feat(gateway): X-Ipfs-Path, Etag, Cache-Control, Suborigin

Return the same headers as HTTP Gateway exposed by go-ipfs:
- X-Ipfs-Path: requested IPFS Path of returned resource
- Etag: multihash of returned payload
- Cache-Control: disable cache for directory listings and errors,
  enable heavy caching for immutable assets from /ipfs/ namespace
- Suborigin: use root CID in base32 and literal prefix to conform
  to current suborigin spec

License: MIT
Signed-off-by: Marcin Rataj <lidel@lidel.org>

src/http/gateway/resources/gateway.js

@@ -41,6 +41,7 @@ module.exports = {
       ref: `/ipfs/${request.params.cid}`
     })
   },
+
   handler: (request, reply) => {
     const ref = request.pre.args.ref
     const ipfs = request.server.app.ipfs
@@ -120,6 +121,15 @@ module.exports = {
 
         let response = reply(stream2).hold()
 
+        // Etag maps directly to an identifier for a specific version of a resource
+        // TODO: change to .cid.toBaseEncodedString() after switch to new js-ipfs-http-response
+        response.header('Etag', `"${data.multihash}"`)
+
+        // Set headers specific to the immutable namespace
+        if (ref.startsWith('/ipfs/')) {
+          response.header('Cache-Control', 'public, max-age=29030400, immutable')
+        }
+
         pull(
           toPull.source(stream),
           pull.through((chunk) => {
@@ -148,5 +158,22 @@ module.exports = {
         )
       }
     })
+  },
+
+  afterHandler: (request, reply) => {
+    const response = request.response
+    if (response.statusCode === 200) {
+      const ref = request.pre.args.ref
+      response.header('X-Ipfs-Path', ref)
+      if (ref.startsWith('/ipfs/')) {
+        const rootCid = ref.split('/')[2]
+        const CID = request.server.app.ipfs.types.CID
+        const ipfsOrigin = new CID(rootCid).toV1().toBaseEncodedString('base32')
+        response.header('Suborigin', 'ipfs000' + ipfsOrigin)
+      }
+      // TODO: we don't have case-insensitive solution for /ipns/ yet (https://github.com/ipfs/go-ipfs/issues/5287)
+    }
+    reply.continue()
   }
+
 }

src/http/gateway/routes/gateway.js

@@ -12,7 +12,10 @@ module.exports = (server) => {
       pre: [
         { method: resources.gateway.checkCID, assign: 'args' }
       ],
-      handler: resources.gateway.handler
+      handler: resources.gateway.handler,
+      ext: {
+        onPostHandler: { method: resources.gateway.afterHandler }
+      }
     }
   })
 }

test/gateway/index.js

@@ -93,7 +93,7 @@ describe('HTTP Gateway', function () {
       (cb) => {
         const expectedMultihash = 'QmT78zSuBmuS4z925WZfrqQ1qHaJ56DQaTfyMUF7F8ff5o'
 
-        http.api.node.files.add(Buffer.from('hello world' + '\n'), (err, res) => {
+        http.api.node.files.add(Buffer.from('hello world' + '\n'), {cidVersion: 0}, (err, res) => {
           expect(err).to.not.exist()
           const file = res[0]
           expect(file.path).to.equal(expectedMultihash)
@@ -144,6 +144,10 @@ describe('HTTP Gateway', function () {
     }, (res) => {
       expect(res.statusCode).to.equal(400)
       expect(res.result.Message).to.be.a('string')
+      expect(res.headers['cache-control']).to.equal('no-cache')
+      expect(res.headers['etag']).to.equal(undefined)
+      expect(res.headers['x-ipfs-path']).to.equal(undefined)
+      expect(res.headers['suborigin']).to.equal(undefined)
       done()
     })
   })
@@ -155,21 +159,49 @@ describe('HTTP Gateway', function () {
     }, (res) => {
       expect(res.statusCode).to.equal(400)
       expect(res.result.Message).to.be.a('string')
+      expect(res.headers['cache-control']).to.equal('no-cache')
+      expect(res.headers['etag']).to.equal(undefined)
+      expect(res.headers['x-ipfs-path']).to.equal(undefined)
+      expect(res.headers['suborigin']).to.equal(undefined)
       done()
     })
   })
 
-  it('valid hash', (done) => {
+  it('valid CIDv0', (done) => {
     gateway.inject({
       method: 'GET',
       url: '/ipfs/QmT78zSuBmuS4z925WZfrqQ1qHaJ56DQaTfyMUF7F8ff5o'
     }, (res) => {
       expect(res.statusCode).to.equal(200)
       expect(res.rawPayload).to.eql(Buffer.from('hello world' + '\n'))
       expect(res.payload).to.equal('hello world' + '\n')
+      expect(res.headers['cache-control']).to.equal('public, max-age=29030400, immutable')
+      expect(res.headers['etag']).to.equal('"QmT78zSuBmuS4z925WZfrqQ1qHaJ56DQaTfyMUF7F8ff5o"')
+      expect(res.headers['x-ipfs-path']).to.equal('/ipfs/QmT78zSuBmuS4z925WZfrqQ1qHaJ56DQaTfyMUF7F8ff5o')
+      expect(res.headers['suborigin']).to.equal('ipfs000bafybeicg2rebjoofv4kbyovkw7af3rpiitvnl6i7ckcywaq6xjcxnc2mby')
+
+      done()
+    })
+  })
+
+  /* TODO when support for CIDv1 lands
+  it('valid CIDv1', (done) => {
+    gateway.inject({
+      method: 'GET',
+      url: '/ipfs/TO-DO'
+    }, (res) => {
+      expect(res.statusCode).to.equal(200)
+      expect(res.rawPayload).to.eql(Buffer.from('hello world' + '\n'))
+      expect(res.payload).to.equal('hello world' + '\n')
+      expect(res.headers['etag']).to.equal(TO-DO)
+      expect(res.headers['x-ipfs-path']).to.equal(TO-DO)
+      expect(res.headers['suborigin']).to.equal(TO-DO)
+      expect(res.headers['cache-control']).to.equal('public, max-age=29030400, immutable')
+
       done()
     })
   })
+  */
 
