[bbb-greenlight] Add simplified entrypoint

[Bartłomiej Piotrowski <bpiotrowski src gnome org>]

commit c9e7f97d3ff5e95c502ff3b89b000d88f37d5e33
Author: Bartłomiej Piotrowski <bpiotrowski gnome org>
Date:   Mon Jun 14 15:44:47 2021 +0200

    Add simplified entrypoint

 Dockerfile |  4 ++++
 entrypoint | 11 +++++++++++
 2 files changed, 15 insertions(+)
---
diff --git a/Dockerfile b/Dockerfile
index b264efa..a03ae5c 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -1,5 +1,9 @@
 FROM bigbluebutton/greenlight:v2
+
 ADD ldap.patch /ldap.patch
 RUN apk add -U patch && \
     patch -p1 -i /ldap.patch && \
     rm -f /ldap.patch
+
+ADD entrypoint /entrypoint
+ENTRYPOINT ["/entrypoint.sh"]
diff --git a/entrypoint b/entrypoint
new file mode 100755
index 0000000..3c24e6f
--- /dev/null
+++ b/entrypoint
@@ -0,0 +1,11 @@
+#!/bin/bash
+
+while ! curl http://$DB_HOST:${DB_PORT:-5432}/ 2>&1 | grep '52'; do
+  echo "Waiting for postgres to start up ..."
+sleep 1
+done
+
+bundle exec rake db:migrate
+bundle exec rake assets:precompile
+
+exec bundle exec puma -C config/puma.rb