Provide a new command, gof3r info, which fetches metadata about an ob…

…ject.

The new command will print some small bits of metadata about an object on
success and will exit with a non-zero exit code on failure. The info command
can be used to query for a file's existence without downloading it, and
performs only a HEAD request.

Fixes #71

getter.go

@@ -307,6 +307,35 @@ func (g *getter) Close() error {
 	return nil
 }
 
+func GetInfo(b *Bucket, c *Config, key string, version string) (*http.Response, error) {
+	urlStr, err := b.url(key, c)
+
+    if err != nil {
+        return nil, err
+    }
+
+	for i := 0; i < c.NTry; i++ {
+		var req *http.Request
+        req, err := http.NewRequest("HEAD", urlStr.String(), nil)
+
+		if err != nil {
+			return nil, err
+		}
+
+		b.Sign(req)
+
+        resp, err := c.Client.Do(req)
+
+		if err != nil {
+			return nil, err
+		}
+
+        return resp, nil
+	}
+
+    return nil, fmt.Errorf("Could not get info.")
+}
+
 func (g *getter) checkMd5() (err error) {
 	calcMd5 := fmt.Sprintf("%x", g.md5.Sum(nil))
 	md5Path := fmt.Sprint(".md5", g.url.Path, ".md5")

gof3r/info.go

@@ -0,0 +1,60 @@
+package main
+
+import (
+    "log"
+
+	"github.com/rlmcpherson/s3gof3r"
+)
+
+var info infoOpts
+
+type infoOpts struct {
+	Key    string `long:"key" short:"k" description:"S3 object key" required:"true" no-ini:"true"`
+	Bucket string `long:"bucket" short:"b" description:"S3 bucket" required:"true" no-ini:"true"`
+	VersionID string `short:"v" long:"versionId" description:"Version ID of the object. Incompatible with md5 check (use --no-md5)." no-ini:"true"`
+}
+
+func (info *infoOpts) Execute(args []string) (err error) {
+	conf := new(s3gof3r.Config)
+	*conf = *s3gof3r.DefaultConfig
+	k, err := getAWSKeys()
+	if err != nil {
+		return err
+	}
+
+	s3 := s3gof3r.New(get.EndPoint, k)
+	b := s3.Bucket(info.Bucket)
+	conf.Concurrency = get.Concurrency
+
+	if get.NoSSL {
+		conf.Scheme = "http"
+	}
+
+    resp, err := s3gof3r.GetInfo(b, s3gof3r.DefaultConfig, info.Key, info.VersionID)
+
+    if err != nil {
+        return err
+    }
+
+    if resp.StatusCode >= 200 && resp.StatusCode < 300 {
+        log.Println("Found object:")
+        log.Println("  Status: ", resp.StatusCode)
+        log.Println("  Last-Modified: ", resp.Header["Last-Modified"])
+        log.Println("  Size: ", resp.Header["Content-Length"])
+    } else if resp.StatusCode == 403 {
+        log.Fatal("Access Denied")
+    } else {
+        log.Fatal("Non-2XX status code: ", resp.StatusCode)
+    }
+
+    return nil
+}
+
+func init() {
+	_, err := parser.AddCommand("info", "check info from S3", "get information about an object from S3", &info)
+
+	if err != nil {
+		log.Fatal(err)
+	}
+}
+

gof3r/main_test.go

@@ -35,6 +35,15 @@ var flagTests = []flagTest{
 		errors.New("expected argument for flag")},
 	{[]string{"gof3r", "get"},
 		errors.New("required flags")},
+    {[]string{"gof3r", "info"},
+        errors.New("required flags")},
+    {[]string{"gof3r", "info", "-b"},
+        errors.New("expected argument for flag")},
+	{[]string{"gof3r", "info", "-b", "fake-bucket", "-k", "test-key"},
+		errors.New("Access Denied")},
+	{[]string{"gof3r", "info", "-b", "fake-bucket", "-k", "key",
+		"-c", "1", "-s", "1024", "--debug", "--no-ssl", "--no-md5"},
+		errors.New("Access Denied")},
 }
 
 func TestFlags(t *testing.T) {