Migrate to python 3

Given that on most systems Python is still linked to the Python 2.7,
switch explicitly to using Python 3.

Python 2.7 was discontinued on January 1, 2020: [1].

Moreover, there is PEP recommending to use python3 in the shebang: [2].

[1] https://www.python.org/doc/sunset-python-2
[2] https://www.python.org/dev/peps/pep-0394

Change-Id: Ia4ca09e65a451868de738d3dba6f62fdd7c5e50d
(cherry picked from commit 2b5fe095f9431e995b23d3517a052fa7f4c36638)

20 files changed, 28 insertions, 28 deletions

diff --git a/.bazelrc b/.bazelrc
index bf3aa6c3b0..e560f2397a 100644
--- a/.bazelrc
+++ b/.bazelrc
@@ -1,4 +1,4 @@
-build --workspace_status_command="python ./tools/workspace_status.py" --strategy=Closure=worker
+build --workspace_status_command="python3 ./tools/workspace_status.py" --strategy=Closure=worker
 build --repository_cache=~/.gerritcodereview/bazel-cache/repository
 build --action_env=PATH
 build --disk_cache=~/.gerritcodereview/bazel-cache/cas
diff --git a/Documentation/dev-bazel.txt b/Documentation/dev-bazel.txt
index 2a8b7c17f0..10ee7616bc 100644
--- a/Documentation/dev-bazel.txt
+++ b/Documentation/dev-bazel.txt
@@ -7,7 +7,7 @@ To build Gerrit from source, you need:
 
 * A Linux or macOS system (Windows is not supported at this time)
 * A JDK for Java 8|9|10|11|...
-* Python 2 or 3
+* Python 3
 * link:https://github.com/nodesource/distributions/blob/master/README.md[Node.js (including npm)]
 * Bower (`sudo npm install -g bower`)
 * link:https://docs.bazel.build/versions/master/install.html[Bazel] -launched with
diff --git a/Documentation/replace_macros.py b/Documentation/replace_macros.py
index aaa9223bf0..f2702313db 100755
--- a/Documentation/replace_macros.py
+++ b/Documentation/replace_macros.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # coding=utf-8
 # Copyright (C) 2013 The Android Open Source Project
 #
diff --git a/contrib/check-valid-commit.py b/contrib/check-valid-commit.py
index 763ae3e062..bb018f9bcf 100755
--- a/contrib/check-valid-commit.py
+++ b/contrib/check-valid-commit.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 from __future__ import print_function
 
diff --git a/contrib/git-push-review b/contrib/git-push-review
index b995fc25a6..5a7f664bf3 100755
--- a/contrib/git-push-review
+++ b/contrib/git-push-review
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2014 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/contrib/populate-fixture-data.py b/contrib/populate-fixture-data.py
index 4c6769cf3e..e51e29d0eb 100755
--- a/contrib/populate-fixture-data.py
+++ b/contrib/populate-fixture-data.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2016 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/tools/bzl/js.bzl b/tools/bzl/js.bzl
index b428a2d903..9baa30c156 100644
--- a/tools/bzl/js.bzl
+++ b/tools/bzl/js.bzl
@@ -26,7 +26,7 @@ def _npm_binary_impl(ctx):
     else:
         fail("repository %s not in {%s,%s}" % (repository, GERRIT, NPMJS))
 
-    python = ctx.which("python")
+    python = ctx.which("python3")
     script = ctx.path(ctx.attr._download_script)
 
     args = [python, script, "-o", dest, "-u", url, "-v", sha1]
@@ -49,7 +49,7 @@ ComponentInfo = provider()
 
 # for use in repo rules.
 def _run_npm_binary_str(ctx, tarball, args):
-    python_bin = ctx.which("python")
+    python_bin = ctx.which("python3")
     return " ".join([
         str(python_bin),
         str(ctx.path(ctx.attr._run_npm)),
@@ -63,7 +63,7 @@ def _bower_archive(ctx):
     version_name = "%s__version.json" % ctx.name
 
     cmd = [
-        ctx.which("python"),
+        ctx.which("python3"),
         ctx.path(ctx.attr._download_bower),
         "-b",
         "%s" % _run_npm_binary_str(ctx, ctx.attr._bower_archive, []),
@@ -318,7 +318,7 @@ def _bundle_impl(ctx):
     app_path = app_path[app_path.index(pkg_dir) + len(pkg_dir):]
 
     hermetic_npm_binary = " ".join([
-        "python",
+        "python3",
         "$p/" + ctx.file._run_npm.path,
         "$p/" + ctx.file._bundler_archive.path,
         "--inline-scripts",
@@ -369,7 +369,7 @@ def _bundle_impl(ctx):
 
     if ctx.attr.split:
         hermetic_npm_command = "export PATH && " + " ".join([
-            "python",
+            "python3",
             ctx.file._run_npm.path,
             ctx.file._crisper_archive.path,
             "--script-in-head=false",
diff --git a/tools/bzl/license-map.py b/tools/bzl/license-map.py
index 2779130f47..e23331852d 100644
--- a/tools/bzl/license-map.py
+++ b/tools/bzl/license-map.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # reads bazel query XML files, to join target names with their licenses.
 
