api,disk: add filesystem endpoints

api/api.go

@@ -139,6 +139,7 @@ func NewServer(hostKey types.PublicKey, g Syncer, chain ChainManager, cm Contrac
 		"GET /wallet/transactions":        a.handleGETWalletTransactions,
 		"GET /wallet/pending":             a.handleGETWalletPending,
 		"POST /wallet/send":               a.handlePOSTWalletSend,
+		"GET /system/dir/:path":           a.handleGETSystemDir,
 	})
 	return r
 }

api/endpoints.go

@@ -5,13 +5,15 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"os"
 	"time"
 
 	"go.sia.tech/core/types"
 	"go.sia.tech/hostd/host/contracts"
 	"go.sia.tech/hostd/host/metrics"
 	"go.sia.tech/hostd/host/settings"
 	"go.sia.tech/hostd/host/storage"
+	"go.sia.tech/hostd/internal/disk"
 	"go.sia.tech/jape"
 	"go.sia.tech/siad/modules"
 	"go.uber.org/zap"
@@ -354,6 +356,40 @@ func (a *API) handlePOSTWalletSend(c jape.Context) {
 	c.Error(errors.New("not implemented"), http.StatusInternalServerError)
 }
 
+func (a *API) handleGETSystemDir(c jape.Context) {
+	var path string
+	if err := c.DecodeParam("path", &path); err != nil {
+		c.Error(fmt.Errorf("failed to parse path: %w", err), http.StatusBadRequest)
+	} else if len(path) == 0 {
+		path, _ = os.UserHomeDir()
+	}
+
+	dir, err := os.ReadDir(path)
+	if errors.Is(err, os.ErrNotExist) {
+		c.Error(fmt.Errorf("path does not exist: %w", err), http.StatusBadRequest)
+		return
+	} else if !a.checkServerError(c, "failed to read dir", err) {
+		return
+	}
+
+	free, total, err := disk.Usage(path)
+	if !a.checkServerError(c, "failed to get disk usage", err) {
+		return
+	}
+
+	resp := SystemDirResponse{
+		FreeBytes:  free,
+		TotalBytes: total,
+	}
+
+	for _, entry := range dir {
+		if entry.IsDir() {
+			resp.Directories = append(resp.Directories, entry.Name())
+		}
+	}
+	c.Encode(resp)
+}
+
 func parseLimitParams(c jape.Context, defaultLimit, maxLimit int) (limit, offset int) {
 	c.DecodeForm("limit", &limit)
 	c.DecodeForm("offset", &offset)

api/openapi.yml

@@ -273,6 +273,36 @@ paths:
                 type: array
                 items:
                   $ref: '#/components/schemas/Transaction'
+  /system/dir/{path}:
+    get:
+      summary: Retrieve system directory information
+      operationId: getSystemDir
+      parameters:
+        - name: path
+          in: path
+          required: true
+          schema:
+            type: string
+          description: The path of the directory to retrieve information about
+      responses:
+        '200':
+          description: Successfully retrieved directory information
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/SystemDirResponse'
+        '400':
+          description: Bad request (invalid path)
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
+        '500':
+          description: Internal server error
+          content:
+            application/json:
+              schema:
+                $ref: '#/components/schemas/Error'
 
 components:
   securitySchemes:
@@ -582,4 +612,22 @@ components:
         confirmed:
           type: string
         unconfirmed:
+          type: string
+    SystemDirResponse:
+      type: object
+      properties:
+        totalBytes:
+          type: integer
+          format: uint64
+        freeBytes:
+          type: integer
+          format: uint64
+        directories:
+          type: array
+          items:
+            type: string
+    Error:
+      type: object
+      properties:
+        error:
           type: string

api/types.go

@@ -80,6 +80,13 @@ type (
 	// UpdateSettingsRequest is the request body for the [PUT] /settings
 	// endpoint. It will be merged with the current settings.
 	UpdateSettingsRequest map[string]any
+
+	// SystemDirResponse is the response body for the [GET] /system/dir endpoint.
+	SystemDirResponse struct {
+		TotalBytes  uint64   `json:"totalBytes"`
+		FreeBytes   uint64   `json:"freeBytes"`
+		Directories []string `json:"directories"`
+	}
 )
 
 // WithAcceptingContracts sets the AcceptingContracts field of the request

go.mod

@@ -14,6 +14,7 @@ require (
 	go.sia.tech/siad v1.5.10-0.20230228235644-3059c0b930ca
 	go.sia.tech/web/hostd v0.0.0-20230330233636-9ae27b2629a4
 	go.uber.org/zap v1.24.0
+	golang.org/x/sys v0.7.0
 	golang.org/x/term v0.5.0
 	golang.org/x/time v0.3.0
 	lukechampine.com/frand v1.4.2
@@ -60,7 +61,6 @@ require (
 	go.uber.org/multierr v1.8.0 // indirect
 	golang.org/x/crypto v0.5.0 // indirect
 	golang.org/x/net v0.7.0 // indirect
-	golang.org/x/sys v0.5.0 // indirect
 	golang.org/x/text v0.7.0 // indirect
 	golang.org/x/tools v0.5.0 // indirect
 	google.golang.org/genproto v0.0.0-20221118155620-16455021b5e6 // indirect

go.sum

@@ -479,8 +479,8 @@ golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBc
 golang.org/x/sys v0.0.0-20220704084225-05e143d24a9e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
-golang.org/x/sys v0.5.0 h1:MUK/U/4lj1t1oPg0HfuXDN/Z1wv31ZJ/YcPiGccS4DU=
-golang.org/x/sys v0.5.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.7.0 h1:3jlCCIQZPdOYu1h8BkNvLz8Kgwtae2cagcG/VamtZRU=
+golang.org/x/sys v0.7.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210421210424-b80969c67360/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=

internal/disk/disk.go

@@ -0,0 +1,2 @@
+// Package disk provides cross platform disk usage information
+package disk

internal/disk/disk_test.go

@@ -0,0 +1,18 @@
+package disk
+
+import (
+	"os"
+	"testing"
+)
+
+func TestUsage(t *testing.T) {
+	dir, err := os.UserHomeDir()
+	if err != nil {
+		t.Fatal(err)
+	}
+	free, total, err := Usage(dir)
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Logf("%s - %d/%d bytes", dir, free, total)
+}

internal/disk/usage_default.go

@@ -0,0 +1,15 @@
+//go:build !windows
+
+package disk
+
+import "syscall"
+
+// Usage returns the free and total bytes on the filesystem containing the
+// specified path.
+func Usage(p string) (free, total uint64, err error) {
+	var stat syscall.Statfs_t
+	if err := syscall.Statfs(p, &stat); err != nil {
+		return 0, 0, err
+	}
+	return stat.Bfree * uint64(stat.Bsize), stat.Blocks * uint64(stat.Bsize), nil
+}

internal/disk/usage_windows.go

@@ -0,0 +1,25 @@
+//go:build windows
+
+package disk
+
+import (
+	"fmt"
+	"os"
+
+	"golang.org/x/sys/windows"
+)
+
+// Usage returns the free and totreal bytes on the filesystem containing the
+// specified path.
+func Usage(p string) (free, total uint64, err error) {
+	if _, err = os.Stat(p); err != nil {
+		return 0, 0, fmt.Errorf("failed to stat %v: %v", p, err)
+	}
+
+	ptr, err := windows.UTF16PtrFromString(p)
+	if err != nil {
+		panic(err)
+	}
+	err = windows.GetDiskFreeSpaceEx(ptr, &free, &total, nil)
+	return
+}