xci: scripts: start-new-vm.sh: Rework fix for parallel pkg mgr instances

The current way of detecting whether multiple package manager processes
are running is not ideal so just wait a random amount of time if we
detect that another instance of our package manager command is running.

Change-Id: Id94e3ed5293bf223f7250f92525a6e02bb1ea842
Signed-off-by: Markos Chandras <mchandras@suse.de>

diff --git a/xci/scripts/vm/start-new-vm.sh b/xci/scripts/vm/start-new-vm.sh
index a694274..e6c122c 100755 (executable)
--- a/xci/scripts/vm/start-new-vm.sh
+++ b/xci/scripts/vm/start-new-vm.sh
@@ -45,22 +45,6 @@ usage() {
        """
 }
 
-wait_for_pkg_mgr() {
-       local pkg_mgr=$1
-       local _retries=30
-       while [[ $_retries -gt 0 ]]; do
-               if pgrep -a $pkg_mgr &> /dev/null; then
-                       echo "There is another $pkg_mgr process running... ($_retries retries left)"
-                       sleep 30
-                       (( _retries = _retries - 1 ))
-               else
-                       return 0
-               fi
-       done
-       echo "$pkg_mgr still running... Maybe stuck?"
-       exit 1
-}
-
 update_clean_vm_files() {
        local opnfv_url="http://artifacts.opnfv.org/releng/xci/images"
        local vm_cache=${XCI_CACHE_DIR}/clean_vm/images
@@ -127,22 +111,33 @@ if ! sudo -n "true"; then
        echo "$(id -nu) ALL=(ALL) NOPASSWD: ALL"
        exit 1
 fi
+
+# Wait 30-120 seconds so we avoid running multiple instances of pkg manager. Of course
+# this will not work as it should if there is an external process running a package
+# manager instance. However, since this script is only being execute on CI nodes which
+# we have complete control it should be mostly fine.
+backoff_time=0
+while [[ ${backoff_time} -le 30 ]]; do
+       backoff_time=$(( $RANDOM % 120 ))
+done
+
 case ${ID,,} in
        *suse)
-               wait_for_pkg_mgr zypper
-               sudo zypper -q -n in virt-manager qemu-kvm qemu-tools libvirt-daemon docker libvirt-client libvirt-daemon-driver-qemu iptables ebtables dnsmasq
+               pkg_mgr_cmd="sudo zypper -q -n install virt-manager qemu-kvm qemu-tools libvirt-daemon docker libvirt-client libvirt-daemon-driver-qemu iptables ebtables dnsmasq"
                ;;
        centos)
-               wait_for_pkg_mgr yum
-               sudo yum install -q -y epel-release
-               sudo yum install -q -y in virt-manager qemu-kvm qemu-kvm-tools qemu-img libvirt-daemon-kvm docker iptables ebtables dnsmasq
+               pkg_mgr_cmd="sudo yum install -q -y epel-release && sudo yum install -q -y in virt-manager qemu-kvm qemu-kvm-tools qemu-img libvirt-daemon-kvm docker iptables ebtables dnsmasq"
                ;;
        ubuntu)
-               wait_for_pkg_mgr apt-get
-               sudo apt-get install -y -q=3 virt-manager qemu-kvm libvirt-bin qemu-utils docker.io docker iptables ebtables dnsmasq
+               pkg_mgr_cmd="sudo apt-get install -y -q=3 virt-manager qemu-kvm libvirt-bin qemu-utils docker.io docker iptables ebtables dnsmasq"
                ;;
 esac
 
+if pgrep -fa "${pkg_mgr_cmd%*install*}" 2>&1; then
+       sleep ${backoff_time}
+fi
+eval ${pkg_mgr_cmd}
+
 echo "Ensuring libvirt and docker services are running..."
 sudo systemctl -q start libvirtd
 sudo systemctl -q start docker