1 files changed, 191 insertions, 0 deletions
diff --git a/taskcluster/taskgraph/docker.py b/taskcluster/taskgraph/docker.py
new file mode 100644
index 0000000000..ffb85bb1b6
--- /dev/null
+++ b/taskcluster/taskgraph/docker.py
@@ -0,0 +1,191 @@
+# -*- coding: utf-8 -*-
+
+# This Source Code Form is subject to the terms of the Mozilla Public
+# License, v. 2.0. If a copy of the MPL was not distributed with this
+# file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+from __future__ import absolute_import, print_function, unicode_literals
+
+import json
+import os
+import six
+import tarfile
+from io import BytesIO
+
+from taskgraph.optimize.strategies import IndexSearch
+from taskgraph.util import docker
+from taskgraph.util.taskcluster import (
+    get_artifact_url,
+    get_session,
+)
+from taskgraph.generator import load_tasks_for_kind
+from . import GECKO
+
+
+def load_image_by_name(image_name, tag=None):
+    params = {"level": six.ensure_text(os.environ.get("MOZ_SCM_LEVEL", "3"))}
+    tasks = load_tasks_for_kind(params, "docker-image")
+    task = tasks["docker-image-{}".format(image_name)]
+    task_id = IndexSearch().should_replace_task(
+        task, {}, task.optimization.get("index-search", [])
+    )
+
+    if task_id in (True, False):
+        print(
+            "Could not find artifacts for a docker image "
+            "named `{image_name}`. Local commits and other changes "
+            "in your checkout may cause this error. Try "
+            "updating to a fresh checkout of mozilla-central "
+            "to download image.".format(image_name=image_name)
+        )
+        return False
+
+    return load_image_by_task_id(task_id, tag)
+
+
+def load_image_by_task_id(task_id, tag=None):
+    artifact_url = get_artifact_url(task_id, "public/image.tar.zst")
+    result = load_image(artifact_url, tag)
+    print("Found docker image: {}:{}".format(result["image"], result["tag"]))
+    if tag:
+        print("Re-tagged as: {}".format(tag))
+    else:
+        tag = "{}:{}".format(result["image"], result["tag"])
+    print("Try: docker run -ti --rm {} bash".format(tag))
+    return True
+
+
+def build_context(name, outputFile, args=None):
+    """Build a context.tar for image with specified name."""
+    if not name:
+        raise ValueError("must provide a Docker image name")
+    if not outputFile:
+        raise ValueError("must provide a outputFile")
+
+    image_dir = docker.image_path(name)
+    if not os.path.isdir(image_dir):
+        raise Exception("image directory does not exist: %s" % image_dir)
+
+    docker.create_context_tar(GECKO, image_dir, outputFile, image_name=name, args=args)
+
+
+def build_image(name, tag, args=None):
+    """Build a Docker image of specified name.
+
+    Output from image building process will be printed to stdout.
+    """
+    if not name:
+        raise ValueError("must provide a Docker image name")
+
+    image_dir = docker.image_path(name)
+    if not os.path.isdir(image_dir):
+        raise Exception("image directory does not exist: %s" % image_dir)
+
+    tag = tag or docker.docker_image(name, by_tag=True)
+
+    buf = BytesIO()
+    docker.stream_context_tar(GECKO, image_dir, buf, name, args)
+    docker.post_to_docker(buf.getvalue(), "/build", nocache=1, t=tag)
+
+    print("Successfully built %s and tagged with %s" % (name, tag))
+
+    if tag.endswith(":latest"):
+        print("*" * 50)
+        print("WARNING: no VERSION file found in image directory.")
+        print("Image is not suitable for deploying/pushing.")
+        print("Create an image suitable for deploying/pushing by creating")
+        print("a VERSION file in the image directory.")
+        print("*" * 50)
+
+
+def load_image(url, imageName=None, imageTag=None):
+    """
+    Load docker image from URL as imageName:tag, if no imageName or tag is given
+    it will use whatever is inside the zstd compressed tarball.
+
+    Returns an object with properties 'image', 'tag' and 'layer'.
+    """
+    import zstandard as zstd
+
+    # If imageName is given and we don't have an imageTag
+    # we parse out the imageTag from imageName, or default it to 'latest'
+    # if no imageName and no imageTag is given, 'repositories' won't be rewritten
+    if imageName and not imageTag:
+        if ":" in imageName:
+            imageName, imageTag = imageName.split(":", 1)
+        else:
+            imageTag = "latest"
+
+    info = {}
+
+    def download_and_modify_image():
+        # This function downloads and edits the downloaded tar file on the fly.
+        # It emits chunked buffers of the editted tar file, as a generator.
+        print("Downloading from {}".format(url))
+        # get_session() gets us a requests.Session set to retry several times.
+        req = get_session().get(url, stream=True)
+        req.raise_for_status()
+
+        with zstd.ZstdDecompressor().stream_reader(req.raw) as ifh:
+
+            tarin = tarfile.open(
+                mode="r|",
+                fileobj=ifh,
+                bufsize=zstd.DECOMPRESSION_RECOMMENDED_OUTPUT_SIZE,
+            )
+
+            # Stream through each member of the downloaded tar file individually.
+            for member in tarin:
+                # Non-file members only need a tar header. Emit one.
+                if not member.isfile():
+                    yield member.tobuf(tarfile.GNU_FORMAT)
+                    continue
+
+                # Open stream reader for the member
+                reader = tarin.extractfile(member)
+
+                # If member is `repositories`, we parse and possibly rewrite the
+                # image tags.
+                if member.name == "repositories":
+                    # Read and parse repositories
+                    repos = json.loads(reader.read())
+                    reader.close()
+
+                    # If there is more than one image or tag, we can't handle it
+                    # here.
+                    if len(repos.keys()) > 1:
+                        raise Exception("file contains more than one image")
+                    info["image"] = image = list(repos.keys())[0]
+                    if len(repos[image].keys()) > 1:
+                        raise Exception("file contains more than one tag")
+                    info["tag"] = tag = list(repos[image].keys())[0]
+                    info["layer"] = layer = repos[image][tag]
+
+                    # Rewrite the repositories file
+                    data = json.dumps({imageName or image: {imageTag or tag: layer}})
+                    reader = BytesIO(data.encode("utf-8"))
+                    member.size = len(data)
+
+                # Emit the tar header for this member.
+                yield member.tobuf(tarfile.GNU_FORMAT)
+                # Then emit its content.
+                remaining = member.size
+                while remaining:
+                    length = min(remaining, zstd.DECOMPRESSION_RECOMMENDED_OUTPUT_SIZE)
+                    buf = reader.read(length)
+                    remaining -= len(buf)
+                    yield buf
+                # Pad to fill a 512 bytes block, per tar format.
+                remainder = member.size % 512
+                if remainder:
+                    yield ("\0" * (512 - remainder)).encode("utf-8")
+
+                reader.close()
+
+    docker.post_to_docker(download_and_modify_image(), "/images/load", quiet=0)
+
+    # Check that we found a repositories file
+    if not info.get("image") or not info.get("tag") or not info.get("layer"):
+        raise Exception("No repositories file found!")
+
+    return info