKSPACE` file and are `src/`, `lib/`, and `test/` directories that contain the actual code you wish to build. Specify `strip_prefix = "foo-lib-1.2.3"` to use the `foo-lib-1.2.3` directory as your top-level directory. Note that if there are files outside of this directory, they will be discarded and inaccessible (e.g., a top-level license file). This includes files/directories that start with the prefix but are not in the directory (e.g., `foo-lib-1.2.3.release-notes`). If the specified prefix does not match a directory in the archive, Bazel will return an error.

type String; optional

The archive type of the downloaded file. By default, the archive type is determined from the file extension of the URL. If the file has no extension, you can explicitly specify one of the following: `"zip"`, `"jar"`, `"war"`, `"tar"`, `"tar.gz"`, `"tgz"`, `"tar.xz"`, or `tar.bz2`.

url String; optional

A URL to a file that will be made available to Bazel. This must be a file, http or https URL. Redirections are followed. Authentication is not supported. This parameter is to simplify the transition from the native http_archive rule. More flexibility can be achieved by the urls parameter that allows to specify alternative URLs to fetch from.

urls List of strings; optional

A list of URLs to a file that will be made available to Bazel. Each entry must be a file, http or https URL. Redirections are followed. Authentication is not supported.

workspace_file Label; optional

The file to use as the `WORKSPACE` file for this repository. Either `workspace_file` or `workspace_file_content` can be specified, or neither, but not both.

workspace_file_content String; optional

The content for the WORKSPACE file for this repository. Either `workspace_file` or `workspace_file_content` can be specified, or neither, but not both.

http_file

http_file(name, auth_patterns, canonical_id, downloaded_file_path, executable, netrc, sha256, urls)

Downloads a file from a URL and makes it available to be used as a file group.

Examples: Suppose you need to have a debian package for your custom rules. This package is available from http://example.com/package.deb. Then you can add to your WORKSPACE file:

  load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_file")

  http_file(
      name = "my_deb",
      urls = ["http://example.com/package.deb"],
      sha256 = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
  )

Targets would specify @my_deb//file as a dependency to depend on this file.

Attributes

name Name; required

A unique name for this repository.

auth_patterns Dictionary: String -> String; optional

An optional dict mapping host names to custom authorization patterns. If a URL's host name is present in this dict the value will be used as a pattern when generating the authorization header for the http request. This enables the use of custom authorization schemes used in a lot of common cloud storage providers. The pattern currently supports 2 tokens: <login> and <password>, which are replaced with their equivalent value in the netrc file for the same host name. After formatting, the result is set as the value for the Authorization field of the HTTP request. Example attribute and netrc for a http download to an oauth2 enabled API using a bearer token: 

auth_patterns = {
    "storage.cloudprovider.com": "Bearer <password>"
}
netrc: 
machine storage.cloudprovider.com
        password RANDOM-TOKEN
The final HTTP request would have the following header: 
Authorization: Bearer RANDOM-TOKEN

canonical_id String; optional

A canonical id of the archive downloaded. If specified and non-empty, bazel will not take the archive from cache, unless it was added to the cache by a request with the same canonical id.

downloaded_file_path String; optional

Path assigned to the file downloaded

executable Boolean; optional

If the downloaded file should be made executable.

netrc String; optional

Location of the .netrc file to use for authentication

sha256 String; optional

The expected SHA-256 of the file downloaded. This must match the SHA-256 of the file downloaded. _It is a security risk to omit the SHA-256 as remote files can change._ At best omitting this field will make your build non-hermetic. It is optional to make development easier but should be set before shipping.

urls List of strings; required

A list of URLs to a file that will be made available to Bazel. Each entry must be a file, http or https URL. Redirections are followed. Authentication is not supported.

http_jar

http_jar(name, auth_patterns, canonical_id, netrc, sha256, url, urls)

Downloads a jar from a URL and makes it available as java_import

Downloaded files must have a .jar extension.

Examples: Suppose the current repository contains the source code for a chat program, rooted at the directory ~/chat-app. It needs to depend on an SSL library which is available from http://example.com/openssl-0.2.jar.

Targets in the ~/chat-app repository can depend on this target if the following lines are added to ~/chat-app/WORKSPACE:

  load("@bazel_tools//tools/build_defs/repo:http.bzl", "http_jar")

  http_jar(
      name = "my_ssl",
      url = "http://example.com/openssl-0.2.jar",
      sha256 = "e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855",
  )

Targets would specify <code>@my_ssl//jar</code> as a dependency to depend on this jar.

You may also reference files on the current system (localhost) by using “file:///path/to/file” if you are on Unix-based systems. If you’re on Windows, use “file:///c:/path/to/file”. In both examples, note the three slashes (/) – the first two slashes belong to file:// and the third one belongs to the absolute path to the file.

Attributes

name Name; required

A unique name for this repository.

auth_patterns Dictionary: String -> String; optional

An optional dict mapping host names to custom authorization patterns. If a URL's host name is present in this dict the value will be used as a pattern when generating the authorization header for the http request. This enables the use of custom authorization schemes used in a lot of common cloud storage providers. The pattern currently supports 2 tokens: <login> and <password>, which are replaced with their equivalent value in the netrc file for the same host name. After formatting, the result is set as the value for the Authorization field of the HTTP request. Example attribute and netrc for a http download to an oauth2 enabled API using a bearer token: 

auth_patterns = {
    "storage.cloudprovider.com": "Bearer <password>"
}
netrc: 
machine storage.cloudprovider.com
        password RANDOM-TOKEN
The final HTTP request would have the following header: 
Authorization: Bearer RANDOM-TOKEN

canonical_id String; optional

A canonical id of the archive downloaded. If specified and non-empty, bazel will not take the archive from cache, unless it was added to the cache by a request with the same canonical id.

netrc String; optional

Location of the .netrc file to use for authentication

sha256 String; optional

The expected SHA-256 of the file downloaded.

url String; optional

The URL to fetch the jar from. It must end in `.jar`.

urls List of strings; optional

A list of URLS the jar can be fetched from. They have to end in `.jar`.