Add script+Dockerfile to test restoring from fresh backup every 24 hours

README.md

@@ -18,10 +18,14 @@
 
 Reference: https://www.postgresql.org/docs/current/continuous-archiving.html
 
-1. Exec into a new container that is running the postgres image
-2. Make sure that `$PGDATA` is empty
-3. Run this script to download the backup and untar it into the $PGDATA directory
-```
-gsutil cp gs://<bucket>/<filename>.tar.zst - | tar -I zstd -xvf - -C $PGDATA
-```
-4. `pg_ctl -D $PGDATA reload`
+1. Create a caprover app.
+2. Check "Do not expose as web-app"
+3. Specify the following environment variables in the App Configs tab
+    - `BUCKET_PATH` - The `gs://<bucket>/<filename>.tar.zst` path to the GCS bucket where the db backup should be stored
+    - `GOOGLE_APPLICATION_CREDENTIALS_JSON` - A JSON service account key, that has permission to create/replace objects in above bucket.
+    - `PGHOST`, `PGPORT`, `PGUSER`, `PGPASSWORD` - Should point to your db
+4. Add this github repo in the deployment tab, set captain definition file path to `restore.captain-definition`, and press force deploy.
+
+Ideally, keep a Caprover app configured with the above settings and instance count = 0. When you need to restore,
+set the instance count to 1, and it will automatically restore from the latest backup. Scale down the instance
+count to 0 when done.

restore.Dockerfile

@@ -0,0 +1,24 @@
+ARG POSTGRES_VERSION=15.2
+
+FROM postgres:${POSTGRES_VERSION}
+
+RUN apt-get update && apt-get install -y curl python3
+
+WORKDIR /tmp
+
+COPY ./restore.sh ./restore.sh
+COPY ./run-restore.sh ./run-restore.sh
+
+RUN mkdir -p $PGDATA
+RUN chown -R postgres:postgres $PGDATA
+RUN chmod 0700 $PGDATA
+
+USER postgres
+
+# install gcloud sdk
+#
+RUN curl -s https://dl.google.com/dl/cloudsdk/release/google-cloud-sdk.tar.gz \
+    | tar xz && ./google-cloud-sdk/install.sh -q --usage-reporting=false
+ENV PATH=$PATH:google-cloud-sdk/bin/
+
+CMD ["./run-restore.sh"]

restore.captain-definition

@@ -0,0 +1,4 @@
+{
+    "schemaVersion": 2,
+    "dockerfilePath": "./restore.Dockerfile"
+}

restore.sh

@@ -0,0 +1,16 @@
+pg_isready && pg_ctl -D $PGDATA stop && echo "Stopped running database..."
+
+echo "Deleting existing DB and restoring from $BUCKET_PATH"
+rm -rf $PGDATA/*
+gsutil cp $BUCKET_PATH - | tar -I zstd -xf - -C $PGDATA
+
+chmod 0700 $PGDATA
+
+pg_ctl -D $PGDATA start
+
+if pg_isready -h localhost -p 5432;
+then
+  echo "Database is ready"
+else
+  echo "Database is not ready"
+fi

run-restore.sh

@@ -0,0 +1,15 @@
+# avoid logging secrets!
+set -e
+
+echo '+ echo "$GOOGLE_APPLICATION_CREDENTIALS_JSON" > serviceAccountKey.json'
+echo "$GOOGLE_APPLICATION_CREDENTIALS_JSON" > serviceAccountKey.json
+
+# safe to turn on logging now
+set -ex
+
+gcloud auth activate-service-account --key-file serviceAccountKey.json
+
+while true; do
+  sh restore.sh
+  sleep "${SLEEP:-24h}"
+done