fix: Migration scripts and guide (#229)

* feat: Add functionality for OUTPUT_PREFIX

* chore: Introduce output name

* chore: Make migration_sql_commands clear

* fix: Destination db version to 16

* fix: postgres-perms script

* chore: Add sanity check to postgres-perms-update.sh

* docs: Mention warning

* chore: remove name string

docs/pg-migration-guide/README.md

@@ -77,7 +77,9 @@ $ tofu apply
 Before proceeding with the DMS creation we will expose the required things by gcloud using the `output` block, add these output blocks to your main tofu file.
 ```sh
 # run the create-dms.sh script located in modules/postgresql/gcp/bin
-$ ./create-dms.sh <main.tf directory> <gcp-project-name> <gcp-region> <dms-migration-job-name>
+# <output-prefix> to be used for output automation 
+# this is the module name of the current project we are performing migration
+$ ./create-dms.sh <main.tf directory> <gcp-project-name> <gcp-region> <dms-migration-job-name> <output-prefix>
 Enter the region: us-east1
 Enter the job name: test-migration
 Creating migration job 'test-migration' in region 'us-east1'...
@@ -134,9 +136,14 @@ $ gcloud database-migration migration-jobs start "test-migration" --region="us-e
 ```sh
 $ gcloud database-migration migration-jobs start "test-migration" --region="us-east1"
 
-# Use the describe command to check the status of the migration-job
+# Use the describe command to check the status of the migration-job !IMPORTANT
 $ gcloud database-migration migration-jobs describe "test-job" --region=us-east1
 
+
+## NOTE:
+
+BEFORE PROMOTING VERIFY THAT THE DMS HAS BEEN SUCCESSFUL BY RUNNING THE `describe` command from earlier.
+
 ```
 # Step 3: Pre-promotion
 
@@ -148,11 +155,13 @@ $ gcloud database-migration migration-jobs describe "test-job" --region=us-east1
 ### Step 3.5: Handing the non-migrated settings and syncing state via `tofu`
 
 #### Step 3.5.1
-Log in to the `destination instance` as the `postgres` user and change the name of the `cloudsqlexternalsync` user to the `<admin-user>`.
-The value of `<admin-user>` and `destination-connection-string` can be found by running
+- Log in to the `destination instance` as the `postgres` user.
+- Change the name of the `cloudsqlexternalsync` user to the `<admin-user>`.
+- The commands to do this can be found by running the following command:
 
