TUN-6054: Create and upload deb packages to R2

   This PR does the following:
   1. Creates packages.gz, signed InRelease files for debs in
      built_artifacts for configured debian releases.
   2. Uploads them to Cloudflare R2.
   3. Adds a Workers KV entry that talks about where these assets are
      uploaded.

Author: sudarshan-reddy

release_pkgs.py

@@ -0,0 +1,229 @@
+"""
+    This is a utility for creating deb and rpm packages, signing them 
+    and uploading them to a storage and adding metadata to workers KV.
+
+    It has two over-arching responsiblities:
+    1. Create deb and yum repositories from .deb and .rpm files. 
+       This is also responsible for signing the packages and generally preparing 
+       them to be in an uploadable state.
+    2. Upload these packages to a storage and add metadata cross reference 
+       for these to be accessed.
+"""
+import requests
+import subprocess
+import os
+import io
+import shutil
+import logging
+from hashlib import sha256
+
+import boto3
+from botocore.client import Config
+from botocore.exceptions import ClientError
+
+BASE_KV_URL = 'https://api.cloudflare.com/client/v4/accounts/'
+# The front facing R2 URL to access assets from.
+R2_ASSET_URL = 'https://demo-r2-worker.cloudflare-tunnel.workers.dev/'
+
+class PkgUploader:
+    def __init__(self, kv_api_token, namespace, account_id, bucket_name, client_id, client_secret):
+        self.kv_api_token = kv_api_token
+        self.namespace = namespace
+        self.account_id = account_id
+        self.bucket_name = bucket_name
+        self.client_id = client_id
+        self.client_secret = client_secret
+
+    def send_to_kv(self, key, value):
+        headers = {
+            "Content-Type": "application/json",
+            "Authorization": "Bearer " + self.kv_api_token,
+        }
+
+        kv_url = f"{BASE_KV_URL}{self.account_id}/storage/kv/namespaces/{self.namespace}/values/{key}"
+        response = requests.put(
+                kv_url,
+                headers=headers,
+                data=value
+        )
+    
+        if response.status_code != 200:
+            jsonResponse = response.json()
+            errors = jsonResponse["errors"]
+            if len(errors) > 0:
+                raise Exception("failed to send to workers kv: {0}", errors[0])
+            else:
+                raise Exception("recieved error code: {0}", response.status_code)
+    
+    
+    def send_pkg_info(self, binary, flavor, asset_name, arch, uploaded_package_location):
+        key = f"pkg_{binary}_{flavor}_{arch}_{asset_name}"
+        print(f"writing key:{key} , value: {uploaded_package_location}")
+        self.send_to_kv(key, uploaded_package_location)
+    
+    
+    def upload_pkg_to_r2(self, filename, upload_file_path):
+        endpoint_url = f"https://{self.account_id}.r2.cloudflarestorage.com"
+        token_secret_hash = sha256(self.client_secret.encode()).hexdigest()
+         
+        config = Config(
+            s3={
+                "addressing_style": "path",
+            }
+        )
+         
+        r2 = boto3.client(
+            "s3",
+            endpoint_url=endpoint_url,
+            aws_access_key_id=self.client_id,
+            aws_secret_access_key=token_secret_hash,
+            config=config,
+        )
+
+        print(f"uploading asset: {filename} to {upload_file_path}...")
+        try:
+            r2.upload_file(filename, self.bucket_name, upload_file_path)
+        except ClientError as e:
+            raise e
+
+                  
+class PkgCreator:
+    """
+        The distribution conf is what dictates to reprepro, the debian packaging building
+        and signing tool we use, what distros to support, what GPG key to use for signing
+        and what to call the debian binary etc. This function creates it "./conf/distributions".
+
+        origin - name of your package (String)
+        label - label of your package (could be same as the name) (String)
+        flavor - flavor you want this to be distributed for (List of Strings)
+        components - could be a channel like main/stable/beta
+        archs - Architecture (List of Strings)
+        description - (String)
+        gpg_key_id - gpg key id of what you want to use to sign the packages.(String) 
+    """
+    def create_distribution_conf(self, 
+            file_path,
+            origin,
+            label,
+            flavors,
+            archs,
+            components, 
+            description,
+            gpg_key_id ):
+        with open(file_path, "w") as distributions_file:
+            for flavor in flavors:
+                distributions_file.write(f"Origin: {origin}\n")
+                distributions_file.write(f"Label: {label}\n")
+                distributions_file.write(f"Codename: {flavor}\n")
+                archs_list = " ".join(archs)
