Download a hardcoded file from ipfs

README.md

@@ -4,13 +4,17 @@ IPFS transport for apt
 
     sudo apt install python3 pip
     sudo pip3 install ipfsapi
+    sudo snap install ipfs
+    ipfs init
+    ipfs daemon &
 
 # Install
 
 Copy the ipfs file from this repo to the directory for apt transport methods:
 
     sudo wget --output-file /usr/lib/apt/methods/ipfs https://raw.githubusercontent.com/JaquerEspeis/apt-transport-ipfs/master/ipfs
+    sudo chmod +x /usr/lib/apt/methods/ipfs
 
 # Configure
 
-Add to your apt sources.list file an IPFS mirror. TODO set up a mirror.
+Add an IPFS mirror to your apt sources.list file. TODO set up a mirror.

ipfs

@@ -20,7 +20,12 @@
 # This is based on apt-transport-s3:
 # https://github.com/BashtonLtd/apt-transport-s3
 
+import hashlib
+import os
 import sys
+import tempfile
+
+import ipfsapi
 
 
 class IPFS_method():
@@ -33,15 +38,119 @@ class IPFS_method():
     def send_capabilities(self):
         self._send(100, {
             'Version': '1.1',
-            'Single-Instance': 'true',
-            'Send-Config': 'true'})
+            'Single-Instance': 'true'})
+
+    def send_status(self, headers):
+        self._send(102, headers)
+
+    def send_uri_start(self, headers):
+        self._send(200, headers)
+
+    def send_uri_done(self, headers):
+        self._send(201, headers)
+
+    def send_uri_failure(self, headers):
+        self._send(400, headers)
 
     def _send(self, code, headers):
         message = APTMessage(code, headers)
         sys.stdout.write(message.encode())
 
     def run(self):
-        pass
+        """Loop through requests on stdin"""
+        while True:
+            message = self._read_message()
+            if message is None:
+                return 0
+            if message['number'] == 600:
+                try:
+                    self.fetch(message)
+                except Exception as e:
+                    self.send_uri_failure({
+                        'URI': self.uri,
+                        'Message': e.__class__.__name__ + ": " + str(e)})
+            else:
+                return 100
+
+    def _read_message(self):
+        """Read an apt message.
+
+        Apt uses for communication with its methods the text protocol similar
+        to http. This function parses the protocol messages from stdin.
+
+        """
+        if self.__eof:
+            return None
+        result = {}
+        line = sys.stdin.readline()
+        while line == '\n':
+            line = sys.stdin.readline()
+        if not line:
+            self.__eof = True
+            return None
+        s = line.split(" ", 1)
+        result['number'] = int(s[0])
+        result['text'] = s[1].strip()
+        while not self.__eof:
+            line = sys.stdin.readline()
+            if not line:
+                self.__eof = True
+                return result
+            if line == '\n':
+                return result
+            (item, value) = line.split(":", 1)
+            if not result.get(item):
+                result[item] = []
+            result[item].append(value.strip())
+        return result
+
+    def fetch(self, message):
+        self.uri = message['URI'][0]
+        self.filename = message['Filename'][0]
+
+        self.send_status({'URI': self.uri, 'Message': 'Waiting for stats'})
+        ipfs = ipfsapi.connect('127.0.0.1', 5001)
+        inrelease = (
+            'QmabnVr8k4uFdwQ8dW2P3jEUxdVPF8FcAgc2i8q7T2ArMg/'
+            'dists/xenial/InRelease')
+        stat = ipfs.object_stat(inrelease)
+        self.send_uri_start({
+            'URI': self.uri,
+            # FIXME We can't get the real size without downloading the file.
+            # https://github.com/ipfs/go-ipfs/issues/2071
+            # --elopio - 20171203
+            'Size': stat['CumulativeSize']})
+
+        # XXX IPFS downloads the file to the current directory.
+        # --elopio - 20171203
+        tmp_dir = tempfile.gettempdir()
+        os.chdir(tmp_dir)
+        fetched_file_path = os.path.join(
+            tmp_dir, os.path.basename(inrelease))
+        cwd = os.getcwd()
+        try:
+            ipfs.get(inrelease)
+        finally:
+            os.chdir(cwd)
+        os.rename(fetched_file_path, self.filename)
+
+        hash_md5 = hashlib.md5()
+        hash_sha256 = hashlib.sha256()
+        hash_sha512 = hashlib.sha512()
+        with open(self.filename, 'rb') as fetched_file:
+            for chunk in iter(lambda: fetched_file.read(4096), b''):
+                hash_md5.update(chunk)
+                hash_sha256.update(chunk)
+                hash_sha512.update(chunk)
+
+        self.send_uri_done({
+            'URI': self.uri,
+            'Filename': self.filename,
+            'Size': os.stat(self.filename).st_size,
+            'MD5-Hash': hash_md5.hexdigest(),
+            'MD5Sum-Hash': hash_md5.hexdigest(),
+            'SHA256-Hash': hash_sha256.hexdigest(),
+            'SHA512-Hash': hash_sha512.hexdigest()})
 
 
 class APTMessage():