From be8a0859a92d131cc317029142d4ed528f0d1767 Mon Sep 17 00:00:00 2001
From: Mihai Parparita <mihai@tailscale.com>
Date: Thu, 21 Jul 2022 17:58:50 -0700
Subject: [PATCH] cmd/tsconnect: pin yarn and node

Adds a tool/yarn helper script that uses specific versions of yarn and
node, downloading them if necessary.

Modeled after tool/go (and the yarn and node Redo scripts from the
corp repo).

Also allows the path to yarn to be overidden (in case the user does not
want to use this script) and always pipes yarn output (to make debugging
and viewing of process easier).

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
---
 cmd/tsconnect/common.go    |  9 ++---
 cmd/tsconnect/tsconnect.go |  5 ++-
 tool/node.rev              |  1 +
 tool/yarn                  | 79 ++++++++++++++++++++++++++++++++++++++
 tool/yarn.rev              |  1 +
 5 files changed, 88 insertions(+), 7 deletions(-)
 create mode 100644 tool/node.rev
 create mode 100755 tool/yarn
 create mode 100644 tool/yarn.rev

diff --git a/cmd/tsconnect/common.go b/cmd/tsconnect/common.go
index b77402a44..c085996fe 100644
--- a/cmd/tsconnect/common.go
+++ b/cmd/tsconnect/common.go
@@ -97,11 +97,10 @@ func buildWasm(dev bool) error {
 // installJSDeps installs the JavaScript dependencies specified by package.json
 func installJSDeps() error {
 	log.Printf("Installing JS deps...\n")
-	stdoutStderr, err := exec.Command("yarn").CombinedOutput()
-	if err != nil {
-		log.Printf("yarn failed: %s", stdoutStderr)
-	}
-	return err
+	cmd := exec.Command(*yarnPath)
+	cmd.Stdout = os.Stdout
+	cmd.Stderr = os.Stderr
+	return cmd.Run()
 }
 
 // EsbuildMetadata is the subset of metadata struct (described by
diff --git a/cmd/tsconnect/tsconnect.go b/cmd/tsconnect/tsconnect.go
index d5d152d2f..3f48987d1 100644
--- a/cmd/tsconnect/tsconnect.go
+++ b/cmd/tsconnect/tsconnect.go
@@ -18,8 +18,9 @@ import (
 )
 
 var (
-	addr    = flag.String("addr", ":9090", "address to listen on")
-	distDir = flag.String("distdir", "./dist", "path of directory to place build output in")
+	addr     = flag.String("addr", ":9090", "address to listen on")
+	distDir  = flag.String("distdir", "./dist", "path of directory to place build output in")
+	yarnPath = flag.String("yarnpath", "../../tool/yarn", "path yarn executable used to install JavaScript dependencies")
 )
 
 func main() {
diff --git a/tool/node.rev b/tool/node.rev
new file mode 100644
index 000000000..0baffb7e2
--- /dev/null
+++ b/tool/node.rev
@@ -0,0 +1 @@
+16.4.1
diff --git a/tool/yarn b/tool/yarn
new file mode 100755
index 000000000..4f70e4106
--- /dev/null
+++ b/tool/yarn
@@ -0,0 +1,79 @@
+#!/bin/sh
+#
+# This script acts like the "yarn" command, but uses Tailscale's
+# currently-desired version, downloading it (and node) first if necessary.
+
+set -eu
+
+NODE_DIR="$HOME/.cache/tailscale-node"
+read -r YARN_REV < "$(dirname "$0")/yarn.rev"
+YARN_DIR="$HOME/.cache/tailscale-yarn"
+# This works for linux and darwin, which is sufficient
+# (we do not build for other targets).
+OS=$(uname -s | tr A-Z a-z)
+ARCH="$(uname -m)"
+if [ "$ARCH" = "aarch64" ]; then
+    # Go uses the name "arm64".
+    ARCH="arm64"
+elif [ "$ARCH" = "x86_64" ]; then
+    # Go uses the name "amd64".
+    ARCH="amd64"
+fi
+
+install_node() {
+    read -r NODE_REV < "$(dirname "$0")/node.rev"
+    NODE_URL="https://nodejs.org/dist/v${NODE_REV}/node-v${NODE_REV}-${OS}-${ARCH}.tar.gz"
+    install_tool "node" $NODE_REV $NODE_DIR $NODE_URL
+}
+
+install_yarn() {
+    YARN_URL="https://github.com/yarnpkg/yarn/releases/download/v$YARN_REV/yarn-v$YARN_REV.tar.gz"
+    install_tool "yarn" $YARN_REV $YARN_DIR $YARN_URL
+}
+
+install_tool() {
+    TOOL=$1
+    REV=$2
+    TOOLCHAIN=$3
+    URL=$4
+
+    archive="$TOOLCHAIN-$REV.tar.gz"
+    mark="$TOOLCHAIN.extracted"
+    extracted=
+    [ ! -e "$mark" ] || read -r extracted junk <$mark
+
+    if [ "$extracted" = "$REV" ] && [ -e "$TOOLCHAIN/bin/$TOOL" ]; then
+        # Already extracted, continue silently
+        return 0
+    fi
+
+    rm -f "$archive.new" "$TOOLCHAIN.extracted"
+    if [ ! -e "$archive" ]; then
+            log "Need to download $TOOL '$REV'."
+            curl -f -L -o "$archive.new" $URL
+            rm -f "$archive"
+            mv "$archive.new" "$archive"
+    fi
+
+    log "Extracting $TOOL '$REV' into '$TOOLCHAIN'." >&2
+    rm -rf "$TOOLCHAIN"
+    mkdir -p "$TOOLCHAIN"
+    (cd "$TOOLCHAIN" && tar --strip-components=1 -xf "$archive")
+    echo "$REV" >$mark
+}
+
+log() {
+    echo "$@" >&2
+}
+
+if [ "${YARN_REV}" = "SKIP" ] ||
+   [ "${OS}" != "darwin" -a "${OS}" != "linux" ] ||
+   [ "${ARCH}" != "amd64" -a "${ARCH}" != "arm64" ]; then
+    log "Using existing yarn (`which yarn`)."
+    exec yarn "$@"
+fi
+
+install_node
+install_yarn
+
+exec /usr/bin/env PATH="$NODE_DIR/bin:$PATH" "$YARN_DIR/bin/yarn" "$@"
diff --git a/tool/yarn.rev b/tool/yarn.rev
new file mode 100644
index 000000000..de5856e86
--- /dev/null
+++ b/tool/yarn.rev
@@ -0,0 +1 @@
+1.22.19