config: Add source_file to incus_instance

Signed-off-by: Lucas Bremgartner <[email protected]>

internal/instance/resource_instance.go

@@ -3,6 +3,7 @@ package instance
 import (
 	"context"
 	"fmt"
+	"os"
 	"sort"
 	"strings"
 	"time"
@@ -29,6 +30,7 @@ import (
 	"github.com/hashicorp/terraform-plugin-sdk/v2/helper/retry"
 	incus "github.com/lxc/incus/v6/client"
 	"github.com/lxc/incus/v6/shared/api"
+	"github.com/mitchellh/go-homedir"
 
 	"github.com/lxc/terraform-provider-incus/internal/common"
 	"github.com/lxc/terraform-provider-incus/internal/errors"
@@ -52,6 +54,7 @@ type InstanceModel struct {
 	Remote         types.String `tfsdk:"remote"`
 	Target         types.String `tfsdk:"target"`
 	SourceInstance types.Object `tfsdk:"source_instance"`
+	SourceFile     types.String `tfsdk:"source_file"`
 
 	// Computed.
 	IPv4   types.String `tfsdk:"ipv4_address"`
@@ -204,6 +207,16 @@ func (r InstanceResource) Schema(_ context.Context, _ resource.SchemaRequest, re
 				},
 			},
 
+			"source_file": schema.StringAttribute{
+				Optional: true,
+				PlanModifiers: []planmodifier.String{
+					stringplanmodifier.RequiresReplace(),
+				},
+				Validators: []validator.String{
+					stringvalidator.LengthAtLeast(1),
+				},
+			},
+
 			// Computed.
 
 			"ipv4_address": schema.StringAttribute{
@@ -370,13 +383,76 @@ func (r InstanceResource) ValidateConfig(ctx context.Context, req resource.Valid
 		)
 	}
 
-	if !config.Image.IsNull() && !config.SourceInstance.IsNull() {
+	if !atMostOneOf(config.Image, config.SourceFile, config.SourceInstance) {
 		resp.Diagnostics.AddError(
 			"Invalid Configuration",
-			"Only image or source_instance can be set.",
+			"At most one of image, source_file and source_instance can be set.",
 		)
 		return
 	}
+
+	if !config.SourceFile.IsNull() {
+		// Instances from source_file are mutually exclusive with a series of other attributes.
+		if !config.Description.IsNull() ||
+			!config.Type.IsNull() ||
+			!config.Ephemeral.IsNull() ||
+			!config.Profiles.IsNull() ||
+			!config.Files.IsNull() ||
+			!config.Config.IsNull() {
+			resp.Diagnostics.AddError(
+				"Invalid Configuration",
+				"Attribute source_file is mutually exclusive with description, type, ephemeral, profiles, file and config.",
+			)
+			return
+		}
+
+		// With `incus import`, a storage pool can be provided optionally.
+		// In order to support the same behavior with source_file,
+		// a single device entry of type `disk` is allowed with exactly two properties
+		// `path` and `pool` being set. For `path`, the only accepted value is `/`.
+		if len(config.Devices.Elements()) > 0 {
+			if len(config.Devices.Elements()) > 1 {
+				resp.Diagnostics.AddError(
+					"Invalid Configuration",
+					"Only one device entry is supported with source_file.",
+				)
+				return
+			}
+
+			deviceList := make([]common.DeviceModel, 0, 1)
+			diags = config.Devices.ElementsAs(ctx, &deviceList, false)
+			if diags.HasError() {
+				resp.Diagnostics.Append(diags...)
+				return
+			}
+
+			if len(deviceList[0].Properties.Elements()) != 2 {
+				resp.Diagnostics.AddError(
+					"Invalid Configuration",
+					`Exactly two device properties named "path" and "pool" need to be provided with source_file.`,
+				)
+				return
+			}
+
+			properties := make(map[string]string, 2)
+			diags = deviceList[0].Properties.ElementsAs(ctx, &properties, false)
+			if diags.HasError() {
+				resp.Diagnostics.Append(diags...)
+				return
+			}
+
+			_, poolOK := properties["pool"]
+			path, pathOK := properties["path"]
+
+			if !poolOK || !pathOK || path != "/" {
+				resp.Diagnostics.AddError(
+					"Invalid Configuration",
+					`Exactly two device properties named "path" and "pool" need to be provided with source_file. For "path", the only accepted value is "/".`,
+				)
+				return
+			}
+		}
+	}
 }
 
