Merge ~pappacena/launchpad:fork-button into launchpad:master

[Thiago F. Pappacena]

Adding UI to allow forking a git repository

[Thiago F. Pappacena (pappacena)]

This branch depends on https://code.launchpad.net/~pappacena/launchpad/+git/launchpad/+merge/387146

d87633a... by Thiago F. Pappacena on 2020-07-15

Merge branch 'git-fork-backend' into fork-button

4e5bb5e... by Thiago F. Pappacena on 2020-07-15

Fixing IGitRepositorySet.fork call

b90fd8f... by Thiago F. Pappacena on 2020-07-16

Merge branch 'git-fork-backend' into fork-button

cf5ebb0... by Thiago F. Pappacena on 2020-07-17

Small fix on fork URL for projects

4d594ef... by Thiago F. Pappacena on 2020-07-17

Merge branch 'git-fork-backend' into fork-button

18f4666... by Thiago F. Pappacena on 2020-07-17

Show fork button only for views that explicitly declare it

62081da... by Thiago F. Pappacena on 2020-07-18

Merge branch 'git-fork-backend' into fork-button

188ef86... by Thiago F. Pappacena on 2020-07-24

Adding feature flag to enable / disable fork button

[Colin Watson (cjwatson)]

This looks essentially OK aside from a few corrections described below, but I'd like to see at least a screenshot or two of what this looks like in practice as well, please.

review: Needs Information

e657c03... by Thiago F. Pappacena on 2020-09-22

Merge branch 'git-fork-backend' into fork-button

[Thiago F. Pappacena (pappacena)]

Some screenshots, while I work on the diff comments:

The fork button itself: https://monosnap.com/file/CaNNw6uDQH5crkfzy9qQ2rcZ12Side
New repository's owner selection: https://monosnap.com/file/VKIAxNQ5Cv01FVgmrrI5WS2QOYKuan
Owners selector open: https://monosnap.com/file/fVSk2vMeCyYkwf10nM27M6zqNHyZ7S

52c0f04... by Thiago F. Pappacena on 2020-09-22

Refactoring

bc92b17... by Thiago F. Pappacena on 2020-09-22

Fixing tests

[Colin Watson (cjwatson)]

OK, in that case I think all the comments I have are covered by my previous set of inline comments, thanks. (Ultimately we'll probably want the Fork link to be a JS link that pops up an owner picker and then lets you start the fork process without loading a new page, but I'm not expecting that in this round.)

review: Needs Fixing

52ffd87... by Thiago F. Pappacena on 2020-09-22

Rearrange fork link position

[Thiago F. Pappacena (pappacena)]

Pushed the requested changes.

I have also changed slightly the button text, to make it fit better in the text when user can/cannot push to the original repository:

- When user can push directly (and there is no push URL hint): https://monosnap.com/file/LK24hWnrv9tIiBe6sqx5Me1mb9okq3
- When user cannot push directly (and there is the push URL hint): https://monosnap.com/file/3r4y9L7wnHKFFLVAqYTZvOsZVNPDjg

I would like some opinion on the text before landing this.

[Colin Watson (cjwatson)]

This looks pretty good, thanks; just some small suggestions. Also note that the supporting turnip changes need to be on production (not just master and/or qastaging) before landing this.

review: Approve

68e062a... by Thiago F. Pappacena on 2020-09-22

Linting the code and changing fork message

[Thiago F. Pappacena (pappacena)]

Pushed the changes

[Thiago F. Pappacena (pappacena)]

The corresponding changes on Turnip reached production already.

Worst case scenario, we still have the feature flag to hit the fork button.