 ```sh
-$ tf output -json migration_sql_command | jq -r '.sql_command' | bash
+# get the <admin-user> value here
+$ tf output -json migration_sql_command 
 ```
 
 #### Step 3.5.2
@@ -178,7 +187,7 @@ module "postgresql" {
   #source = "git::https://github.com/GaloyMoney/galoy-infra.git//modules/postgresql/gcp?ref=689daa7"
   source = "../../../modules/postgresql/gcp"
 
-  instance_name          = "rishi-pg"
+  instance_name          = "test-pg"
   vpc_name               = "${var.name_prefix}-vpc"
   gcp_project            = var.gcp_project
   destroyable            = var.destroyable_postgres
@@ -238,7 +247,7 @@ module "postgresql" {
   #source = "git::https://github.com/GaloyMoney/galoy-infra.git//modules/postgresql/gcp?ref=689daa7"
   source = "../../../modules/postgresql/gcp"
 
-  instance_name          = "rishi-pg"
+  instance_name          = "test-pg"
   vpc_name               = "${var.name_prefix}-vpc"
   gcp_project            = var.gcp_project
   destroyable            = var.destroyable_postgres

modules/postgresql/gcp/bin/create-dms.sh

@@ -9,6 +9,9 @@ PROJECT=${2}
 REGION=${3}
 # the migration job name
 JOB_NAME=${4}
+# tofu output prefix to be used for output automation 
+# this is the module name of the current project we are performing migration
+OUTPUT_PREFIX=${5}
 
 TYPE="CONTINUOUS"
 
@@ -43,9 +46,9 @@ else
   cmd="terraform"
 fi
 # Get Terraform outputs
-SOURCE_ID=$($cmd output -raw source_connection_profile_id)
-DEST_ID=$($cmd output -raw destination_connection_profile_id)
-VPC=$($cmd output -raw vpc)
+SOURCE_ID=$($cmd output -raw "${OUTPUT_PREFIX}source_connection_profile_id")
+DEST_ID=$($cmd output -raw "${OUTPUT_PREFIX}destination_connection_profile_id")
+VPC=$($cmd output -raw "${OUTPUT_PREFIX}vpc")
 
 # Construct and run the gcloud command to create the migration job
 echo "Creating migration job '$JOB_NAME' in region '$REGION'..."

modules/postgresql/gcp/bin/postgres-perms-update.sh

@@ -1,22 +1,63 @@
 #!/usr/bin/env bash
 set -e
 
-dir=${1}
-DB_NAME=${2}
+# Function to validate input parameters
+validate_inputs() {
+    if [ -z "$1" ] || [ -z "$2" ]; then
+        echo "Usage: $0 <directory> <database_name>"
+        echo "Error: Both directory and database name are required"
+        exit 1
+    fi
+
+    if [ ! -d "$1" ]; then
+        echo "Error: Directory '$1' does not exist"
+        exit 1
+    fi
+
+    if [ ! -f "$1/pg_connection.txt" ]; then
+        echo "Error: pg_connection.txt not found in $1"
+        exit 1
+    fi
+}
 
-pushd ${dir}
+# Function to test database connection
+test_connection() {
+    local connection=$1
+    local db_name=$2
+
+    if ! psql "$connection/$db_name" -c '\q' >/dev/null 2>&1; then
+        echo "Error: Could not connect to database $db_name"
+        exit 1
+    fi
+}
+
+validate_inputs "$1" "$2"
+
+dir=$1
+DB_NAME=$2
+pushd "${dir}" || exit 1
 
 NEW_OWNER=${DB_NAME}-user
 # READ PG_CON from a file
 PG_CON=$(cat pg_connection.txt)
 
-PSQL_CMD="psql $PG_CON -At -c"
+# Test connections before proceeding
+test_connection "$PG_CON" "postgres"
+test_connection "$PG_CON" "$DB_NAME"
 
-$PSQL_CMD "ALTER DATABASE postgres OWNER TO cloudsqlsuperuser;"
-$PSQL_CMD "ALTER SCHEMA public OWNER TO cloudsqlsuperuser;"
+# Command for database owner change needs to connect to postgres database
+PSQL_CMD_POSTGRES="psql $PG_CON/postgres -At -c"
+# Command for all other operations needs to connect to target database
+PSQL_CMD="psql $PG_CON/$DB_NAME -At -c"
 
+echo "Starting ownership transfer process..."
+
+# Perform ownership changes
+$PSQL_CMD_POSTGRES "ALTER DATABASE postgres OWNER TO cloudsqlsuperuser;"
+$PSQL_CMD "ALTER SCHEMA public OWNER TO cloudsqlsuperuser;"
 $PSQL_CMD "GRANT \"$NEW_OWNER\" TO \"postgres\";"
-# Get list of all tables in the database
+
+# Get and process tables
 tables=$($PSQL_CMD "SELECT tablename FROM pg_tables WHERE schemaname = 'public';")
 
 # Loop through each table and change the owner
@@ -32,6 +73,7 @@ for sequence in $sequences; do
     $PSQL_CMD "ALTER SEQUENCE public.\"$sequence\" OWNER TO \"$NEW_OWNER\";"
 done
 
-echo "Ownership of all tables in $DB_NAME has been granted to $NEW_OWNER."
+echo "Ownership transfer process completed for $DB_NAME"
+echo "Please review any warnings above"
 
-popd
+popd || exit 1

modules/postgresql/gcp/outputs.tf

@@ -61,6 +61,8 @@ output "source_instance" {
 }
 output "migration_sql_command" {
   value = local.prep_upgrade_as_source_db ? {
-    sql_command = "psql postgres://postgres:${module.migration[0].postgres_user_password}@${module.migration[0].destination_instance_private_ip_address}:5432/postgres -c \"ALTER ROLE cloudsqlexternalsync RENAME TO \\\"${google_sql_user.admin.name}\\\"; ALTER ROLE \\\"${google_sql_user.admin.name}\\\" PASSWORD '${random_password.admin.result}';\""
+    destination_connection_string = "psql postgres://postgres:${module.migration[0].postgres_user_password}@${module.migration[0].destination_instance_private_ip_address}:5432/postgres"
+    alter_admin_name              = "ALTER ROLE cloudsqlexternalsync RENAME TO ${google_sql_user.admin.name}"
+    alter_admin_password          = "ALTER ROLE ${google_sql_user.admin.name} PASSWORD ${random_password.admin.result}"
   } : {}
 }

modules/postgresql/gcp/variables.tf

@@ -26,7 +26,7 @@ variable "database_version" {
   default = "POSTGRES_14"
 }
 variable "destination_database_version" {
-  default = "POSTGRES_15"
+  default = "POSTGRES_16"
 }
 variable "big_query_viewers" {
   default = []