move IsInstalled and apt-fast

images/linux/scripts/base/apt.sh

@@ -1,9 +1,18 @@
 #!/bin/bash
 
 export DEBIAN_FRONTEND=noninteractive
-apt-get -yqq update
-apt-get -yqq dist-upgrade
+apt-get -yq update
+apt-get -yq dist-upgrade
 systemctl disable apt-daily.service
 systemctl disable apt-daily.timer
 systemctl disable apt-daily-upgrade.timer
 systemctl disable apt-daily-upgrade.service
+
+# Configure apt to always assume Y
+echo "APT::Get::Assume-Yes \"true\";" > /etc/apt/apt.conf.d/90assumeyes
+
+# Use apt-fast for parallel downloads
+apt-get install aria2
+add-apt-repository -y ppa:apt-fast/stable
+apt-get update
+apt-get -y install apt-fast

images/linux/scripts/helpers/install.sh

@@ -33,4 +33,13 @@ download_with_retries() {
 
     echo "Could not download $URL"
     return 1
+}
+
+## Use dpkg to figure out if a package has already been installed
+## Example use:
+## if ! IsInstalled packageName; then
+##     echo "packageName is not installed!"
+## fi
+function IsInstalled {
+    dpkg -S $1 &> /dev/null
 }

images/linux/scripts/installers/build-essential.sh

@@ -6,6 +6,7 @@
 
 # Source the helpers for use with the script
 source $HELPER_SCRIPTS/document.sh
+source $HELPER_SCRIPTS/install.sh
 
 PACKAGE=build-essential
 

images/linux/scripts/installers/docker-moby.sh

@@ -5,6 +5,7 @@
 ################################################################################
 
 source $HELPER_SCRIPTS/document.sh
+source $HELPER_SCRIPTS/install.sh
 source $HELPER_SCRIPTS/os.sh
 
 docker_package=moby

images/linux/scripts/installers/dotnetcore-sdk.sh

@@ -3,8 +3,10 @@
 ##  File:  dotnetcore-sdk.sh
 ##  Desc:  Installs .NET Core SDK
 ################################################################################
+
 source $HELPER_SCRIPTS/etc-environment.sh
 source $HELPER_SCRIPTS/document.sh
+source $HELPER_SCRIPTS/install.sh
 source $HELPER_SCRIPTS/os.sh
 
 # Ubuntu 20 doesn't support EOL versions

images/linux/scripts/installers/hhvm.sh

@@ -6,6 +6,7 @@
 
 # Source the helpers for use with the script
 source $HELPER_SCRIPTS/document.sh
+source $HELPER_SCRIPTS/install.sh
 
 hhvm_package=hhvm