What is RULES_JVM_EXTERNAL_TAG and RULES_JVM_EXTERNAL_SHA in bazel WORKSPACE file?

Question

I'm trying to move to bazel from maven. I saw the tutorial in bazel documentation and it has a sample WORKSPACE file. link

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

RULES_JVM_EXTERNAL_TAG = "2.8"
RULES_JVM_EXTERNAL_SHA = "79c9850690d7614ecdb72d68394f994fef7534b292c4867ce5e7dec0aa7bdfad"

http_archive(
    name = "rules_jvm_external",
    strip_prefix = "rules_jvm_external-%s" % RULES_JVM_EXTERNAL_TAG,
    sha256 = RULES_JVM_EXTERNAL_SHA,
    url = "https://github.com/bazelbuild/rules_jvm_external/archive/%s.zip" % RULES_JVM_EXTERNAL_TAG,
)

Can someone please explain what is happening here? The rest of the sample WORKSPACE file given is self explanatory where we are telling what maven dependencies are required for the project. Thanks.

Answer 1

They refer to the release version for the rules_jvm_external project sources and the SHA256 checksum of the associated release .zip file.

https://github.com/bazelbuild/rules_jvm_external/releases