   it('stream a large file', (done) => {
     let bigFileHash = 'Qme79tX2bViL26vNjPsF3DP1R9rMKMvnPYJiKTTKPrXJjq'
@@ -193,6 +225,10 @@ describe('HTTP Gateway', function () {
     }, (res) => {
       expect(res.statusCode).to.equal(200)
       expect(res.headers['content-type']).to.equal('image/jpeg')
+      expect(res.headers['x-ipfs-path']).to.equal('/ipfs/' + kitty)
+      expect(res.headers['cache-control']).to.equal('public, max-age=29030400, immutable')
+      expect(res.headers['etag']).to.equal('"Qmd286K6pohQcTKYqnS1YhWrCiS4gz7Xi34sdwMe9USZ7u"')
+      expect(res.headers['suborigin']).to.equal('ipfs000bafybeidsg6t7ici2osxjkukisd5inixiunqdpq2q5jy4a2ruzdf6ewsqk4')
 
       let fileSignature = fileType(res.rawPayload)
       expect(fileSignature.mime).to.equal('image/jpeg')
@@ -239,6 +275,10 @@ describe('HTTP Gateway', function () {
     }, (res) => {
       expect(res.statusCode).to.equal(200)
       expect(res.headers['content-type']).to.equal('text/html; charset=utf-8')
+      expect(res.headers['x-ipfs-path']).to.equal('/ipfs/' + dir)
+      expect(res.headers['cache-control']).to.equal('no-cache')
+      expect(res.headers['etag']).to.equal(undefined)
+      expect(res.headers['suborigin']).to.equal('ipfs000bafybeidsg6t7ici2osxjkukisd5inixiunqdpq2q5jy4a2ruzdf6ewsqk4')
 
       // check if the cat picture is in the payload as a way to check
       // if this is an index of this directory
@@ -256,6 +296,11 @@ describe('HTTP Gateway', function () {
       url: '/ipfs/' + dir
     }, (res) => {
       expect(res.statusCode).to.equal(200)
+      expect(res.headers['content-type']).to.equal('text/html; charset=utf-8')
+      expect(res.headers['x-ipfs-path']).to.equal('/ipfs/' + dir)
+      expect(res.headers['cache-control']).to.equal('public, max-age=29030400, immutable')
+      expect(res.headers['etag']).to.equal('"Qma6665X5k3zti8nKy7gmXK2BndNDSkgmANpV6k3FUjUeg"')
+      expect(res.headers['suborigin']).to.equal('ipfs000bafybeigccfheqv7upr4k64bkg5b5wiwelunyn2l2rbirmm43m34lcpuqqe')
       expect(res.rawPayload).to.deep.equal(directoryContent['index.html'])
       done()
     })
@@ -269,6 +314,11 @@ describe('HTTP Gateway', function () {
       url: '/ipfs/' + dir
     }, (res) => {
       expect(res.statusCode).to.equal(200)
+      expect(res.headers['content-type']).to.equal('text/html; charset=utf-8')
+      expect(res.headers['x-ipfs-path']).to.equal('/ipfs/' + dir)
+      expect(res.headers['cache-control']).to.equal('public, max-age=29030400, immutable')
+      expect(res.headers['etag']).to.equal('"QmUBKGqJWiJYMrNed4bKsbo1nGYGmY418WCc2HgcwRvmHc"')
+      expect(res.headers['suborigin']).to.equal('ipfs000bafybeigccfheqv7upr4k64bkg5b5wiwelunyn2l2rbirmm43m34lcpuqqe')
       expect(res.rawPayload).to.deep.equal(directoryContent['nested-folder/nested.html'])
       done()
     })
@@ -283,6 +333,7 @@ describe('HTTP Gateway', function () {
     }, (res) => {
       expect(res.statusCode).to.equal(301)
       expect(res.headers['location']).to.equal('/ipfs/QmW2WQi7j6c7UgJTarActp7tDNikE4B2qXtFCfLPdsgaTQ/')
+      expect(res.headers['x-ipfs-path']).to.equal(undefined)
       done()
     })
   })
@@ -296,6 +347,7 @@ describe('HTTP Gateway', function () {
     }, (res) => {
       expect(res.statusCode).to.equal(302)
       expect(res.headers['location']).to.equal('/ipfs/QmbQD7EMEL1zeebwBsWEfA3ndgSS6F7S6iTuwuqasPgVRi/index.html')
+      expect(res.headers['x-ipfs-path']).to.equal(undefined)
       done()
     })
   })