puppet: Install wal-g, not wal-e.

docs/production/export-and-import.md

@@ -160,7 +160,7 @@ data includes:
 
 * The postgres database.  You can back it up like any postgres
 database. We have some example tooling for doing that incrementally
-into S3 using [wal-e](https://github.com/wal-e/wal-e) in
+into S3 using [wal-g](https://github.com/wal-g/wal-g) in
 `puppet/zulip_ops/manifests/postgres_common.pp`.
 In short, this requires:
   - Zulip 1.4 or newer release.
@@ -207,7 +207,7 @@ To restore from a manual backup, the process is basically the reverse of the abo
 * If you ran `initialize-database` anyway above, you'll want to run
   `scripts/setup/postgres-init-db` to drop the initial database first.
 
-* Restore your database from the backup using `wal-e`.
+* Restore your database from the backup.
 
 * Reconfigure rabbitmq to use the password from `secrets.conf`
   by running, as root, `scripts/setup/configure-rabbitmq`.

puppet/zulip_ops/manifests/postgres_common.pp

@@ -1,23 +1,16 @@
 class zulip_ops::postgres_common {
   include zulip::postgres_common
 
-  $internal_postgres_packages = [# dependencies for our wal-e backup system
-    'lzop',
-    'pv',
-    'python3-pip',
-    'python-pip',
-    'python3-gevent',
-    'python-gevent',
-  ]
-  package { $internal_postgres_packages: ensure => 'installed' }
+  $wal_g_version = '0.2.15'
+  $wal_g_hash = 'ea33c2341d7bfb203c6948590c29834c013ab06a28c7a2b236a73d906f785c84'
+  exec {'install-wal-g':
+    command => "${::zulip_scripts_path}/setup/install-wal-g ${wal_g_version} ${wal_g_hash}",
+    creates => "/usr/local/bin/wal-g-${wal_g_version}",
+  }
 
-  exec {'pip_wal-e':
-    # On trusty, there is no python3-boto or python3-gevent package,
-    # so we keep our `wal-e` explicitly on Python 2 for now.
-    command => '/usr/bin/pip2 install git+git://github.com/zbenjamin/wal-e.git#egg=wal-e',
-    creates => '/usr/local/bin/wal-e',
-    require => Package['python-pip', 'python-boto', 'python-gevent',
-                        'lzop', 'pv'],
+  file { '/usr/local/bin/wal-g':
+    ensure => 'link',
+    target => "/usr/local/bin/wal-g-${wal_g_version}",
   }
 
   cron { 'pg_backup_and_purge':

scripts/setup/install-wal-g.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+
+set -e
+set -x
+
+VERSION="$1"
+HASH="$2"
+
+cd /tmp
+wget -qO "wal-g-$VERSION.tar.gz" \
+     "https://github.com/wal-g/wal-g/releases/download/v$VERSION/wal-g.linux-amd64.tar.gz"
+
+# Check not against the arbitrary provided sha256 on Github, but
+# against the (same) sha256 that we hardcode as "known good".
+echo "$HASH  wal-g-$VERSION.tar.gz" > "wal-g-$VERSION.tar.gz.sha256"
+sha256sum -c "wal-g-$VERSION.tar.gz.sha256"
+
+tar xzf "wal-g-$VERSION.tar.gz"
+mv wal-g "/usr/local/bin/wal-g-$VERSION"
+rm "wal-g-$VERSION.tar.gz" "wal-g-$VERSION.tar.gz.sha256"