From 22974025e145e30e17e9412dc57dae61a9fdfad8 Mon Sep 17 00:00:00 2001
From: Michele Sacchetti <michele.sacchetti@aroundthecode.org>
Date: Wed, 6 Apr 2022 09:49:18 +0200
Subject: [PATCH] GCP wrapper (#83)

* GCP wrapper

Add a GCP wrapper to work on Google SQL instances

* PR fixes

mod doc to readme and query to const
---
 Makefile                 |  4 ++
 README.md                | 11 ++++++
 pkg/postgres/database.go |  3 ++
 pkg/postgres/gcp.go      | 85 ++++++++++++++++++++++++++++++++++++++++
 pkg/postgres/postgres.go |  6 +++
 5 files changed, 109 insertions(+)
 create mode 100644 pkg/postgres/gcp.go

diff --git a/Makefile b/Makefile
index 899c9744..fffe9451 100644
--- a/Makefile
+++ b/Makefile
@@ -11,3 +11,7 @@ unit-test:
 	go tool cover -func coverage.out
 unit-test-coverage: unit-test
 	go tool cover -html coverage.out
+linux-build:
+	@GOBIN=/work/bin GO111MODULE=on GOOS=linux GOARC=x86_64 go build --mod=vendor  -o operator github.com/movetokube/postgres-operator/cmd/manager
+docker-build:
+	docker run -ti -v $(PWD):/work -w /work golang:1.13.15-stretch make linux-build
diff --git a/README.md b/README.md
index 11d1b1d3..f45a1fd6 100644
--- a/README.md
+++ b/README.md
@@ -23,6 +23,17 @@ In order for this operator to work correctly with Azure managed PostgreSQL datab
 * `POSTGRES_CLOUD_PROVIDER` set to `Azure`
 * `POSTGRES_DEFAULT_DATABASE` set to your default database, i.e. `postgres`
 
+### GCP
+
+In order for this operator to work correctly with GCP, you need to set `POSTGRES_CLOUD_PROVIDER` to `GCP` 
+
+To have operator work with GCP properly you have to:
+* use postgresql connection in secret
+* manually create a Master role e.g. "devops-operators"
+* use such role in database CR e.g. spec.masterRole: devops-operator
+
+DropRole method will check for db owner and will skip master role dropping
+
 ## Installation
 
 This operator requires a Kubernetes Secret to be created in the same namespace as operator itself.
diff --git a/pkg/postgres/database.go b/pkg/postgres/database.go
index 1a125001..b499685a 100644
--- a/pkg/postgres/database.go
+++ b/pkg/postgres/database.go
@@ -16,6 +16,9 @@ const (
 	GRANT_USAGE_SCHEMA   = `GRANT USAGE ON SCHEMA "%s" TO "%s"`
 	GRANT_ALL_TABLES     = `GRANT %s ON ALL TABLES IN SCHEMA "%s" TO "%s"`
 	DEFAULT_PRIVS_SCHEMA = `ALTER DEFAULT PRIVILEGES FOR ROLE "%s" IN SCHEMA "%s" GRANT %s ON TABLES TO "%s"`
+	REVOKE_CONNECT		 = `REVOKE CONNECT ON DATABASE "%s" FROM public`
+	TERMINATE_BACKEND	 = `SELECT pg_terminate_backend(pg_stat_activity.pid) FROM pg_stat_activity	WHERE pg_stat_activity.datname = "%s" AND pid <> pg_backend_pid()`
+	GET_DB_OWNER	 	 = `SELECT pg_catalog.pg_get_userbyid(d.datdba) FROM pg_catalog.pg_database d WHERE d.datname = "%s"`
 	GRANT_CREATE_SCHEMA  = `GRANT CREATE ON DATABASE "%s" TO "%s"`
 )
 
diff --git a/pkg/postgres/gcp.go b/pkg/postgres/gcp.go
new file mode 100644
index 00000000..9ebb1ec6
--- /dev/null
+++ b/pkg/postgres/gcp.go
@@ -0,0 +1,85 @@
+package postgres
+
+import (
+	"fmt"
+
+	"github.com/go-logr/logr"
+	"github.com/lib/pq"
+)
+
+type gcppg struct {
+	pg
+}
+
+func newGCPPG(postgres *pg) PG {
+	return &gcppg{
+		*postgres,
+	}
+}
+
+func (c *gcppg) DropDatabase(database string, logger logr.Logger) error {
+
+	_, err := c.db.Exec(fmt.Sprintf(REVOKE_CONNECT, database))
+	// Error code 3D000 is returned if database doesn't exist
+	if err != nil && err.(*pq.Error).Code != "3D000" {
+		return err
+	}
+
+	_, err = c.db.Exec(fmt.Sprintf(TERMINATE_BACKEND, database))
+	// Error code 3D000 is returned if database doesn't exist
+	if err != nil && err.(*pq.Error).Code != "3D000" {
+		return err
+	}
+	_, err = c.db.Exec(fmt.Sprintf(DROP_DATABASE, database))
+	// Error code 3D000 is returned if database doesn't exist
+	if err != nil && err.(*pq.Error).Code != "3D000" {
+		return err
+	}
+
+	logger.Info(fmt.Sprintf("Dropped database %s", database))
+
+	return nil
+}
+
+func (c *gcppg) CreateDB(dbname, role string) error {
+
+	err := c.GrantRole(role, c.user)
+	if err != nil {
+		return err
+	}
+	err = c.pg.CreateDB(dbname, role)
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (c *gcppg) DropRole(role, newOwner, database string, logger logr.Logger) error {
+	
+	tmpDb, err := GetConnection(c.user, c.pass, c.host, database, c.args, logger)
+	q := fmt.Sprintf(GET_DB_OWNER, database)
+	logger.Info("Checking master role: "+ q)
+	rows, err := tmpDb.Query(q)
+	if err != nil {
+		return err
+	}
+	var masterRole string
+	for rows.Next() {
+		rows.Scan(&masterRole)
+	}
+
+	if( role != masterRole){
+		q = fmt.Sprintf(DROP_ROLE, role)
+		logger.Info("GCP Drop Role: "+ q)
+		_, err = tmpDb.Exec(q)
+		// Check if error exists and if different from "ROLE NOT FOUND" => 42704
+		if err != nil && err.(*pq.Error).Code != "42704" {
+			return err
+		}
+
+		defer tmpDb.Close()
+	} else {
+		logger.Info(fmt.Sprintf("GCP refusing DropRole on master role " + masterRole))
+	}
+	return nil
+}
diff --git a/pkg/postgres/postgres.go b/pkg/postgres/postgres.go
index bbe9778b..22f8f56e 100644
--- a/pkg/postgres/postgres.go
+++ b/pkg/postgres/postgres.go
@@ -53,10 +53,16 @@ func NewPG(host, user, password, uri_args, default_database, cloud_type string,
 
 	switch cloud_type {
 	case "AWS":
+		logger.Info("Using AWS wrapper")
 		return newAWSPG(postgres), nil
 	case "Azure":
+		logger.Info("Using Azure wrapper")
 		return newAzurePG(postgres), nil
+	case "GCP":
+		logger.Info("Using GCP wrapper")
+		return newGCPPG(postgres), nil
 	default:
+		logger.Info("Using default postgres implementation")
 		return postgres, nil
 	}
 }