NODE_BUILD_MIRROR_CMD generate's mirror URL

Not all mirrors will use the identical scheme of matching the nodejs.org url structure with `/dist` omitted. Now users may specify `NODE_BUILD_MIRROR_CMD` to be the name of a command or function which constructs the full mirrored package URL when given the original package URL and checksum as arguments. If omitted, the default scheme is used wherein NODE_BUILD_MIRROR_URL is substituted for `https://nodejs.org/dist/` The presence of *either* NODE_BUILD_MIRROR_URL or NODE_BUILD_MIRROR_CMD is sufficient to trigger a mirror attempt.

Author: jasonkarns

README.md

@@ -132,6 +132,8 @@ You can set certain environment variables to control the build process.
  built. By default, this is a subdirectory of `TMPDIR`.
 * `NODE_BUILD_CACHE_PATH`, if set, specifies a directory to use for caching
  downloaded package files.
+* `NODE_BUILD_MIRROR_CMD` provide a command to construct the package mirror
+ URL.
 * `NODE_BUILD_MIRROR_URL` select a mirror from which to download packages
  instead of their original source URLs.
 * `NODE_BUILD_SKIP_MIRROR`, if set, forces node-build to download packages from
@@ -182,8 +184,11 @@ definition. (All bundled definitions include checksums.)
 
 You can point node-build to another mirror by specifying the
 `NODE_BUILD_MIRROR_URL` environment variable--useful if you'd like to run your
-own local mirror, for example. Package mirror URLs are constructed by joining
-this variable with the SHA2 checksum of the package file.
+own local mirror, for example. Package mirror URLs are constructed by invoking
+`NODE_BUILD_MIRROR_CMD` with two arguments: `package_url` and `checksum`. The
+provided command should print the desired mirror's package URL. If
+`NODE_BUILD_MIRROR_CMD` is unset, package mirror URL construction defaults to
+simply replacing `https://nodejs.org/dist` with `NODE_BUILD_MIRROR_URL`.
 
 If you don't have an SHA2 program installed, node-build will skip the download
 mirror and use official URLs instead. You can force node-build to bypass the

bin/node-build

@@ -202,6 +202,13 @@ matches_platform() {
  [ "${platform[2]}-${platform[0]}" = "$match" ]
 }
 
+mirror() {
+ local package_url="$1"
+ local checksum="$2"
+
+ echo "${package_url/https:\/\/nodejs.org\/dist/$NODE_BUILD_MIRROR_URL}"
+}
+
 try_binary(){
  [ -n "$BINARY_URL" ] && [ -z "$SKIP_BINARY" ] && [ -z "$BINARY_ATTEMPT" ]
 }
@@ -443,8 +450,8 @@ fetch_tarball() {
  checksum="${package_url#*#}"
  package_url="${package_url%%#*}"
 
- if [ -n "$NODE_BUILD_MIRROR_URL" ]; then
- mirror_url="${package_url/https:\/\/nodejs.org\/dist/$NODE_BUILD_MIRROR_URL}"
+ if [ -z "$NODE_BUILD_SKIP_MIRROR" ]; then
+ mirror_url="$("${NODE_BUILD_MIRROR_CMD:=mirror}" $package_url $checksum 2>&4)" || unset mirror_url
  fi
  fi
 
@@ -466,9 +473,7 @@ fetch_tarball() {
  fi
 
  if ! reuse_existing_tarball "$package_filename" "$checksum"; then
- local tarball_filename=$(basename $package_url)
- echo "Downloading ${tarball_filename}..." >&2
- http head "$mirror_url" &&
+ echo "Downloading $(basename $package_url)..." >&2
  download_tarball "$mirror_url" "$package_filename" "$checksum" ||
  download_tarball "$package_url" "$package_filename" "$checksum"
  fi
@@ -905,14 +910,11 @@ WGET_OPTS="${NODE_BUILD_WGET_OPTS} ${IPV4+--inet4-only} ${IPV6+--inet6-only}"
 
 NODE_BUILD_MIRROR_URL="${NODE_BUILD_MIRROR_URL%/}"
 
