Build C++ project with Bazel offline (without internet connection)

user_16300322 0
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I try to build the Bazel C++ Build Tutorial from the Bazel homepage (Getting Started) with this command but without any connection to the internet: bazel build //main:hello-world

The Jenkins Server will not have any connection to the internet so I can't do prefetching or similar. Is there a way how to prepare my C++ project on another computer and transfer the dependencies to the Jenkins Server to do it offline? How? I would just need what I got from the following error message respectively get the tutorial running:

Extracting Bazel installation...
Starting local Bazel server and connecting to it...
INFO: Repository rules_cc instantiated at:
  /DEFAULT.WORKSPACE.SUFFIX:267:6: in <toplevel>
  C:/users/XXX/_bazel_XXX/dq2p42jq/external/bazel_tools/tools/build_defs/repo/utils.bzl:201:18: in maybe
Repository rule http_archive defined at:
  C:/users/XXX/_bazel_XXX/dq2p42jq/external/bazel_tools/tools/build_defs/repo/http.bzl:336:31: in <toplevel>
WARNING: Download from https://mirror.bazel.build/github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip failed: class java.io.IOException Unable to tunnel through proxy. Proxy returns "HTTP/1.1 501 Not Implemented"
WARNING: Download from https://github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip failed: class java.io.IOException Unable to tunnel through proxy. Proxy returns "HTTP/1.1 501 Not Implemented"
ERROR: An error occurred during the fetch of repository 'rules_cc':
   Traceback (most recent call last):
        File "C:/users/XXX/_bazel_XXX/dq2p42jq/external/bazel_tools/tools/build_defs/repo/http.bzl", line 111, column 45, in _http_archive_impl
                download_info = ctx.download_and_extract(
Error in download_and_extract: java.io.IOException: Error downloading [https://mirror.bazel.build/github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip, https://github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip] to C:/users/XXX/_bazel_XXX/dq2p42jq/external/rules_cc/temp1363696983472254851/b1c40e1de81913a3c40e5948f78719c28152486d.zip: Unable to tunnel through proxy. Proxy returns "HTTP/1.1 501 Not Implemented"
ERROR: Error fetching repository: Traceback (most recent call last):
        File "C:/users/XXX/_bazel_XXX/dq2p42jq/external/bazel_tools/tools/build_defs/repo/http.bzl", line 111, column 45, in _http_archive_impl
                download_info = ctx.download_and_extract(
Error in download_and_extract: java.io.IOException: Error downloading [https://mirror.bazel.build/github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip, https://github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip] to C:/users/XXX/_bazel_XXX/dq2p42jq/external/rules_cc/temp1363696983472254851/b1c40e1de81913a3c40e5948f78719c28152486d.zip: Unable to tunnel through proxy. Proxy returns "HTTP/1.1 501 Not Implemented"
ERROR: Skipping '//main:hello-world': no such package '@rules_cc//cc': java.io.IOException: Error downloading [https://mirror.bazel.build/github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip, https://github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip] to C:/users/XXX/_bazel_XXX/dq2p42jq/external/rules_cc/temp1363696983472254851/b1c40e1de81913a3c40e5948f78719c28152486d.zip: Unable to tunnel through proxy. Proxy returns "HTTP/1.1 501 Not Implemented"
WARNING: Target pattern parsing failed.
ERROR: no such package '@rules_cc//cc': java.io.IOException: Error downloading [https://mirror.bazel.build/github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip, https://github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip] to C:/users/XXX/_bazel_XXX/dq2p42jq/external/rules_cc/temp1363696983472254851/b1c40e1de81913a3c40e5948f78719c28152486d.zip: Unable to tunnel through proxy. Proxy returns "HTTP/1.1 501 Not Implemented"
INFO: Elapsed time: 30.974s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (0 packages loaded)
    currently loading: main

Update: I tried prefetching and it doesn't work. What I did:

  1. run bazel fetch //...
  2. Copy the prefetched data from bazel info output_base directory from local to jenkins server (I had to recreate one sym link to the install dir).
  3. I run bazel build --fetch=false //main:hello-world on jenkins without refatching. Now I get following error:
Loading: 
Loading: 0 packages loaded
WARNING: /DEFAULT.WORKSPACE:1:17: External repository 'bazel_tools' is not up-to-date and fetching is disabled. To update, run the build without the '--nofetch' command line option.
ERROR: error loading package '': Every .bzl file must have a corresponding package, but '@bazel_tools//tools/build_defs/repo:http.bzl' does not have one. Please create a BUILD file in the same or any parent directory. Note that this BUILD file does not need to do anything except exist.
INFO: Elapsed time: 0.298s
INFO: 0 processes.
FAILED: Build did NOT complete successfully (0 packages loaded)
bazel offline build c++
2 Answers

I found one solution for offline building a simple C++ projects with bazel. First you have to download the rules_cc and rules_java libs, because these where the external dependent libs in the simple Bazel C++ tutorial project. I found no release for rules_cc so I downloaded the zip file from the url which was mentioned in the error message on the console when I was trying to use bazel build offline: https://mirror.bazel.build/github.com/bazelbuild/rules_cc/archive/b1c40e1de81913a3c40e5948f78719c28152486d.zip. The sha key was also mentioned in the error message when you try to use the lib locally with a wrong sha key (see below). The rules_java lib can be downloaded here: https://github.com/bazelbuild/rules_java/releases. The WORKSPACE specification is also mentioned there.

Then you have to add the following to your WORKSPACE file. Be aware, that you have to point to your local copy of the archive files for rules_cc and rules_java. And for rules_cc you have to mention in strip_prefix the root path of the archive file (the first and only root directory in the .zip file). The rules_java has no root directory:

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

http_archive(
    name = "rules_cc",
    urls = ["file:C:/tmp/b1c40e1de81913a3c40e5948f78719c28152486d.zip"],
    strip_prefix = "rules_cc-b1c40e1de81913a3c40e5948f78719c28152486d",
    sha256 = "d0c573b94a6ef20ef6ff20154a23d0efcb409fb0e1ff0979cec318dfe42f0cdd",
)

http_archive(
    name = "rules_java",
    url = "file:C:/tmp/rules_java-4.0.0.tar.gz",
    sha256 = "34b41ec683e67253043ab1a3d1e8b7c61e4e8edefbcad485381328c934d072fe",
)
user_163003220

You can run bazel fetch //... to fetch data locally on the machine, which has access to the internet. Then you can just copy prefetched data: from bazel info output_base directory on your local PC to bazel info output_base in the jenkins job.

user_46386040
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