+                distributions_file.write(f"Architectures: {archs_list}\n")
+                distributions_file.write(f"Components: {components}\n")
+                distributions_file.write(f"Description: {description} - {flavor}\n")
+                distributions_file.write(f"SignWith: {gpg_key_id}\n")
+                distributions_file.write("\n")
+        return distributions_file
+
+    """
+        Uses the reprepro tool to generate packages, sign them and create the InRelease as specified
+        by the distribution_conf file. 
+
+        This function creates three folders db, pool and dist. 
+        db and pool contain information and metadata about builds. We can ignore these.
+        dist: contains all the pkgs and signed releases that are necessary for an apt download.
+    """
+    def create_deb_pkgs(self, flavor, deb_file):
+        self._clean_build_resources()
+        subprocess.call(("reprepro", "includedeb", flavor, deb_file))
+
+    """
+        This is mostly useful to clear previously built db, dist and pool resources.
+    """
+    def _clean_build_resources(self):
+        subprocess.call(("reprepro", "clearvanished"))
+
+def upload_from_directories(pkg_uploader, directory, arch, release):
+     for root, _ , files in os.walk(directory):
+        for file in files:
+            root_elements = root.split("/")
+            upload_file_name = os.path.join(root, arch, release, file)
+            flavor_prefix = root_elements[1]
+            if root_elements[0] == "pool":
+                upload_file_name = os.path.join(root, file)
+                flavor_prefix = "deb"
+            filename = os.path.join(root,file)
+            try: 
+                pkg_uploader.upload_pkg_to_r2(filename, upload_file_name)
+            except ClientError as e:
+                logging.error(e)
+                return 
+
+            # save to workers kv in the following formats
+            # Example:
+            # key : pkg_cloudflared_bullseye_InRelease,
+            # value: https://r2.cloudflarestorage.com/dists/bullseye/amd64/2022_3_4/InRelease
+            r2_asset_url = f"{R2_ASSET_URL}{upload_file_name}"
+            pkg_uploader.send_pkg_info("cloudflared", flavor_prefix,  upload_file_name, arch, r2_asset_url)
+
+            # TODO https://jira.cfops.it/browse/TUN-6163: Add a key for latest version.
+
+""" 
+    1. looks into a built_artifacts folder for cloudflared debs
+    2. creates Packages.gz, InRelease (signed) files
+    3. uploads them to Cloudflare R2 and
+    4. adds a Workers KV reference
+
+    pkg_creator, pkg_uploader: are instantiations of the two classes above.
+
+    gpg_key_id: is an id indicating the key the package should be signed with. The public key of this id will be 
+    uploaded to R2 so it can be presented to apt downloaders.
+
+    release_version: is the cloudflared release version.
+"""
+def create_deb_packaging(pkg_creator, pkg_uploader, flavors, gpg_key_id, binary_name, arch, package_component, release_version):
+    # set configuration for package creation.
+    print(f"initialising configuration for {binary_name} , {arch}")
+    pkg_creator.create_distribution_conf(
+    "./conf/distributions",
+    binary_name,
+    binary_name,
+    flavors,
+    [arch],
+    package_component,
+    f"apt repository for {binary_name}",
+    gpg_key_id)
+
+    # create deb pkgs
+    for flavor in flavors:
+        print(f"creating deb pkgs for {flavor} and {arch}...")
+        pkg_creator.create_deb_pkgs(flavor, f"./built_artifacts/cloudflared-linux-{arch}.deb")
+
+    print("uploading to r2...")
+    upload_from_directories(pkg_uploader, "dists", arch, release_version)
+    upload_from_directories(pkg_uploader, "pool", arch, release_version)
+
+    print("cleaning up directories...")
+    shutil.rmtree("./dists")
+    shutil.rmtree("./pool")
+    shutil.rmtree("./db")
+
+#TODO: https://jira.cfops.it/browse/TUN-6146 will extract this into it's own command line script.
+if __name__ == "__main__":
+    # initialise pkg creator
+    pkg_creator = PkgCreator()
+   
+    # initialise pkg uploader
+    bucket_name = os.getenv('R2_BUCKET_NAME')
+    client_id = os.getenv('R2_CLIENT_ID')
+    client_secret = os.getenv('R2_CLIENT_SECRET')
+    tunnel_account_id = '5ab4e9dfbd435d24068829fda0077963'
+    kv_namespace = os.getenv('KV_NAMESPACE')
+    kv_api_token = os.getenv('KV_API_TOKEN')
+    release_version = os.getenv('RELEASE_VERSION')
+    gpg_key_id = os.getenv('GPG_KEY_ID')
+
+    pkg_uploader = PkgUploader(kv_api_token, kv_namespace, tunnel_account_id, bucket_name, client_id, client_secret)
+
+    archs = ["amd64", "386", "arm64"]
+    flavors = ["bullseye", "buster", "bionic"]
+    for arch in archs:
+        create_deb_packaging(pkg_creator, pkg_uploader, flavors, gpg_key_id, "cloudflared", arch, "main", release_version)