Landing this MP.

diff --git a/lib/lp/code/browser/configure.zcml b/lib/lp/code/browser/configure.zcml
index 499a86a..e7943c0 100644
--- a/lib/lp/code/browser/configure.zcml
+++ b/lib/lp/code/browser/configure.zcml
@@ -1,4 +1,4 @@
-<!-- Copyright 2009-2018 Canonical Ltd.  This software is licensed under the
+<!-- Copyright 2009-2020 Canonical Ltd.  This software is licensed under the
      GNU Affero General Public License version 3 (see the file LICENSE).
 -->
 
@@ -885,6 +885,12 @@
         template="../templates/gitrepository-rescan.pt"/>
     <browser:page
         for="lp.code.interfaces.gitrepository.IGitRepository"
+        class="lp.code.browser.gitrepository.GitRepositoryForkView"
+        permission="launchpad.View"
+        name="+fork"
+        template="../templates/gitrepository-fork.pt"/>
+    <browser:page
+        for="lp.code.interfaces.gitrepository.IGitRepository"
         class="lp.code.browser.codeimport.CodeImportEditView"
         permission="launchpad.Edit"
         name="+edit-import"
diff --git a/lib/lp/code/browser/gitrepository.py b/lib/lp/code/browser/gitrepository.py
index 76b9f7d..2552ffb 100644
--- a/lib/lp/code/browser/gitrepository.py
+++ b/lib/lp/code/browser/gitrepository.py
@@ -40,6 +40,7 @@ from six.moves.urllib_parse import (
 from zope.component import getUtility
 from zope.event import notify
 from zope.formlib import form
+from zope.formlib.form import FormFields
 from zope.formlib.textwidgets import IntWidget
 from zope.formlib.widget import CustomWidgetFactory
 from zope.interface import (
@@ -58,6 +59,7 @@ from zope.schema.vocabulary import (
     SimpleTerm,
     SimpleVocabulary,
     )
+from zope.security.interfaces import Unauthorized
 
 from lp import _
 from lp.app.browser.informationtype import InformationTypePortletMixin
@@ -103,6 +105,7 @@ from lp.code.interfaces.gitref import IGitRefBatchNavigator
 from lp.code.interfaces.gitrepository import (
     ContributorGitIdentity,
     IGitRepository,
+    IGitRepositorySet,
     )
 from lp.code.vocabularies.gitrule import GitPermissionsVocabulary
 from lp.registry.interfaces.person import (
@@ -141,6 +144,9 @@ from lp.services.webhooks.browser import WebhookTargetNavigationMixin
 from lp.snappy.browser.hassnaps import HasSnapsViewMixin
 
 
+GIT_REPOSITORY_FORK_ENABLED = 'gitrepository.fork.enabled'
+
+
 @implementer(ICanonicalUrlData)
 class GitRepositoryURL:
     """Git repository URL creation rules."""
@@ -479,6 +485,62 @@ class GitRepositoryView(InformationTypePortletMixin, LaunchpadView,
             return "This repository is being created."
         return None
 
+    @property
+    def allow_fork(self):
+        if not getFeatureFlag(GIT_REPOSITORY_FORK_ENABLED):
+            return False
+        # User cannot fork repositories they already own (note that forking a
+        # repository owned by a team the user is in is still fine).
+        if self.context.owner == self.user:
+            return False
+        return self.context.namespace.supports_repository_forking
+
+    @property
+    def fork_url(self):
+        return canonical_url(self.context, view_name='+fork')
+
+
+class GitRepositoryForkView(LaunchpadEditFormView):
+
+    schema = Interface
+
+    field_names = []
+
+    def initialize(self):
+        if not getFeatureFlag(GIT_REPOSITORY_FORK_ENABLED):
+            raise Unauthorized()
+        super(GitRepositoryForkView, self).initialize()
+
+    def setUpFields(self):
+        super(GitRepositoryForkView, self).setUpFields()
+        owner_field = Choice(
+            vocabulary='AllUserTeamsParticipationPlusSelf',
+            title=u'Fork to the following owner', required=True,
+            __name__=u'owner')
+        self.form_fields += FormFields(owner_field)
+
+    @property
+    def initial_values(self):
+        return {'owner': self.user}
+
+    def validate(self, data):
+        new_owner = data.get("owner")
+        if not new_owner or not self.user.inTeam(new_owner):
+            self.setFieldError(
+                "owner",
+                "You should select a valid user to fork the repository.")
+
+    @action('Fork it', name='fork')
+    def fork(self, action, data):
+        forked = getUtility(IGitRepositorySet).fork(
+            self.context, self.user, data.get("owner"))
+        self.request.response.addNotification("Repository forked.")
+        self.next_url = canonical_url(forked)
+
+    @property
+    def cancel_url(self):
+        return canonical_url(self.context)
+
 
