Improve release automation

Signed-off-by: Chris Frantz <[email protected]>

BUILD.bazel

@@ -16,12 +16,15 @@ release(
         "@mxe_src//:mxe-binaries": "MXE mingw64 compiler",
         "@qemu_src//:qemu-binaries": "QEMU system emulator",
     },
+    env = {
+        "BASE_URL": "https://github.com/cfrantz/crt",
+    },
     script = """(
         cd "${BUILD_WORKSPACE_DIRECTORY}"
-        envsubst \
+        # Apparently envsubst can't handle bash arrays or dicts.
+        SHA256=${DIGEST[mxe-binaries.tar.xz]} envsubst \
                 <toolchains/gcc_mxe_mingw64/repository.bzl.template \
                 >toolchains/gcc_mxe_mingw64/repository.bzl
-        # Apparently envsubst can't handle bash arrays or dicts.
         SHA256=${DIGEST[qemu-binaries.tar.xz]} envsubst \
                 <third_party/qemu/repos.bzl.template \
                 >third_party/qemu/repos.bzl

third_party/github/release.template.bash

@@ -6,6 +6,7 @@ ARTIFACTS=(@@ARTIFACTS@@)
 FILES=(@@FILES@@)
 GH=@@GH@@
 REMOTE="@@REMOTE@@"
+@@ENV@@
 
 BRANCH=$(cd "$BUILD_WORKSPACE_DIRECTORY" && git branch --show-current)
 RELEASE_TAG=$(cd "$BUILD_WORKSPACE_DIRECTORY" && git describe --abbrev=0 --tags)

third_party/github/rules.bzl

@@ -8,13 +8,15 @@ def _release_impl(ctx):
         runfiles.extend(files)
         artifacts.append("'{}#{}'".format(files[0].short_path, v))
 
+    env = "\n".join(["export {}=\"{}\"".format(k, v) for k, v in ctx.attr.env.items()])
     runner = ctx.actions.declare_file(ctx.label.name + ".bash")
     ctx.actions.expand_template(
         template = ctx.file._runner,
         output = runner,
         is_executable = True,
         substitutions = {
             "@@ARTIFACTS@@": " ".join(artifacts),
+            "@@ENV@@": env,
             "@@FILES@@": " ".join([f.short_path for f in runfiles]),
             "@@REMOTE@@": ctx.attr.remote,
             "@@SCRIPT@@": ctx.attr.script,
@@ -42,6 +44,9 @@ release = rule(
         "script": attr.string(
             doc = "Script operation to perform before the github release operation",
         ),
+        "env": attr.string_dict(
+            doc = "Additional environment variables for the script",
+        ),
         "_gh": attr.label(
             default = "@com_github_gh//:gh",
             cfg = "exec",

third_party/qemu/repos.bzl.template

@@ -14,9 +14,7 @@ def qemu_src_repos():
 def qemu_binary_repos():
     http_archive(
         name = "qemu",
-        urls = [
-            "https://github.com/cfrantz/crt/releases/download/${RELEASE_TAG}/qemu-binaries.tar.xz",
-        ],
+        url = "${BASE_URL}/releases/download/${RELEASE_TAG}/qemu-binaries.tar.xz",
         sha256 = "${SHA256}",
         build_file = Label("//third_party/qemu:BUILD.qemu.bazel"),
         strip_prefix = "qemu",

toolchains/gcc_mxe_mingw64/repository.bzl.template

@@ -3,6 +3,7 @@ load("@crt//config:repo.bzl", "compiler_repository")
 def gcc_mxe_mingw64_repos():
     compiler_repository(
         name = "gcc_mxe_mingw64_files",
-        url = "https://github.com/cfrantz/crt/releases/download/${RELEASE_TAG}/mxe-binaries.tar.xz",
+        url = "${BASE_URL}/releases/download/${RELEASE_TAG}/mxe-binaries.tar.xz",
+        sha256 = "${SHA256}",
         strip_prefix = "mxe",
     )