package pg import ( "context" "database/sql" "fmt" "github.com/hashicorp/terraform/backend" "github.com/hashicorp/terraform/internal/legacy/helper/schema" "github.com/lib/pq" ) const ( statesTableName = "states" statesIndexName = "states_by_name" ) // New creates a new backend for Postgres remote state. func New() backend.Backend { s := &schema.Backend{ Schema: map[string]*schema.Schema{ "conn_str": { Type: schema.TypeString, Required: true, Description: "Postgres connection string; a `postgres://` URL", }, "schema_name": { Type: schema.TypeString, Optional: true, Description: "Name of the automatically managed Postgres schema to store state", Default: "terraform_remote_state", }, "skip_schema_creation": { Type: schema.TypeBool, Optional: true, Description: "If set to `true`, Terraform won't try to create the Postgres schema", Default: false, }, "skip_table_creation": { Type: schema.TypeBool, Optional: true, Description: "If set to `true`, Terraform won't try to create the Postgres table", }, "skip_index_creation": { Type: schema.TypeBool, Optional: true, Description: "If set to `true`, Terraform won't try to create the Postgres index", }, }, } result := &Backend{Backend: s} result.Backend.ConfigureFunc = result.configure return result } type Backend struct { *schema.Backend // The fields below are set from configure db *sql.DB configData *schema.ResourceData connStr string schemaName string } func (b *Backend) configure(ctx context.Context) error { // Grab the resource data b.configData = schema.FromContextBackendConfig(ctx) data := b.configData b.connStr = data.Get("conn_str").(string) b.schemaName = pq.QuoteIdentifier(data.Get("schema_name").(string)) db, err := sql.Open("postgres", b.connStr) if err != nil { return err } // Prepare database schema, tables, & indexes. var query string if !data.Get("skip_schema_creation").(bool) { // list all schemas to see if it exists var count int query = `select count(1) from information_schema.schemata where schema_name = $1` if err := db.QueryRow(query, data.Get("schema_name").(string)).Scan(&count); err != nil { return err } // skip schema creation if schema already exists // `CREATE SCHEMA IF NOT EXISTS` is to be avoided if ever // a user hasn't been granted the `CREATE SCHEMA` privilege if count < 1 { // tries to create the schema query = `CREATE SCHEMA IF NOT EXISTS %s` if _, err := db.Exec(fmt.Sprintf(query, b.schemaName)); err != nil { return err } } } if !data.Get("skip_table_creation").(bool) { query = `CREATE TABLE IF NOT EXISTS %s.%s ( id SERIAL PRIMARY KEY, name TEXT, data TEXT )` if _, err := db.Exec(fmt.Sprintf(query, b.schemaName, statesTableName)); err != nil { return err } } if !data.Get("skip_index_creation").(bool) { query = `CREATE UNIQUE INDEX IF NOT EXISTS %s ON %s.%s (name)` if _, err := db.Exec(fmt.Sprintf(query, statesIndexName, b.schemaName, statesTableName)); err != nil { return err } } // Assign db after its schema is prepared. b.db = db return nil }