apt lock hygiene

- only invoke an apt command if nothing else is holding a lock
- only return after an apt command after locks are verified released

parts/k8s/kubernetesprovisionsource.sh

@@ -120,10 +120,17 @@ wait_for_file() {
         fi
     done
 }
+wait_for_apt_locks() {
+    while fuser /var/lib/dpkg/lock /var/lib/apt/lists/lock /var/cache/apt/archives/lock >/dev/null 2>&1; do
+        echo 'Waiting for release of apt locks'
+        sleep 3
+    done
+}
 apt_get_update() {
     retries=10
     apt_update_output=/tmp/apt-get-update.out
     for i in $(seq 1 $retries); do
+        wait_for_apt_locks
         timeout 30 dpkg --configure -a
         timeout 30 apt-get -f -y install
         timeout 120 apt-get update 2>&1 | tee $apt_update_output | grep -E "^([WE]:.*)|([eE]rr.*)$"
@@ -135,10 +142,12 @@ apt_get_update() {
         fi
     done
     echo Executed apt-get update $i times
+    wait_for_apt_locks
 }
 apt_get_install() {
     retries=$1; wait_sleep=$2; timeout=$3; shift && shift && shift
     for i in $(seq 1 $retries); do
+        wait_for_apt_locks
         timeout 30 dpkg --configure -a
         timeout $timeout apt-get install --no-install-recommends -y ${@}
         [ $? -eq 0  ] && break || \
@@ -150,6 +159,7 @@ apt_get_install() {
         fi
     done
     echo Executed apt-get install --no-install-recommends -y \"$@\" $i times;
+    wait_for_apt_locks
 }
 systemctl_restart() {
     retries=$1; wait_sleep=$2; timeout=$3 svcname=$4
@@ -163,4 +173,4 @@ systemctl_restart() {
             sleep $wait_sleep
         fi
     done
-}
+}

parts/k8s/setup-custom-search-domains.sh

@@ -4,5 +4,7 @@ source /opt/azure/containers/provision_source.sh
 
 sudo echo "  dns-search <searchDomainName>" >> /etc/network/interfaces.d/50-cloud-init.cfg
 systemctl_restart 20 5 10 restart networking
+wait_for_apt_locks
 retrycmd_if_failure 10 5 120 apt-get -y install realmd sssd sssd-tools samba-common samba samba-common python2.7 samba-libs packagekit
+wait_for_apt_locks
 echo "<searchDomainRealmPassword>" | realm join -U <searchDomainRealmUser>@`echo "<searchDomainName>" | tr /a-z/ /A-Z/` `echo "<searchDomainName>" | tr /a-z/ /A-Z/`