fix and improve the writable gateway

1. Fix handling of PUT. The simple implementation was the correct
   implementation, I have no idea what was going on here.
2. Use MFS everywhere to reduce code duplication and add support for sharded
   directories.
3. _Correctly_ block IPNS.
4. Remove the dependency on `core.IpfsNode`.
5. Remove support for putting empty directories with a well-known CID. It was
   useless as directories are automatically created.

core/corehttp/gateway.go

@@ -87,7 +87,7 @@ func GatewayOption(writable bool, paths ...string) ServeOption {
 				"X-Stream-Output",
 			}, headers[ACEHeadersName]...))
 
-		gateway := newGatewayHandler(n, GatewayConfig{
+		gateway := newGatewayHandler(GatewayConfig{
 			Headers:      headers,
 			Writable:     writable,
 			PathPrefixes: cfg.Gateway.PathPrefixes,

go.mod

@@ -45,12 +45,12 @@ require (
 	github.com/ipfs/go-ipld-git v0.0.2
 	github.com/ipfs/go-ipns v0.0.1
 	github.com/ipfs/go-log v0.0.1
-	github.com/ipfs/go-merkledag v0.2.0
+	github.com/ipfs/go-merkledag v0.2.3
 	github.com/ipfs/go-metrics-interface v0.0.1
 	github.com/ipfs/go-metrics-prometheus v0.0.2
 	github.com/ipfs/go-mfs v0.1.0
 	github.com/ipfs/go-path v0.0.7
-	github.com/ipfs/go-unixfs v0.2.0
+	github.com/ipfs/go-unixfs v0.2.1
 	github.com/ipfs/go-verifcid v0.0.1
 	github.com/ipfs/hang-fds v0.0.1
 	github.com/ipfs/interface-go-ipfs-core v0.1.0

go.sum

@@ -301,6 +301,8 @@ github.com/ipfs/go-merkledag v0.1.0 h1:CAEXjRFEDPvealQj3TgEjV1IJckwjvmxAqtq5QSXJ
 github.com/ipfs/go-merkledag v0.1.0/go.mod h1:SQiXrtSts3KGNmgOzMICy5c0POOpUNQLvB3ClKnBAlk=
 github.com/ipfs/go-merkledag v0.2.0 h1:EAjIQCgZ6/DnOAlKY3+59j72FD9BsYtNaCRSmN0xIbU=
 github.com/ipfs/go-merkledag v0.2.0/go.mod h1:SQiXrtSts3KGNmgOzMICy5c0POOpUNQLvB3ClKnBAlk=
+github.com/ipfs/go-merkledag v0.2.3 h1:aMdkK9G1hEeNvn3VXfiEMLY0iJnbiQQUHnM0HFJREsE=
+github.com/ipfs/go-merkledag v0.2.3/go.mod h1:SQiXrtSts3KGNmgOzMICy5c0POOpUNQLvB3ClKnBAlk=
 github.com/ipfs/go-metrics-interface v0.0.1 h1:j+cpbjYvu4R8zbleSs36gvB7jR+wsL2fGD6n0jO4kdg=
 github.com/ipfs/go-metrics-interface v0.0.1/go.mod h1:6s6euYU4zowdslK0GKHmqaIZ3j/b/tL7HTWtJ4VPgWY=
 github.com/ipfs/go-metrics-prometheus v0.0.2 h1:9i2iljLg12S78OhC6UAiXi176xvQGiZaGVF1CUVdE+s=
@@ -320,8 +322,8 @@ github.com/ipfs/go-todocounter v0.0.1/go.mod h1:l5aErvQc8qKE2r7NDMjmq5UNAvuZy0rC
 github.com/ipfs/go-unixfs v0.0.4/go.mod h1:eIo/p9ADu/MFOuyxzwU+Th8D6xoxU//r590vUpWyfz8=
 github.com/ipfs/go-unixfs v0.0.8 h1:AHahQ+gdNZd9BhKVLf8XP1EWeKa78eTzYgCygp7N/Pg=
 github.com/ipfs/go-unixfs v0.0.8/go.mod h1:cK2vDJ7L4YnWB6oLefpVNesgx0x/zPTRVDw6B4Y+03U=
-github.com/ipfs/go-unixfs v0.2.0 h1:mfdI8rgsEifWfhLECrH2WphHvslNoPbdvlmsJ05Fu0M=
-github.com/ipfs/go-unixfs v0.2.0/go.mod h1:sy/j20FKUxdUYOl6GZb3wsQ593C2xk5r1i8U7W+5iio=
+github.com/ipfs/go-unixfs v0.2.1 h1:g51t9ODICFZ3F51FPivm8dE7NzYcdAQNUL9wGP5AYa0=
+github.com/ipfs/go-unixfs v0.2.1/go.mod h1:IwAAgul1UQIcNZzKPYZWOCijryFBeCV79cNubPzol+k=
 github.com/ipfs/go-verifcid v0.0.1 h1:m2HI7zIuR5TFyQ1b79Da5N9dnnCP1vcu2QqawmWlK2E=
 github.com/ipfs/go-verifcid v0.0.1/go.mod h1:5Hrva5KBeIog4A+UpqlaIU+DEstipcJYQQZc0g37pY0=
 github.com/ipfs/hang-fds v0.0.1 h1:KGAxiGtJPT3THVRNT6yxgpdFPeX4ZemUjENOt6NlOn4=

test/sharness/t0111-gateway-writeable.sh

@@ -54,17 +54,8 @@ test_expect_success "We can HTTP GET file just created" '
   test_cmp infile outfile
 '
 
-test_expect_success "HTTP PUT empty directory" '
-  URL="http://localhost:$port/ipfs/$HASH_EMPTY_DIR/" &&
-  echo "PUT $URL" &&
-  curl -svX PUT "$URL" 2>curl_putEmpty.out &&
-  cat curl_putEmpty.out &&
-  grep "Ipfs-Hash: $HASH_EMPTY_DIR" curl_putEmpty.out &&
-  grep "Location: /ipfs/$HASH_EMPTY_DIR" curl_putEmpty.out &&
-  grep "HTTP/1.1 201 Created" curl_putEmpty.out
-'
-
 test_expect_success "HTTP GET empty directory" '
+  URL="http://localhost:$port/ipfs/$HASH_EMPTY_DIR/" &&
   echo "GET $URL" &&
   curl -so outfile "$URL" 2>curl_getEmpty.out &&
   grep "Index of /ipfs/$HASH_EMPTY_DIR/" outfile
@@ -105,6 +96,24 @@ test_expect_success "We can HTTP GET file just updated" '
   test_cmp infile2 outfile2
 '
 
+test_expect_success "HTTP PUT to replace a directory" '
+  echo "$RANDOM" >infile3 &&
+  URL="http://localhost:$port/ipfs/$HASH/test" &&
+  echo "PUT $URL" &&
+  curl -svX PUT --data-binary @infile3 "$URL" 2>curl_putOverDirectory.out &&
+  grep "HTTP/1.1 201 Created" curl_putOverDirectory.out &&
+  LOCATION=$(grep Location curl_putOverDirectory.out) &&
+  HASH=$(expr "$LOCATION" : "< Location: /ipfs/\(.*\)/test")
+'
+
+test_expect_success "We can HTTP GET file just put over a directory" '
+  URL="http://localhost:$port/ipfs/$HASH/test" &&
+  echo "GET $URL" &&
+  curl -svo outfile3 "$URL" 2>curl_getOverDirectory.out &&
+  test_cmp infile3 outfile3
+'
+
+
 test_kill_ipfs_daemon
 
 test_done