Add snat/netmap/nat provider resources

Add tomswallapi_snat, tomswallapi_netmap, and tomswallapi_nat resources for the
NAT tier, following the id-keyed rule-resource pattern (POST create, GET/DELETE
by id, update via delete+recreate since the API is create/delete only, import by
id). Register them, document them in the README, and add examples.

internal/provider/resource_netmap.go

@@ -0,0 +1,173 @@
+package provider
+
+import (
+	"context"
+	"strconv"
+
+	"github.com/hashicorp/terraform-plugin-framework/path"
+	"github.com/hashicorp/terraform-plugin-framework/resource"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/int64planmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+)
+
+var (
+	_ resource.Resource                = &netmapResource{}
+	_ resource.ResourceWithImportState = &netmapResource{}
+)
+
+type netmapResource struct{ client *apiClient }
+
+type netmapModel struct {
+	ID      types.Int64  `tfsdk:"id"`
+	Type    types.String `tfsdk:"type"`
+	FromNet types.String `tfsdk:"from_net"`
+	ToNet   types.String `tfsdk:"to_net"`
+	Anchor  types.String `tfsdk:"anchor"`
+	Comment types.String `tfsdk:"comment"`
+}
+
+type netmapAPI struct {
+	ID      int64  `json:"id,omitempty"`
+	Type    string `json:"type"`
+	FromNet string `json:"from_net"`
+	ToNet   string `json:"to_net"`
+	Anchor  string `json:"anchor"`
+	Comment string `json:"comment,omitempty"`
+}
+
+func NewNetmapResource() resource.Resource { return &netmapResource{} }
+
+func (r *netmapResource) Metadata(_ context.Context, req resource.MetadataRequest, resp *resource.MetadataResponse) {
+	resp.TypeName = req.ProviderTypeName + "_netmap"
+}
+
+func (r *netmapResource) Schema(_ context.Context, _ resource.SchemaRequest, resp *resource.SchemaResponse) {
+	resp.Schema = schema.Schema{
+		Description: "A network-to-network mapping (netmap), anchored at a device:zone or device:interface. It renders on the anchored device with the zone resolved to its bound interface.",
+		Attributes: map[string]schema.Attribute{
+			"id": schema.Int64Attribute{
+				Description:   "Server-assigned id.",
+				Computed:      true,
+				PlanModifiers: []planmodifier.Int64{int64planmodifier.UseStateForUnknown()},
+			},
+			"type": schema.StringAttribute{
+				Description: "dnat or snat.",
+				Required:    true,
+			},
+			"from_net": schema.StringAttribute{
+				Description: "Network (CIDR) to match.",
+				Required:    true,
+			},
+			"to_net": schema.StringAttribute{
+				Description: "Network (CIDR) to rewrite to.",
+				Required:    true,
+			},
+			"anchor": schema.StringAttribute{
+				Description: "Anchor as device:zone or device:interface.",
+				Required:    true,
+			},
+			"comment": schema.StringAttribute{Optional: true},
+		},
+	}
+}
+
+func (r *netmapResource) Configure(_ context.Context, req resource.ConfigureRequest, resp *resource.ConfigureResponse) {
+	r.client = configureClient(req, resp)
+}
+
+func (r *netmapResource) body(plan netmapModel) netmapAPI {
+	return netmapAPI{
+		Type:    plan.Type.ValueString(),
+		FromNet: plan.FromNet.ValueString(),
+		ToNet:   plan.ToNet.ValueString(),
+		Anchor:  plan.Anchor.ValueString(),
+		Comment: plan.Comment.ValueString(),
+	}
+}
+
+func (r *netmapResource) Create(ctx context.Context, req resource.CreateRequest, resp *resource.CreateResponse) {
+	var plan netmapModel
+	resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+	var out netmapAPI
+	if err := r.client.post(ctx, "/api/v1/netmap", r.body(plan), &out); err != nil {
+		resp.Diagnostics.AddError("create netmap failed", err.Error())
+		return
+	}
+	resp.Diagnostics.Append(resp.State.Set(ctx, r.toModel(out, plan))...)
+}
+
+// Update: the netmap API is create/delete only, so recreate and delete the old id.
+func (r *netmapResource) Update(ctx context.Context, req resource.UpdateRequest, resp *resource.UpdateResponse) {
+	var plan, state netmapModel
+	resp.Diagnostics.Append(req.Plan.Get(ctx, &plan)...)
+	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+	var out netmapAPI
+	if err := r.client.post(ctx, "/api/v1/netmap", r.body(plan), &out); err != nil {
+		resp.Diagnostics.AddError("recreate netmap failed", err.Error())
+		return
+	}
+	if id := state.ID.ValueInt64(); id != 0 {
+		if err := r.client.del(ctx, "/api/v1/netmap/"+strconv.FormatInt(id, 10)); err != nil && !isNotFound(err) {
+			resp.Diagnostics.AddError("delete old netmap failed", err.Error())
+			return
+		}
+	}
+	resp.Diagnostics.Append(resp.State.Set(ctx, r.toModel(out, plan))...)
+}
+
+func (r *netmapResource) Read(ctx context.Context, req resource.ReadRequest, resp *resource.ReadResponse) {
+	var state netmapModel
+	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+	var out netmapAPI
+	if err := r.client.get(ctx, "/api/v1/netmap/"+strconv.FormatInt(state.ID.ValueInt64(), 10), &out); err != nil {
+		if isNotFound(err) {
+			resp.State.RemoveResource(ctx)
+			return
+		}
+		resp.Diagnostics.AddError("read netmap failed", err.Error())
+		return
+	}
+	resp.Diagnostics.Append(resp.State.Set(ctx, r.toModel(out, state))...)
+}
+
+func (r *netmapResource) Delete(ctx context.Context, req resource.DeleteRequest, resp *resource.DeleteResponse) {
+	var state netmapModel
+	resp.Diagnostics.Append(req.State.Get(ctx, &state)...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+	if err := r.client.del(ctx, "/api/v1/netmap/"+strconv.FormatInt(state.ID.ValueInt64(), 10)); err != nil && !isNotFound(err) {
+		resp.Diagnostics.AddError("delete netmap failed", err.Error())
+	}
+}
+
+func (r *netmapResource) ImportState(ctx context.Context, req resource.ImportStateRequest, resp *resource.ImportStateResponse) {
+	id, err := strconv.ParseInt(req.ID, 10, 64)
+	if err != nil {
+		resp.Diagnostics.AddError("invalid import ID", "netmap id must be an integer")
+		return
+	}
+	resp.Diagnostics.Append(resp.State.SetAttribute(ctx, path.Root("id"), id)...)
+}
+
+func (r *netmapResource) toModel(api netmapAPI, prior netmapModel) netmapModel {
+	return netmapModel{
+		ID:      types.Int64Value(api.ID),
+		Type:    types.StringValue(api.Type),
+		FromNet: types.StringValue(api.FromNet),
+		ToNet:   types.StringValue(api.ToNet),
+		Anchor:  types.StringValue(api.Anchor),
+		Comment: optionalString(api.Comment, prior.Comment),
+	}
+}