-if ! has_checksum_support compute_sha2; then
+if ! has_checksum_support compute_sha2 ||
+ { [ -z "$NODE_BUILD_MIRROR_URL" ] && [ -z "$NODE_BUILD_MIRROR_CMD" ]; } then
  NODE_BUILD_SKIP_MIRROR=true
 fi
 
-if [ -n "$NODE_BUILD_SKIP_MIRROR" ] || [ -z "$NODE_BUILD_MIRROR_URL" ]; then
- unset NODE_BUILD_MIRROR_URL
-fi
-
 SEED="$(date "+%Y%m%d%H%M%S").$$"
 LOG_PATH="${TMP}/node-build.${SEED}.log"
 NODE_BIN="${PREFIX_PATH}/bin/node"

test/mirror.bats

@@ -4,6 +4,7 @@ load test_helper
 export NODE_BUILD_SKIP_MIRROR=
 export NODE_BUILD_CACHE_PATH=
 export NODE_BUILD_MIRROR_URL=http://mirror.example.com
+export NODE_BUILD_MIRROR_CMD=mirror_stub
 export NODE_BUILD_CURL_OPTS=
 
 setup() {
@@ -15,7 +16,6 @@ setup() {
  stub curl "-q -o * -*S* http://example.com/* : cp $FIXTURE_ROOT/\${5##*/} \$3"
 
  install_fixture definitions/without-checksum
- echo "$output" >&2
 
  assert_success
  assert [ -x "${INSTALL_ROOT}/bin/package" ]
@@ -43,14 +43,15 @@ setup() {
  local mirror_url="${NODE_BUILD_MIRROR_URL}/$checksum"
 
  stub shasum true "echo $checksum"
- stub curl "-*I* $mirror_url : true" \
-  "-q -o * -*S* $mirror_url : cp $FIXTURE_ROOT/package-1.0.0.tar.gz \$3"
+ stub curl "-q -o * -*S* $mirror_url : cp $FIXTURE_ROOT/package-1.0.0.tar.gz \$3"
+ stub mirror_stub ": echo $mirror_url"
 
  install_fixture definitions/with-checksum
 
  assert_success
  assert [ -x "${INSTALL_ROOT}/bin/package" ]
 
+ unstub mirror_stub
  unstub curl
  unstub shasum
 }
@@ -61,14 +62,16 @@ setup() {
  local mirror_url="${NODE_BUILD_MIRROR_URL}/$checksum"
 
  stub shasum true "echo $checksum"
- stub curl "-*I* $mirror_url : false" \
- "-q -o * -*S* http://example.com/* : cp $FIXTURE_ROOT/\${5##*/} \$3"
+ stub curl "-q -o * -*S* $mirror_url : false"\
+ "-q -o * -*S* http://example.com/* : cp $FIXTURE_ROOT/\${5##*/} \$3"
+ stub mirror_stub ": echo $mirror_url"
 
  install_fixture definitions/with-checksum
 
  assert_success
  assert [ -x "${INSTALL_ROOT}/bin/package" ]
 
+ unstub mirror_stub
  unstub curl
  unstub shasum
 }
@@ -79,16 +82,16 @@ setup() {
  local mirror_url="${NODE_BUILD_MIRROR_URL}/$checksum"
 
  stub shasum true "echo invalid" "echo $checksum"
- stub curl "-*I* $mirror_url : true" \
- "-q -o * -*S* $mirror_url : cp $FIXTURE_ROOT/package-1.0.0.tar.gz \$3" \
+ stub curl "-q -o * -*S* $mirror_url : cp $FIXTURE_ROOT/package-1.0.0.tar.gz \$3" \
  "-q -o * -*S* http://example.com/* : cp $FIXTURE_ROOT/\${5##*/} \$3"
+ stub mirror_stub ": echo $mirror_url"
 
  install_fixture definitions/with-checksum
- echo "$output" >&2
 
  assert_success
  assert [ -x "${INSTALL_ROOT}/bin/package" ]
 
+ unstub mirror_stub
  unstub curl
  unstub shasum
 }