This directory contains scripts for migrating an SQLite database to a PostgreSQL database as well as setting up a new database with the server ID.

## Prerequisites

- Postgres installed and running
- Liquibase installed (Automated with [[Postgres + docker compose setup]])
- Execution of Liquibase scripts (Automated with [[Postgres + docker compose setup]])
- SQLite database file(s) to be migrated(for upgrades only)

## Setup

In `/usr/vcs/docker/migration-scripts` modify the `.pgpass` file in with the correct content: `hostname:port:database:username:password`

For example:
```
localhost:5432:postgres:vcs:vcs
```

   >Replace with the actual information of your Postgres database. If your password contains special characters, make sure to escape them with a backslash \\

Make the scripts are executable and set the correct permissions for the `.pgpass` file:
```
chmod +x database_migration.sh
chmod +x disable_constraints.sh
chmod +x create_db_dump.sh
chmod +x transform_db_dump.sh
chmod +x consolidate.sh
chmod +x update_server_id.sh
chmod 600 .pgpass
```

**Existing server upgrade only:**
For single server grab the `vcs.db` file, and rename it `serverID.db`(use the actual server id of the server, in case of `vcs.db-wall` and `vcs.db-shm` rename those with the server id as well)
For multi server gather all the `vcs.db` files and rename as mentioned in the single server step

Move the database file(s) to the scripts directory(`/usr/vcs/docker/migration-scripts`)

## Running the Migration

ServerID - server id for the server
PSQL_PATH - path to Postgres psql
Example: `docker exec -i artsentry-services-postgres-1 psql`

`artsentry-services-postgres-1` - name of the Docker container which can be found by running `docker ps` ([[running services.png]])

#### New Server Install

Run the `update_server_id.sh` script with the `ServerID` and the `PSQL_PATH` parameter:

Example of running the script with Docker instance of Postgres:

```bash
./update_server_id.sh 'server_id' 'docker exec -i artsentry-services-postgres-1 psql'
```

Example of running the script with local instance of Postgres:

```bash
./update_server_id.sh 'server_id' '/opt/homebrew/Cellar/postgresql@16/16.2_1/bin/psql'
```

If you want to redirect the output to a different file, use the following command:

```bash
./update_server_id.sh 'server_id' 'docker exec -i artsentry-services-postgres-1 psql' > migration.log
```

#### Existing Server Upgrade

To run the migration process, execute the `database_migration.sh` script with `PSQL_PATH` parameter:

Example of running the script with Docker instance of PostgreSQL:

```bash
./database_migration.sh 'docker exec -i artsentry-services-postgres-1 psql'
```

Example of running the script with local instance of PostgreSQL:

```bash
./database_migration.sh '/opt/homebrew/Cellar/postgresql@16/16.2_1/bin/psql'
```

If you want to redirect the output to a different file, use the following command:

```bash
./database_migration.sh 'docker exec -i artsentry-services-postgres-1 psql' > migration.log
```

#### Start VCS Server 
After completing the required steps in [[Postgres + docker compose setup]] and executing the script(s) above, start the VCS Server

```bash
systemctl start vcs
```


## Scripts Description(FYI)

- **database_migration.sh**: Main script that orchestrates the migration process
- **disable_constraints.sh**: Disables constraints in the PostgreSQL database to prevent conflicts during data import
- **create_db_dump.sh**: Creates a dump of the SQLite database that can be imported into the PostgreSQL database
- **transform_db_dump.sh**: Transforms the SQLite dump to be compatible with Postgres
- **consolidate.sh**: Consolidates the transformed dump into the PostgreSQL database
- **update_server_id.sh**: Updates the server ID in the Postgres database after the migration or at new setup