feat(pre-deploy): add support for x-pre_deploy extension in Compose + e2e test

pkg/client/compose/predeploy.go

@@ -0,0 +1,26 @@
+package compose
+
+import (
+	"fmt"
+
+	"github.com/compose-spec/compose-go/v2/types"
+)
+
+const PreDeployHookExtensionKey = "x-pre_deploy"
+
+// PreDeployHook represents the parsed x-pre_deploy extension config.
+type PreDeployHook struct {
+	Command     types.ShellCommand      `yaml:"command" json:"command"`
+	Environment types.MappingWithEquals `yaml:"environment,omitempty" json:"environment,omitempty"`
+	Privileged  *bool                   `yaml:"privileged,omitempty" json:"privileged,omitempty"`
+	Timeout     *types.Duration         `yaml:"timeout,omitempty" json:"timeout,omitempty"`
+	User        string                  `yaml:"user,omitempty" json:"user,omitempty"`
+}
+
+// Validate checks that the pre-deploy hook configuration is valid.
+func (p *PreDeployHook) Validate() error {
+	if len(p.Command) == 0 {
+		return fmt.Errorf("missing required attribute 'command' in %s extension", PreDeployHookExtensionKey)
+	}
+	return nil
+}