 class GitRepositoryRescanView(LaunchpadEditFormView):
 
diff --git a/lib/lp/code/browser/tests/test_gitrepository.py b/lib/lp/code/browser/tests/test_gitrepository.py
index d3211ba..912965d 100644
--- a/lib/lp/code/browser/tests/test_gitrepository.py
+++ b/lib/lp/code/browser/tests/test_gitrepository.py
@@ -18,6 +18,10 @@ from textwrap import dedent
 from fixtures import FakeLogger
 import pytz
 import soupmatchers
+from soupmatchers import (
+    Tag,
+    HTMLContains,
+    )
 from storm.store import Store
 from testtools.matchers import (
     AfterPreprocessing,
@@ -28,6 +32,7 @@ from testtools.matchers import (
     MatchesListwise,
     MatchesSetwise,
     MatchesStructure,
+    Not,
     )
 import transaction
 from zope.component import getUtility
@@ -40,16 +45,21 @@ from lp.app.enums import InformationType
 from lp.app.errors import UnexpectedFormData
 from lp.app.interfaces.launchpad import ILaunchpadCelebrities
 from lp.app.interfaces.services import IService
-from lp.code.browser.gitrepository import encode_form_field_id
+from lp.code.browser.gitrepository import (
+    encode_form_field_id,
+    GIT_REPOSITORY_FORK_ENABLED,
+    )
 from lp.code.enums import (
     BranchMergeProposalStatus,
     CodeReviewVote,
     GitActivityType,
     GitGranteeType,
+    GitListingSort,
     GitPermissionType,
     GitRepositoryStatus,
     GitRepositoryType,
     )
+from lp.code.interfaces.gitcollection import IGitCollection
 from lp.code.interfaces.gitrepository import IGitRepositorySet
 from lp.code.interfaces.revision import IRevisionSet
 from lp.code.model.gitjob import GitRefScanJob
@@ -131,6 +141,10 @@ class TestGitRepositoryView(BrowserTestCase):
 
     layer = LaunchpadFunctionalLayer
 
+    def setUp(self):
+        super(TestGitRepositoryView, self).setUp()
+        self.useFixture(FeatureFixture({GIT_REPOSITORY_FORK_ENABLED: 'on'}))
+
     def test_clone_instructions(self):
         repository = self.factory.makeGitRepository()
         username = repository.owner.name
@@ -538,7 +552,7 @@ class TestGitRepositoryView(BrowserTestCase):
             repository, "+repository-portlet-subscriber-content")
         with StormStatementRecorder() as recorder:
             view.render()
-        self.assertThat(recorder, HasQueryCount(Equals(6)))
+        self.assertThat(recorder, HasQueryCount(Equals(7)))
 
     def test_show_rescan_link(self):
         repository = self.factory.makeGitRepository()
@@ -573,6 +587,65 @@ class TestGitRepositoryView(BrowserTestCase):
         result = view.show_rescan_link
         self.assertTrue(result)
 
