automation: support and use Debian Buster by default

While Debian Buster (Debian 10) was released in July, the
AWS AMIs were not published until mid September.

This commit teaches the automation system to create AMIs for
Debian Buster. Since Debian Buster is the new stable Debian
release, we make it the default distribution for automation.

Differential Revision: https://phab.mercurial-scm.org/D6917

contrib/automation/hgautomation/aws.py

@@ -54,6 +54,7 b' INSTANCE_TYPES_WITH_STORAGE = {'
 
 AMAZON_ACCOUNT_ID = '801119661308'
 DEBIAN_ACCOUNT_ID = '379101102735'
+DEBIAN_ACCOUNT_ID_2 = '136693071363'
 UBUNTU_ACCOUNT_ID = '099720109477'
 
 
@@ -807,7 +808,7 b' def create_ami_from_instance(ec2client, '
     return image
 
 
-def ensure_linux_dev_ami(c: AWSConnection, distro='debian9', prefix='hg-'):
+def ensure_linux_dev_ami(c: AWSConnection, distro='debian10', prefix='hg-'):
     """Ensures a Linux development AMI is available and up-to-date.
 
     Returns an ``ec2.Image`` of either an existing AMI or a newly-built one.
@@ -824,6 +825,13 b' def ensure_linux_dev_ami(c: AWSConnectio'
             'debian-stretch-hvm-x86_64-gp2-2019-09-08-17994',
         )
         ssh_username = 'admin'
+    elif distro == 'debian10':
+        image = find_image(
+            ec2resource,
+            DEBIAN_ACCOUNT_ID_2,
+            'debian-10-amd64-20190909-10',
+        )
+        ssh_username = 'admin'
     elif distro == 'ubuntu18.04':
         image = find_image(
             ec2resource,

contrib/automation/hgautomation/cli.py

@@ -352,7 +352,7 b' def get_parser():'
         '--distro',
         help='Linux distribution to run tests on',
         choices=linux.DISTROS,
-        default='debian9',
+        default='debian10',
     )
     sp.add_argument(
         '--filesystem',

contrib/automation/hgautomation/linux.py

@@ -21,6 +21,7 b' from .ssh import ('
 # Linux distributions that are supported.
 DISTROS = {
     'debian9',
+    'debian10',
     'ubuntu18.04',
     'ubuntu19.04',
 }
@@ -190,14 +191,18 b' if [ "$LSB_RELEASE" = "stretch" ]; then'
 cat << EOF | sudo tee -a /etc/apt/sources.list
 # Need backports for clang-format-6.0
 deb http://deb.debian.org/debian stretch-backports main
+EOF
+fi
 
+if [ "$LSB_RELEASE" = "stretch" -o "$LSB_RELEASE" = "buster" ]; then
+cat << EOF | sudo tee -a /etc/apt/sources.list
 # Sources are useful if we want to compile things locally.
-deb-src http://deb.debian.org/debian stretch main
-deb-src http://security.debian.org/debian-security stretch/updates main
-deb-src http://deb.debian.org/debian stretch-updates main
-deb-src http://deb.debian.org/debian stretch-backports main
+deb-src http://deb.debian.org/debian $LSB_RELEASE main
+deb-src http://security.debian.org/debian-security $LSB_RELEASE/updates main
+deb-src http://deb.debian.org/debian $LSB_RELEASE-updates main
+deb-src http://deb.debian.org/debian $LSB_RELEASE-backports main
 
-deb [arch=amd64] https://download.docker.com/linux/debian stretch stable
+deb [arch=amd64] https://download.docker.com/linux/debian $LSB_RELEASE stable
 EOF
 
 elif [ "$DISTRO" = "Ubuntu" ]; then
@@ -279,8 +284,8 b' elif [ "$DISTRO" = "Ubuntu" ]; then'
     PACKAGES="$PACKAGES linux-tools-common"
 fi
 
-# Ubuntu 19.04 removes monotone.
-if [ "$LSB_RELEASE" != "disco" ]; then
+# Monotone only available in older releases.
+if [ "$LSB_RELEASE" = "stretch" -o "$LSB_RELEASE" = "xenial" ]; then
     PACKAGES="$PACKAGES monotone"
 fi