Ensure python2 is installed before hook execution

Change-Id: I724eaea5f09191b548e5497f9bb2c777f882d290
Closes-Bug: 1606906

hooks/hooks.py

@@ -103,7 +103,7 @@ SUPPORTED_TRANSPORTS = ['udp', 'udpu', 'multicast', 'unicast']
 DEPRECATED_TRANSPORT_VALUES = {"multicast": "udp", "unicast": "udpu"}
 
 
-@hooks.hook()
+@hooks.hook('install.real')
 def install():
     ubuntu_release = lsb_release()['DISTRIB_CODENAME'].lower()
     if CompareHostReleases(ubuntu_release) >= 'zesty':

hooks/install

@@ -1 +0,0 @@
-hooks.py

hooks/install

@@ -0,0 +1,20 @@
+#!/bin/bash
+# Wrapper to deal with newer Ubuntu versions that don't have py2 installed
+# by default.
+
+declare -a DEPS=('apt' 'netaddr' 'netifaces' 'pip' 'yaml' 'dnspython')
+
+check_and_install() {
+    pkg="${1}-${2}"
+    if ! dpkg -s ${pkg} 2>&1 > /dev/null; then
+        apt-get -y install ${pkg}
+    fi
+}
+
+PYTHON="python"
+
+for dep in ${DEPS[@]}; do
+    check_and_install ${PYTHON} ${dep}
+done
+
+exec ./hooks/install.real

hooks/install.real

@@ -0,0 +1 @@
+hooks.py