Merge lp:~salgado/linaro-image-tools/port-ensure_command into lp:linaro-image-tools/11.11

[Guilherme Salgado]

Port ensure_command to python.

I've used os.system() to call 'which' and 'apt-get', but I'm happy to change that to a subprocess.Popen() if anybody feels it's worth doing so.

[Martin Ohlsson (martin-ohlson)]

Hi Guilherme,

I think code looks fine. I had to do some reading on context managers to be able to fully understand it ;)

/Martin

review: Approve

=== modified file 'linaro-media-create'
--- linaro-media-create	2010-11-23 12:02:34 +0000
+++ linaro-media-create	2010-11-23 12:02:34 +0000
@@ -70,13 +70,8 @@
 # off of a l-m-c working tree.
 export PYTHONPATH="$script_dir"
 
-ensure_command() {
-  # ensure_command foo foo-package
-  which "$1" 2>/dev/null 1>/dev/null || ( echo "Installing required command $1 from package $2" && sudo apt-get install "$2" )
-}
-
-ensure_command sfdisk util-linux
-ensure_command fdisk util-linux
+python -m media_create.ensure_command sfdisk util-linux
+python -m media_create.ensure_command fdisk util-linux
 
 usage() {
   echo "usage: $(basename $0) --mmc /dev/sdd"
@@ -281,18 +276,18 @@
 
 DEPLOY_STEPS="$PARTITION_STEP prepare_partitions $BOOTFS_STEP $ROOTFS_STEP"
 
-ensure_command mkimage uboot-mkimage
-ensure_command uuidgen uuid-runtime
-ensure_command parted parted
-ensure_command wget wget
-ensure_command md5sum coreutils
-ensure_command realpath realpath
+python -m media_create.ensure_command mkimage uboot-mkimage
+python -m media_create.ensure_command uuidgen uuid-runtime
+python -m media_create.ensure_command parted parted
+python -m media_create.ensure_command wget wget
+python -m media_create.ensure_command md5sum coreutils
+python -m media_create.ensure_command realpath realpath
 case "$RFS" in
   ext2|ext3|ext4)
-    ensure_command "mkfs.$RFS" e2fsprogs
+    python -m media_create.ensure_command "mkfs.$RFS" e2fsprogs
     ;;
   btrfs)
-    ensure_command mkfs.btrfs btrfs-tools
+    python -m media_create.ensure_command mkfs.btrfs btrfs-tools
     ;;
 esac
 
@@ -356,8 +351,8 @@
       arch_is_arm=yes
       ;;
     *)
-      ensure_command qemu-arm-static qemu-arm-static
-      ensure_command qemu-img qemu-kvm
+      python -m media_create.ensure_command qemu-arm-static qemu-arm-static
+      python -m media_create.ensure_command qemu-img qemu-kvm
       sudo cp /usr/bin/qemu-arm-static ${chroot}/usr/bin
       ;;
   esac
 
=== added file 'media_create/ensure_command.py'
--- media_create/ensure_command.py	1970-01-01 00:00:00 +0000
+++ media_create/ensure_command.py	2010-11-23 12:02:34 +0000
@@ -0,0 +1,17 @@
+import os
+import sys
+
+
+def apt_get_install(command, package):
+    print ("Installing required command %s from package %s"
+           % (command, package))
+    os.system('sudo apt-get install %s' % package)
+
+
+def ensure_command(command, package):
+    if os.system('which %s 2>/dev/null 1>/dev/null' % command) != 0:
+        apt_get_install(command, package)
+
+
+if __name__ == '__main__':
+    ensure_command(sys.argv[1], sys.argv[2])
 
=== modified file 'media_create/tests/test_media_create.py'
--- media_create/tests/test_media_create.py	2010-11-23 12:02:34 +0000
+++ media_create/tests/test_media_create.py	2010-11-23 12:02:34 +0000
@@ -1,9 +1,35 @@
+from contextlib import contextmanager
 import subprocess
 import sys
 
 from testtools import TestCase
 
 from media_create.boot_cmd import create_boot_cmd
+from media_create import ensure_command
+
+
+class TestEnsureCommand(TestCase):
+
+    apt_get_called = False
+
+    def test_command_already_present(self):
+        with self.mock_apt_get_install():
+            ensure_command.ensure_command('apt-get', 'apt')
+        self.assertFalse(self.apt_get_called)
+
+    def test_command_not_present(self):
+        with self.mock_apt_get_install():
+            ensure_command.ensure_command('apt-get-two-o', 'apt-2')
+        self.assertTrue(self.apt_get_called)
+
+    @contextmanager
+    def mock_apt_get_install(self):
+        def mock_apt_get_install(cmd, pkg):
+            self.apt_get_called = True
+        orig_func = ensure_command.apt_get_install
+        ensure_command.apt_get_install = mock_apt_get_install
+        yield
+        ensure_command.apt_get_install = orig_func
 
 
 class TestCreateBootCMD(TestCase):