Change crypto/rand to use math/rand in pgutil (#1589)

* Added retry logic and tests for handling if crypto/rand fails.

* Added retry logic and tests for handling if crypto/rand fails.

* Fixing linting error.

* Removing use of `crypto/rand` for use of `math/rand`.

* Changing code comment about why we ignore this error.

internal/dbutil/pgutil/db.go

@@ -20,7 +20,7 @@ type DB struct {
 
 // Open opens a postgres database with a schema
 func Open(connstr string, schemaPrefix string) (*DB, error) {
-	schemaName := schemaPrefix + "-" + RandomString(8)
+	schemaName := schemaPrefix + "-" + CreateRandomTestingSchemaName(8)
 
 	db, err := sql.Open("postgres", ConnstrWithSchema(connstr, schemaName))
 	if err != nil {

internal/dbutil/pgutil/schema.go

@@ -5,17 +5,19 @@
 package pgutil
 
 import (
-	"crypto/rand"
 	"database/sql"
 	"encoding/hex"
+	"math/rand"
 	"net/url"
 	"strconv"
 	"strings"
 )
 
-// RandomString creates a random safe string
-func RandomString(n int) string {
+// CreateRandomTestingSchemaName creates a random schema name string.
+func CreateRandomTestingSchemaName(n int) string {
 	data := make([]byte, n)
+
+	// math/rand.Read() always returns a nil error so there's no need to handle the error.
 	_, _ = rand.Read(data)
 	return hex.EncodeToString(data)
 }

internal/migrate/create_test.go

@@ -54,7 +54,7 @@ func TestCreate_Postgres(t *testing.T) {
 		t.Skipf("postgres flag missing, example:\n-postgres-test-db=%s", defaultPostgresConn)
 	}
 
-	schema := "create-" + pgutil.RandomString(8)
+	schema := "create-" + pgutil.CreateRandomTestingSchemaName(8)
 
 	db, err := sql.Open("postgres", pgutil.ConnstrWithSchema(*testPostgres, schema))
 	if err != nil {

internal/migrate/versions_test.go

@@ -34,7 +34,7 @@ func TestBasicMigrationPostgres(t *testing.T) {
 		t.Skipf("postgres flag missing, example:\n-postgres-test-db=%s", defaultPostgresConn)
 	}
 
-	schema := "create-" + pgutil.RandomString(8)
+	schema := "create-" + pgutil.CreateRandomTestingSchemaName(8)
 
 	db, err := sql.Open("postgres", pgutil.ConnstrWithSchema(*testPostgres, schema))
 	if err != nil {

internal/testplanet/run.go

@@ -21,7 +21,7 @@ import (
 
 // Run runs testplanet in multiple configurations.
 func Run(t *testing.T, config Config, test func(t *testing.T, ctx *testcontext.Context, planet *Planet)) {
-	schemaSuffix := pgutil.RandomString(8)
+	schemaSuffix := pgutil.CreateRandomTestingSchemaName(8)
 	t.Log("schema-suffix ", schemaSuffix)
 
 	for _, satelliteDB := range satellitedbtest.Databases() {

satellite/satellitedb/migrate_postgres_test.go

@@ -105,7 +105,7 @@ func TestMigratePostgres(t *testing.T) {
 
 		t.Run(strconv.Itoa(base.Version), func(t *testing.T) {
 			log := zaptest.NewLogger(t)
-			schemaName := "migrate/satellite/" + strconv.Itoa(base.Version) + pgutil.RandomString(8)
+			schemaName := "migrate/satellite/" + strconv.Itoa(base.Version) + pgutil.CreateRandomTestingSchemaName(8)
 			connstr := pgutil.ConnstrWithSchema(*satellitedbtest.TestPostgres, schemaName)
 
 			// create a new satellitedb connection

satellite/satellitedb/satellitedbtest/run.go

@@ -49,7 +49,7 @@ func Databases() []Database {
 // Run method will iterate over all supported databases. Will establish
 // connection and will create tables for each DB.
 func Run(t *testing.T, test func(t *testing.T, db satellite.DB)) {
-	schemaSuffix := pgutil.RandomString(8)
+	schemaSuffix := pgutil.CreateRandomTestingSchemaName(8)
 	t.Log("schema-suffix ", schemaSuffix)
 
 	for _, dbInfo := range Databases() {