src: Port Go build wrapper from Shell to Python & support externaly defined build options

completion/meson.build

@@ -1,14 +1,14 @@
 generate_completions_program = find_program('generate_completions.py')
 
 if bash_completion.found()
-  bash_comp_dir = bash_completion.get_pkgconfig_variable('completionsdir')
+  bash_comp_dir = bash_completion.get_variable(pkgconfig: 'completionsdir')
 else
   bash_comp_dir = get_option('datadir') / 'bash-completion' / 'completions'
   message('bash-completion not found: using', get_option('prefix') / bash_comp_dir, 'as a falback install directory')
 endif
 
 if fish.found()
-  fish_comp_dir = fish.get_pkgconfig_variable('completionsdir')
+  fish_comp_dir = fish.get_variable(pkgconfig: 'completionsdir')
 else
   fish_comp_dir = get_option('datadir') / 'fish' / 'completions'
   message('fish not found: using', get_option('prefix') / fish_comp_dir, 'as a fallback install directory')

meson.build

@@ -37,33 +37,11 @@ if not skopeo.found()
     message('Running system tests requires Skopeo for OCI image manipulation.')
 endif
 
-install_subdir(
-  'test',
-  install_dir: join_paths(get_option('datadir'), meson.project_name()),
-  exclude_files: [
-    'system/libs/bats-assert/.git',
-    'system/libs/bats-assert/.gitignore',
-    'system/libs/bats-assert/.travis.yml',
-    'system/libs/bats-assert/package.json',
-    'system/libs/bats-support/.git',
-    'system/libs/bats-support/.gitignore',
-    'system/libs/bats-support/.travis.yml',
-    'system/libs/bats-support/package.json'
-    ],
-  exclude_directories: [
-    'system/libs/bats-assert/.git',
-    'system/libs/bats-assert/script',
-    'system/libs/bats-assert/test',
-    'system/libs/bats-support/.git',
-    'system/libs/bats-support/script',
-    'system/libs/bats-support/test'
-  ]
-)
-
 subdir('data')
 subdir('doc')
 subdir('profile.d')
 subdir('src')
+subdir('test')
 if get_option('install_completions')
   subdir('completion')
 endif

meson_options.txt

@@ -24,3 +24,9 @@ option(
   type: 'boolean',
   value: true,
 )
+
+option(
+  'go_build_flags',
+  description: 'Options passed to \'go build\' during build',
+  type: 'string',
+)