diff --git a/tools/bzl/license.bzl b/tools/bzl/license.bzl
index 5a6bf7fa63..ec89c41608 100644
--- a/tools/bzl/license.bzl
+++ b/tools/bzl/license.bzl
@@ -25,7 +25,7 @@ def license_map(name, targets = [], opts = [], **kwargs):
     # post process the XML into our favorite format.
     native.genrule(
         name = "gen_license_txt_" + name,
-        cmd = "python $(location //tools/bzl:license-map.py) %s %s > $@" % (" ".join(opts), " ".join(xmls)),
+        cmd = "python3 $(location //tools/bzl:license-map.py) %s %s > $@" % (" ".join(opts), " ".join(xmls)),
         outs = [name + ".gen.txt"],
         tools = tools,
         **kwargs
diff --git a/tools/bzl/maven_jar.bzl b/tools/bzl/maven_jar.bzl
index 5bc181b24a..fa7fbf78e8 100644
--- a/tools/bzl/maven_jar.bzl
+++ b/tools/bzl/maven_jar.bzl
@@ -154,7 +154,7 @@ def _maven_jar_impl(ctx):
     binjar_path = ctx.path("/".join(["jar", binjar]))
     binurl = url + ".jar"
 
-    python = ctx.which("python")
+    python = ctx.which("python3")
     script = ctx.path(ctx.attr._download_script)
 
     args = [python, script, "-o", binjar_path, "-u", binurl]
diff --git a/tools/download_file.py b/tools/download_file.py
index 936bcef32c..2af2c0722c 100755
--- a/tools/download_file.py
+++ b/tools/download_file.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2013 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/tools/eclipse/project.py b/tools/eclipse/project.py
index 9915a6e213..77dc226fd7 100755
--- a/tools/eclipse/project.py
+++ b/tools/eclipse/project.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2016 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/tools/js/download_bower.py b/tools/js/download_bower.py
index d541b565a9..2a75fc16ed 100755
--- a/tools/js/download_bower.py
+++ b/tools/js/download_bower.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2015 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/tools/js/npm_pack.py b/tools/js/npm_pack.py
index 57f31661c5..33b38a0280 100755
--- a/tools/js/npm_pack.py
+++ b/tools/js/npm_pack.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2015 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/tools/js/run_npm_binary.py b/tools/js/run_npm_binary.py
index bdee5ab489..31f8a54113 100644
--- a/tools/js/run_npm_binary.py
+++ b/tools/js/run_npm_binary.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2015 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/tools/maven/mvn.py b/tools/maven/mvn.py
index 60e9f15608..4ed5bf95d5 100755
--- a/tools/maven/mvn.py
+++ b/tools/maven/mvn.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2013 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/tools/util_test.py b/tools/util_test.py
index 1a389f552c..ab1133b22e 100644
--- a/tools/util_test.py
+++ b/tools/util_test.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2013 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/tools/version.py b/tools/version.py
index 2326757a05..d02fc26c76 100755
--- a/tools/version.py
+++ b/tools/version.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Copyright (C) 2014 The Android Open Source Project
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
diff --git a/tools/workspace_status.py b/tools/workspace_status.py
index 86df519ed5..0dc4a48bfe 100644
--- a/tools/workspace_status.py
+++ b/tools/workspace_status.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # This script will be run by bazel when the build process starts to
 # generate key-value information that represents the status of the
diff --git a/tools/workspace_status_release.py b/tools/workspace_status_release.py
index 36535fb70f..b3e72ff76a 100644
--- a/tools/workspace_status_release.py
+++ b/tools/workspace_status_release.py
@@ -1,4 +1,4 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 # This is a variant of the `workspace_status.py` script that in addition to
 # plain `git describe` implements a few heuristics to arrive at more to the
@@ -9,7 +9,7 @@
 #
 # To use it, simply add
 #
-#   --workspace_status_command="python ./tools/workspace_status_release.py"
+#   --workspace_status_command="python3 ./tools/workspace_status_release.py"
 #
 # to your bazel command. So for example instead of
 #
@@ -17,11 +17,11 @@
 #
 # use
 #
-#   bazel build --workspace_status_command="python ./tools/workspace_status_release.py" release.war
+#   bazel build --workspace_status_command="python3 ./tools/workspace_status_release.py" release.war
 #
 # Alternatively, you can add
 #
-#   build --workspace_status_command="python ./tools/workspace_status_release.py"
+#   build --workspace_status_command="python3 ./tools/workspace_status_release.py"
 #
 # to `.bazelrc` in your home directory.
 #
@@ -150,7 +150,7 @@ def print_stamps_for_cwd(name, template):
         'tools', 'workspace_status_release.py')
     if os.path.isfile(workspace_status_script):
         # directory has own workspace_status_command, so we use stamps from that
-        for line in run(["python", workspace_status_script]).split('\n'):
+        for line in run(["python3", workspace_status_script]).split('\n'):
             if re.search("^STABLE_[a-zA-Z0-9().:@/_ -]*$", line):
                 print(line)
     else: