feat: Add PostgreSQL 18 driver + driver refactor by Unbreathable · Pull Request #33 · Liphium/magic

Unbreathable · 2026-03-05T13:37:14Z

Description

This MR adds a PostgreSQL driver in the new pkg/databases directory for drivers that supports PostgreSQL 18 and its new container layout
The basic container lifecycle has been moved to a new mservices package for more easily creating drivers
The PostgreSQL legacy driver has been upgraded to use the new API (will be maintained until PostgreSQL 20 is out)
The real-project example has been updated to use the new PostgreSQL 18 driver

Copilot

Pull request overview

Adds a new PostgreSQL 18 service driver under pkg/databases/postgres, refactors Docker container lifecycle logic into reusable mrunner/services helpers, and migrates the legacy driver + real-project example to the new API.

Changes:

Introduce new PostgreSQL 18 driver (pkg/databases/postgres) with container lifecycle, health checks, initialization, and instruction handling.
Add mrunner/services helpers for managed container create/recreate + container exec, and update the legacy driver to use them.
Update examples/real-project to use the new PostgreSQL 18 driver.

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated 13 comments.

Show a summary per file

File	Description
pkg/databases/postgres/postgres.go	New PostgreSQL 18 driver implementation and config helpers
pkg/databases/postgres/postgres_container.go	Container creation/health/init for new driver via `mservices`
pkg/databases/postgres/postgres_instruct.go	Clear/drop table instructions for new driver
pkg/databases/postgres/go.mod	New submodule definition for postgres driver
pkg/databases/postgres/go.sum	Dependency locks for new postgres submodule
pkg/databases/postgres-legacy/postgres_legacy_container.go	Refactored legacy container lifecycle to use `mservices` helpers
pkg/databases/postgres-legacy/postgres_legacy.go	Updated legacy driver docs/comments
pkg/databases/postgres-legacy/go.mod	Dependency cleanup / reclassification (direct -> indirect)
mrunner/services/containers.go	New shared “managed container” creation/recreate logic
mrunner/services/containers_exec.go	New shared helper to exec commands in containers
go.work	Add postgres driver submodule to workspace
examples/real-project/starter/config.go	Switch example to new postgres (18) driver
examples/real-project/go.mod	Switch example module dependency/replace to new postgres driver

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Copilot · 2026-03-05T13:50:14Z

pkg/databases/postgres-legacy/postgres_legacy_container.go

+		Env: []string{
+			fmt.Sprintf("POSTGRES_PASSWORD=%s", PostgresPassword),
+			fmt.Sprintf("POSTGRES_USER=%s", PostgresUsername),
+			"POSTGRES_DATABASE=postgres",


The official postgres image uses POSTGRES_DB (not POSTGRES_DATABASE) to set the initial database name. With standard images this env var will be ignored. Consider switching to POSTGRES_DB=postgres (or removing it if the default is sufficient).

Suggested change

"POSTGRES_DATABASE=postgres",

"POSTGRES_DB=postgres",

Copilot · 2026-03-05T13:50:15Z

pkg/databases/postgres/go.mod

+module github.com/Liphium/magic/pkg/databases/postgres
+
+go 1.25.7
+
+replace github.com/Liphium/magic/v3 => ../../../.


The module path in this new submodule doesn’t match how it’s imported elsewhere (e.g. github.com/Liphium/magic/v3/pkg/databases/postgres). With the current module github.com/Liphium/magic/pkg/databases/postgres, go will error with “module declares its path as … but was required as …” when consumers require/import the /v3/... path. Update the module line to the exact import path you expect users to require (likely github.com/Liphium/magic/v3/pkg/databases/postgres) and keep go.work/consumer replace directives aligned to it.

Copilot · 2026-03-05T13:50:15Z

examples/real-project/go.mod

 replace github.com/Liphium/magic/v3 => ../../.

-replace github.com/Liphium/magic/v3/pkg/databases/postgres-legacy => ../../pkg/databases/postgres-legacy
+replace github.com/Liphium/magic/v3/pkg/databases/postgres => ../../pkg/databases/postgres

 require (
 	github.com/Liphium/magic/v3 v3.0.0-00010101000000-000000000000
-	github.com/Liphium/magic/v3/pkg/databases/postgres-legacy v0.0.0-00010101000000-000000000000
+	github.com/Liphium/magic/v3/pkg/databases/postgres v0.0.0-00010101000000-000000000000
 	github.com/gofiber/fiber/v2 v2.52.9


This example requires/replaces github.com/Liphium/magic/v3/pkg/databases/postgres, but the pkg/databases/postgres submodule’s go.mod currently declares a different module path. As-is, go mod resolution will fail with a module-path mismatch error. Align the driver submodule module path (and/or this require/replace) so they match exactly.

Copilot · 2026-03-05T13:50:15Z

mrunner/services/containers_exec.go

+		return client.ExecInspectResult{}, fmt.Errorf("couldn't create command for readiness of container: %s", err)
+	}
+	execStartCheck := client.ExecStartOptions{Detach: false, TTY: false}
+	if _, err := c.ExecStart(ctx, execIDResp.ID, execStartCheck); err != nil {
+		return client.ExecInspectResult{}, fmt.Errorf("couldn't start command for readiness of container: %s", err)


ExecuteCommand is a generic helper, but all error messages mention “readiness of container”. This makes debugging confusing when the helper is used for non-readiness execs. Consider changing these error strings to be command-agnostic (e.g. “couldn't create exec”, “couldn't start exec”).

Suggested change

return client.ExecInspectResult{}, fmt.Errorf("couldn't create command for readiness of container: %s", err)

}

execStartCheck := client.ExecStartOptions{Detach: false, TTY: false}

if _, err := c.ExecStart(ctx, execIDResp.ID, execStartCheck); err != nil {

return client.ExecInspectResult{}, fmt.Errorf("couldn't start command for readiness of container: %s", err)

return client.ExecInspectResult{}, fmt.Errorf("couldn't create exec: %s", err)

}

execStartCheck := client.ExecStartOptions{Detach: false, TTY: false}

if _, err := c.ExecStart(ctx, execIDResp.ID, execStartCheck); err != nil {

return client.ExecInspectResult{}, fmt.Errorf("couldn't start exec: %s", err)

Copilot · 2026-03-05T13:50:16Z

pkg/databases/postgres/postgres_instruct.go

+			// Get all of the tables
+			res, err := conn.Query("SELECT table_name FROM information_schema.tables WHERE table_schema NOT IN ('pg_catalog', 'information_schema')")
+			if err != nil {
+				return fmt.Errorf("couldn't get database tables: %v", err)
+			}
+			for res.Next() {
+				var name string
+				if err := res.Scan(&name); err != nil {
+					return fmt.Errorf("couldn't get database table name: %v", err)
+				}
+				if err := fn(name, conn); err != nil {
+					return err
+				}
+			}
+
+			return nil


iterateTables doesn’t close the Rows result or check Rows.Err() after iteration. This can leak resources and can silently ignore iteration errors. Add a defer res.Close() after a successful Query, and check res.Err() after the for res.Next() loop.

Copilot · 2026-03-05T13:50:17Z

pkg/databases/postgres/postgres_container.go

+		Env: []string{
+			fmt.Sprintf("POSTGRES_PASSWORD=%s", PostgresPassword),
+			fmt.Sprintf("POSTGRES_USER=%s", PostgresUsername),
+			"POSTGRES_DATABASE=postgres",


The official postgres image uses POSTGRES_DB (not POSTGRES_DATABASE) to set the initial database name. As written, this env var will be ignored by standard images, which is confusing and makes it look like the DB name is configurable when it isn’t. Consider switching to POSTGRES_DB=postgres (or dropping it entirely since postgres is the default).

Suggested change

"POSTGRES_DATABASE=postgres",

"POSTGRES_DB=postgres",

Copilot · 2026-03-05T13:50:17Z

pkg/databases/postgres/postgres_instruct.go

+	return pd.iterateTables(container, func(tableName string, conn *sql.DB) error {
+		if _, err := conn.Exec(fmt.Sprintf("truncate %s CASCADE", tableName)); err != nil {
+			return fmt.Errorf("couldn't truncate table %s: %v", tableName, err)
+		}


tableName is interpolated directly into the TRUNCATE statement. Even though it comes from information_schema, unquoted identifiers can break on mixed-case/reserved-word table names and can be abused if a table name contains SQL metacharacters. Use proper identifier quoting (e.g. quote_ident) and/or include schema + table and quote both parts before executing.

Copilot · 2026-03-05T13:50:17Z

pkg/databases/postgres/postgres_instruct.go

+	return pd.iterateTables(container, func(tableName string, conn *sql.DB) error {
+		if _, err := conn.Exec(fmt.Sprintf("DROP TABLE %s CASCADE", tableName)); err != nil {
+			return fmt.Errorf("couldn't drop table table %s: %v", tableName, err)
+		}


tableName is interpolated directly into the DROP TABLE statement. Unquoted identifiers can fail for many valid table names (reserved words, mixed case, special chars) and can allow SQL injection if a maliciously named table exists. Quote identifiers (and ideally schema + table) before executing.

Copilot · 2026-03-05T13:50:17Z

pkg/databases/postgres/postgres_instruct.go

+func (pd *PostgresDriver) DropTables(container mconfig.ContainerInformation) error {
+	return pd.iterateTables(container, func(tableName string, conn *sql.DB) error {
+		if _, err := conn.Exec(fmt.Sprintf("DROP TABLE %s CASCADE", tableName)); err != nil {
+			return fmt.Errorf("couldn't drop table table %s: %v", tableName, err)


Typo in error message: duplicated word “table”.

Suggested change

return fmt.Errorf("couldn't drop table table %s: %v", tableName, err)

return fmt.Errorf("couldn't drop table %s: %v", tableName, err)

Copilot · 2026-03-05T13:50:18Z

pkg/databases/postgres/postgres.go

+	"strings"
+
+	"github.com/Liphium/magic/v3/mconfig"
+	"github.com/Liphium/magic/v3/util"


This driver calls sql.Open("postgres", ...) but the package doesn’t import/register any Postgres database/sql driver (e.g. blank-importing github.com/lib/pq). Right now it implicitly relies on some other package (like mrunner) to have side-effect imports, which makes the driver easy to use incorrectly and can lead to runtime sql: unknown driver "postgres" errors in other integration paths. Consider adding the blank import here (and adding the dependency in this submodule) so the driver is self-contained, matching the legacy driver’s pattern.

Suggested change

"github.com/Liphium/magic/v3/util"

"github.com/Liphium/magic/v3/util"

_ "github.com/lib/pq"

feat: Add PostgreSQL 18 driver + upgrade real project example

5f00260

Unbreathable added this to the Magic v3 milestone Mar 5, 2026

Unbreathable self-assigned this Mar 5, 2026

Unbreathable linked an issue Mar 5, 2026 that may be closed by this pull request

Postgres Version 18 Support #23

Open

Unbreathable requested a review from Copilot March 5, 2026 13:37

Copilot started reviewing on behalf of Unbreathable March 5, 2026 13:38 View session

Copilot AI reviewed Mar 5, 2026

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feat: Add PostgreSQL 18 driver + driver refactor#33

feat: Add PostgreSQL 18 driver + driver refactor#33
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feat/postgres-18

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	return fmt.Errorf("couldn't drop table table %s: %v", tableName, err)
	return fmt.Errorf("couldn't drop table %s: %v", tableName, err)

	"github.com/Liphium/magic/v3/util"
	"github.com/Liphium/magic/v3/util"
	_ "github.com/lib/pq"

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Unbreathable commented Mar 5, 2026

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