Create node_cache module for npm caching.

scripts/lib/node_cache.py

@@ -0,0 +1,60 @@
+from __future__ import print_function
+
+import os
+import hashlib
+from os.path import dirname, abspath
+
+if False:
+    from typing import Optional, List, Tuple
+
+from scripts.lib.zulip_tools import subprocess_text_output, run
+
+ZULIP_PATH = dirname(dirname(dirname(abspath(__file__))))
+NPM_CACHE_PATH = "/srv/zulip-npm-cache"
+
+if 'TRAVIS' in os.environ:
+    # In Travis CI, we don't have root access
+    NPM_CACHE_PATH = "/home/travis/zulip-npm-cache"
+
+def setup_node_modules(npm_args=None, stdout=None, stderr=None, copy_modules=False):
+    # type: (Optional[List[str]], Optional[str], Optional[str], Optional[bool]) -> None
+    sha1sum = hashlib.sha1()
+    sha1sum.update(subprocess_text_output(['cat', 'package.json']).encode('utf8'))
+    sha1sum.update(subprocess_text_output(['npm', '--version']).encode('utf8'))
+    sha1sum.update(subprocess_text_output(['node', '--version']).encode('utf8'))
+    if npm_args is not None:
+        sha1sum.update(''.join(sorted(npm_args)).encode('utf8'))
+
+    npm_cache = os.path.join(NPM_CACHE_PATH, sha1sum.hexdigest())
+    cached_node_modules = os.path.join(npm_cache, 'node_modules')
+    success_stamp = os.path.join(cached_node_modules, '.success-stamp')
+    # Check if a cached version already exists
+    if not os.path.exists(success_stamp):
+        do_npm_install(npm_cache, npm_args or [], stdout, stderr, copy_modules)
+
+    print("Using cached node modules from %s" % (cached_node_modules,))
+    cmds = [
+        ['rm', '-rf', 'node_modules'],
+        ["sudo", "ln", "-nsf", cached_node_modules, 'node_modules'],
+        ['touch', success_stamp],
+    ]
+    for cmd in cmds:
+        run(cmd, stdout=stdout, stderr=stderr)
+
+def do_npm_install(target_path, npm_args, stdout=None, stderr=None, copy_modules=False):
+    # type: (str, List[str], Optional[str], Optional[str], Optional[bool]) -> None
+    cmds = [
+        ["sudo", "rm", "-rf", target_path],
+        ['sudo', 'mkdir', '-p', target_path],
+        ["sudo", "chown", "{}:{}".format(os.getuid(), os.getgid()), target_path],
+        ['cp', 'package.json', target_path],
+    ]
+    if copy_modules:
+        print("Cached version not found! Copying node modules.")
+        cmds.append(["mv", "node_modules", target_path])
+    else:
+        print("Cached version not found! Installing node modules.")
+        cmds.append(['npm', 'install'] + npm_args + ['--prefix', target_path])
+
+    for cmd in cmds:
+        run(cmd, stdout=stdout, stderr=stderr)