 func (r InstanceResource) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) {
@@ -400,6 +476,9 @@ func (r InstanceResource) Create(ctx context.Context, req resource.CreateRequest
 	if !plan.Image.IsNull() {
 		diags = r.createInstanceFromImage(ctx, server, plan)
 		resp.Diagnostics.Append(diags...)
+	} else if !plan.SourceFile.IsNull() {
+		diags = r.createInstanceFromSourceFile(ctx, server, plan)
+		resp.Diagnostics.Append(diags...)
 	} else if !plan.SourceInstance.IsNull() {
 		diags = r.createInstanceFromSourceInstance(ctx, server, plan)
 		resp.Diagnostics.Append(diags...)
@@ -794,6 +873,13 @@ func (r InstanceResource) SyncState(ctx context.Context, tfState *tfsdk.State, s
 		return respDiags
 	}
 
+	if !m.SourceFile.IsNull() && !m.Devices.IsNull() {
+		// Using device to signal the storage pool is a special case, which is not
+		// reflected on the instance state and therefore we need to compensate here
+		// in order to prevent inconsistent provider results.
+		devices = m.Devices
+	}
+
 	m.Name = types.StringValue(instance.Name)
 	m.Type = types.StringValue(instance.Type)
 	m.Description = types.StringValue(instance.Description)
@@ -888,6 +974,66 @@ func (r InstanceResource) createInstanceFromImage(ctx context.Context, server in
 	return diags
 }
 
+func (r InstanceResource) createInstanceFromSourceFile(ctx context.Context, server incus.InstanceServer, plan InstanceModel) diag.Diagnostics {
+	var diags diag.Diagnostics
+
+	name := plan.Name.ValueString()
+
+	var poolName string
+
+	if len(plan.Devices.Elements()) > 0 {
+		// Only one device is expected, this is ensured by ValidateConfig.
+		deviceList := make([]common.DeviceModel, 0, 1)
+		diags = plan.Devices.ElementsAs(ctx, &deviceList, false)
+		if diags.HasError() {
+			return diags
+		}
+
+		// Exactly two properties named "path" and "pool" are expected, this is ensured by ValidateConfig.
+		properties := make(map[string]string, 2)
+		diags = deviceList[0].Properties.ElementsAs(ctx, &properties, false)
+		if diags.HasError() {
+			return diags
+		}
+
+		poolName = properties["pool"]
+	}
+
+	srcFile := plan.SourceFile.ValueString()
+
+	path, err := homedir.Expand(srcFile)
+	if err != nil {
+		diags.AddError(fmt.Sprintf("Failed to determine source_file: %q", srcFile), err.Error())
+		return diags
+	}
+
+	file, err := os.Open(path)
+	if err != nil {
+		diags.AddError(fmt.Sprintf("Failed to open source_file: %q", path), err.Error())
+		return diags
+	}
+
+	defer func() { _ = file.Close() }()
+
+	createArgs := incus.InstanceBackupArgs{
+		BackupFile: file,
+		PoolName:   poolName,
+		Name:       name,
+	}
+
+	op, err := server.CreateInstanceFromBackup(createArgs)
+	if err == nil {
+		err = op.Wait()
+	}
+
+	if err != nil {
+		diags.AddError(fmt.Sprintf("Failed to create instance: %q", name), err.Error())
+		return diags
+	}
+
+	return diags
+}
+
 func (r InstanceResource) createInstanceFromSourceInstance(ctx context.Context, destServer incus.InstanceServer, plan InstanceModel) diag.Diagnostics {
 	var diags diag.Diagnostics
 	var sourceInstanceModel SourceInstanceModel
@@ -1426,3 +1572,13 @@ func getAddresses(name string, entry api.InstanceStateNetwork) (string, string,
 
 	return ipv4, ipv6, entry.Hwaddr, name, true
 }
+
+func atMostOneOf(in ...interface{ IsNull() bool }) bool {
+	var count int
+	for _, v := range in {
+		if !v.IsNull() {
+			count++
+		}
+	}
+	return count <= 1
+}