src/go-build-wrapper.py

@@ -0,0 +1,109 @@
+#!/usr/bin/env python3
+#
+# Copyright © 2022 Ondřej Míchal
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+#
+
+import os
+import shlex
+import subprocess
+import sys
+
+prog_name = os.path.basename(sys.argv[0])
+
+
+def get_canonical_libc_dirname(cc):
+    try:
+        libc_path = subprocess.run(
+            [cc, '--print-file-name=libc.so'],
+            capture_output=True, check=True, text=True).stdout.strip()
+    except subprocess.CalledProcessError as e:
+        print(f'{prog_name}: failed to read the path to libc.so', file=sys.stderr)
+        print(e.stderr, file=sys.stderr)
+        sys.exit(1)
+
+    libc_path_canonical = os.path.realpath(libc_path)
+
+    return os.path.dirname(libc_path_canonical)
+
+
+def create_rpath(libc_path_dirname):
+    return '/run/host' + libc_path_dirname
+
+
+def alter_dynamic_linker_path(dynamic_linker):
+    dynamic_linker_basename = os.path.basename(dynamic_linker)
+    dynamic_linker_canonical = os.path.realpath(dynamic_linker)
+    dynamic_linker_canonical_dirname = os.path.dirname(
+        dynamic_linker_canonical)
+
+    return f'/run/host{dynamic_linker_canonical_dirname}/{dynamic_linker_basename}'
+
+
+if len(sys.argv) != 8:
+    print('{}: wrong arguments'.format(prog_name), file=sys.stderr)
+    print('''Usage: {} [SOURCE DIR]
+                           [OUTPUT DIR]
+                           [VERSION]
+                           [C COMPILER]
+                           [DYNAMIC LINKER]
+                           [MIGRATION PATH FORCOREOS/TOOLBOX]
+                           [BUILD FLAGS]'''.format(prog_name), file=sys.stderr)
+    sys.exit(1)
+
+source_dir = sys.argv[1]
+output_dir = sys.argv[2]
+version = sys.argv[3]
+cc = sys.argv[4]
+dynamic_linker = sys.argv[5]
+# Boolean is passed from Meson as a string
+coreos_migration = True if sys.argv[6] == "true" else False
+build_flags = sys.argv[7]
+
+try:
+    os.chdir(source_dir)
+except OSError as e:
+    print(f'{prog_name}: failed to change directory to {source_dir}',
+          file=sys.stderr)
+    print(e, file=sys.stderr)
+    sys.exit(1)
+
+libc_path_dirname = get_canonical_libc_dirname(cc)
+dynamic_linker = alter_dynamic_linker_path(dynamic_linker)
+rpath = create_rpath(libc_path_dirname)
+
+# Write overriden binary values to a file for testing
+go_build_override_values_file = os.path.join(output_dir, 'go-build-overrides')
+with open(go_build_override_values_file, mode='w') as f:
+    f.write(f'{dynamic_linker} {rpath}')
+
+build_cmd = [
+    'go', 'build',
+    '-trimpath',
+    '-o', os.path.join(output_dir, 'toolbox')
+]
+
+if coreos_migration:
+    build_cmd.extend(['-tags', 'migration_path_for_coreos_toolbox'])
+
+if build_flags:
+    build_cmd.extend(shlex.split(build_flags))
+
+build_cmd.extend([
+    '-ldflags',
+    f'-extldflags \'-Wl,-dynamic-linker,{dynamic_linker} -Wl,-rpath,{rpath}\' -linkmode external -X github.com/containers/toolbox/pkg/version.currentVersion={version}'
+])
+
+go_build = subprocess.run(build_cmd)
+sys.exit(go_build.returncode)

src/meson.build

@@ -1,5 +1,4 @@
-go_build_wrapper_file = files('go-build-wrapper')
-go_build_wrapper_program = find_program('go-build-wrapper')
+go_build_wrapper_program = find_program('go-build-wrapper.py')
 
 meson_go_fmt_program = find_program('meson_go_fmt.py')
 
@@ -47,7 +46,7 @@ endif
 
 message('Host machine dynamic linker:', dynamic_linker)
 
-custom_target(
+toolbox = custom_target(
   'toolbox',
   build_by_default: true,
   command: [
@@ -58,16 +57,18 @@ custom_target(
     cc.cmd_array().get(-1),
     dynamic_linker,
     migration_path_for_coreos_toolbox.to_string(),
+    get_option('go_build_flags'),
   ],
   input: sources,
   install: true,
   install_dir: get_option('bindir'),
   output: 'toolbox',
 )
 
-if shellcheck.found()
-  test('shellcheck go-build-wrapper', shellcheck, args: [go_build_wrapper_file])
-endif
-
 test('go fmt', meson_go_fmt_program, args: [meson.current_source_dir()])
-test('toolbox go unit tests', go, args: ['test', '-v', './...'], workdir: meson.current_source_dir())
+test('toolbox go unit tests',
+  go,
+  args: ['test', '-v', './...'],
+  depends: toolbox,
+  workdir: meson.current_source_dir()
+)

test/binary/README.md

@@ -0,0 +1,23 @@
+# Binary tests
+
+These tests test the Toolbx binary if it is properly set up (e.g., rpath, path
+to dynamic linker)
+
+## Dependencies
+
+- `go`
+
+## How to run the tests
+
+The tests are best run using the build system that takes care of passing proper
+values to them.
+
+In case you want/need to run them manually run this command in this directory:
+
+```shell
+$ go test ./... -args <path-to-toolbx-binary> <path-to-file-with-build-overrides>
+```
+
+The tests read the tested values from a file where the build script wrote the
+values it embeded into the binary. The values are space-separated on a single
+line.