hooks: Add a hook to send a Zulip before/after the deploy.

puppet/zulip/files/hooks/common/zulip_notify.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+set -e
+set -u
+
+if ! zulip_api_key=$(crudini --get /etc/zulip/zulip-secrets.conf secrets zulip_release_api_key); then
+    echo "zulip_notify: No zulip_release_api_key set!  Set zulip_release_api_key in /etc/zulip/zulip-secrets.conf"
+    exit 0
+fi
+
+if ! zulip_notify_bot_email=$(crudini --get /etc/zulip/zulip.conf zulip_notify bot_email); then
+    echo "zulip_notify: No zulip_notify.bot_email set in /etc/zulip/zulip.conf"
+    exit 0
+fi
+
+if ! zulip_notify_server=$(crudini --get /etc/zulip/zulip.conf zulip_notify server); then
+    echo "zulip_notify: No zulip_notify.server set in /etc/zulip/zulip.conf"
+    exit 0
+fi
+
+if ! zulip_notify_stream=$(crudini --get /etc/zulip/zulip.conf zulip_notify stream); then
+    echo "zulip_notify: No zulip_notify.stream set in /etc/zulip/zulip.conf"
+    exit 0
+fi
+
+from=${ZULIP_OLD_MERGE_BASE_COMMIT:-$ZULIP_OLD_VERSION}
+to=${ZULIP_NEW_MERGE_BASE_COMMIT:-$ZULIP_NEW_VERSION}
+deploy_environment=$(crudini --get /etc/zulip/zulip.conf machine deploy_type || echo "development")
+
+echo "zulip_notify: Sending notify of $from .. $to for $deploy_environment to $zulip_notify_server"
+
+zulip_send() {
+    ./zulip-py3-venv/bin/zulip-send \
+        --site "$zulip_notify_server" \
+        --user "$zulip_notify_bot_email" \
+        --api-key "$zulip_api_key" \
+        --stream "$zulip_notify_stream" \
+        --subject "$deploy_environment deploy" \
+        --message "$1"
+}

puppet/zulip/files/hooks/post-deploy.d/zulip_notify.hook

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+set -e
+set -u
+
+source "$(dirname "$0")/../common/zulip_notify.sh"
+zulip_send "Finished deploying from $from to $to on $(hostname)"

puppet/zulip/files/hooks/pre-deploy.d/zulip_notify.hook

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+
+set -e
+set -u
+
+source "$(dirname "$0")/../common/zulip_notify.sh"
+zulip_send "Starting deploy from $from to $to on $(hostname)"

puppet/zulip/manifests/hooks/zulip_notify.pp

@@ -0,0 +1,11 @@
+# @summary Install hook that notifies when a deploy starts/stops
+#
+class zulip::hooks::zulip_notify {
+  include zulip::hooks::base
+
+  zulip::hooks::file { [
+    'common/zulip_notify.sh',
+    'pre-deploy.d/zulip_notify.hook',
+    'post-deploy.d/zulip_notify.hook',
+  ]: }
+}

puppet/zulip_ops/manifests/profile/prod_app_frontend.pp

@@ -1,6 +1,7 @@
 class zulip_ops::profile::prod_app_frontend {
   include zulip_ops::profile::base
   include zulip_ops::app_frontend
+  include zulip::hooks::zulip_notify
 
   file { '/etc/nginx/sites-available/zulip':
     ensure  => file,