Use a PostgreSQL version agnostic method of determining if the database exists (#77)

Use PG version agnostic method to find DB

Author: lildude

rootfs/etc/s6-overlay/s6-rc.d/teslamate/run

@@ -59,9 +59,9 @@ fi
 
 # Create the PostgreSQL database if it doesn't exist
 if pg_isready -h "$DATABASE_HOST" -p "$DATABASE_PORT" > /dev/null 2>&1; then
-  bashio::log.info "Creating database '$DATABASE_NAME' on $DATABASE_HOST"
+  bashio::log.info "Checking for database '$DATABASE_NAME' on $DATABASE_HOST"
 
-  if [[ -n $(PGPASSWORD="$DATABASE_PASS" psql -h "$DATABASE_HOST" -p "$DATABASE_PORT" -U "$DATABASE_USER" postgres -Atqc "\list \"$DATABASE_NAME\"") ]]; then
+  if [[ -n $(PGPASSWORD="$DATABASE_PASS" psql -h "$DATABASE_HOST" -p "$DATABASE_PORT" -U "$DATABASE_USER" postgres -Atqc "SELECT datname FROM pg_database WHERE datname = '$DATABASE_NAME'") ]]; then
     bashio::log.info "Database $DATABASE_NAME already exists"
   else
     if PGPASSWORD="$DATABASE_PASS" psql -h "$DATABASE_HOST" -p "$DATABASE_PORT" -U "$DATABASE_USER" postgres -qc "CREATE DATABASE \"$DATABASE_NAME\""; then
@@ -76,7 +76,7 @@ else
   exit 1
 fi
 
-if [[ -z $(PGPASSWORD="$DATABASE_PASS" psql -h "$DATABASE_HOST" -p "$DATABASE_PORT" -U "$DATABASE_USER" "$DATABASE_NAME" -Atqc "SELECT 1 FROM settings WHERE base_url LIKE '%api/hassio_ingress%'") ]]; then
+if [[ -z $(PGPASSWORD="$DATABASE_PASS" psql -h "$DATABASE_HOST" -p "$DATABASE_PORT" -U "$DATABASE_USER" "$DATABASE_NAME" -Atqc "SELECT 1 FROM settings WHERE base_url LIKE '%api/hassio_ingress%'" 2&> /dev/null ) ]]; then
   teslamate_ingress=$(bashio::addon.ingress_entry)
   grafana_ingress=$(bashio::addon.ingress_entry $(bashio::supervisor.addons | grep grafana))