+    def assertContainsForkLink(self, browser, repository, text):
+        """Asserts that browser contains the fork link with the given text"""
+        with admin_logged_in():
+            url = canonical_url(repository, view_name='+fork')
+        fork_link = Tag(
+            "fork link", "a",
+            text=re.compile(re.escape(text)),
+            attrs={"class": "sprite add", "href": url})
+        self.assertThat(browser.contents, HTMLContains(fork_link))
+
+    def assertDoesntContainForkLink(self, browser, repository, texts):
+        """Asserts that there is no fork button with any of the given texts."""
+        with admin_logged_in():
+            url = canonical_url(repository, view_name='+fork')
+        for text in texts:
+            fork_link = Tag(
+                "fork link", "a",
+                text=re.compile(re.escape(text)),
+                attrs={"class": "sprite add", "href": url})
+            self.assertThat(browser.contents, Not(HTMLContains(fork_link)))
+
+    def test_hide_fork_link_for_repos_targeting_person(self):
+        person = self.factory.makePerson()
+        another_person = self.factory.makePerson()
+        repository = self.factory.makeGitRepository(target=person)
+        browser = self.getViewBrowser(
+            repository, '+index', user=another_person)
+        self.assertDoesntContainForkLink(browser, repository, [
+            "Fork it to your account",
+            "Or click here to fork it to your account.",
+        ])
+
+    def test_show_fork_link_for_the_right_users(self):
+        another_person = self.factory.makePerson()
+        repository = self.factory.makeGitRepository()
+        repo_owner = repository.owner
+
+        # Do not show the link for the repository owner.
+        browser = self.getViewBrowser(repository, '+index', user=repo_owner)
+        self.assertDoesntContainForkLink(browser, repository, [
+            "Fork it to your account",
+            "fork it directly to your account",
+        ])
+
+        # Shows for another person.
+        browser = self.getViewBrowser(
+            repository, '+index', user=another_person)
+        self.assertContainsForkLink(
+            browser, repository, "fork it directly to your account")
+
+        # Even for another person, do not show it if the feature flag is off.
+        self.useFixture(FeatureFixture({GIT_REPOSITORY_FORK_ENABLED: ''}))
+        browser = self.getViewBrowser(
+            repository, '+index', user=another_person)
+        self.assertDoesntContainForkLink(browser, repository, [
+            "Fork it to your account",
+            "fork it directly to your account",
+        ])
+
 
 class TestGitRepositoryViewPrivateArtifacts(BrowserTestCase):
     """Tests that Git repositories with private team artifacts can be viewed.
@@ -2071,3 +2144,126 @@ class TestGitRepositoryActivityView(BrowserTestCase):
             create_activity,
             2)
         self.assertThat(recorder2, HasQueryCount.byEquality(recorder1))
+
+
+class TestGitRepositoryForkView(BrowserTestCase):
+
+    layer = DatabaseFunctionalLayer
+
+    def setUp(self):
+        super(TestGitRepositoryForkView, self).setUp()
+        self.useFixture(FeatureFixture({GIT_REPOSITORY_FORK_ENABLED: 'on'}))
+
+    def getReposOwnedBy(self, user):
+        return IGitCollection(user).getRepositories(
+            sort_by=GitListingSort.NEWEST_FIRST)
+
+    def test_fork_page_redirects_with_disabled_feature(self):
+        self.useFixture(FeatureFixture({GIT_REPOSITORY_FORK_ENABLED: ''}))
+        with admin_logged_in():
+            repository = self.factory.makeGitRepository()
+            owner = repository.owner
+        self.assertRaises(
+            Unauthorized, self.getViewBrowser,
+            repository, "+fork", rootsite="code", user=owner)
+
+    def test_fork_page_shows_input(self):
+        with admin_logged_in():
+            repository = self.factory.makeGitRepository()
+            owner = removeSecurityProxy(repository.owner)
+
+            team = self.factory.makeTeam(members=[owner])
+            another_person = self.factory.makePerson()
+
+            select_owner = Tag(
+                "owner selector", "select",
+                attrs={"id": "field.owner", "name": "field.owner"})
+
+            def person_option_tag(person):
+                return Tag(
+                    "option for %s" % person, "option",
+                    text="%s (%s)" % (person.displayname, person.name),
+                    attrs=dict(value=person.name))
+
+            option_owner = person_option_tag(owner)
+            option_team = person_option_tag(team)
+            option_another_person = person_option_tag(another_person)
+
+        browser = self.getViewBrowser(
+            repository, "+fork", rootsite="code", user=owner)
+
+        html = browser.contents
+        self.assertThat(html, HTMLContains(select_owner))
+        self.assertThat(html, HTMLContains(option_owner))
+        self.assertThat(html, HTMLContains(option_team))
+        self.assertThat(html, Not(HTMLContains(option_another_person)))
+
+    def test_fork_page_submit_to_self(self):
+        self.useFixture(GitHostingFixture())
+        repository = self.factory.makeGitRepository()
+        another_person = self.factory.makePerson()
+
+        with person_logged_in(another_person):
+            view = create_initialized_view(repository, name="+fork", form={
+                "field.owner": another_person.name,
+                "field.actions.fork": "Fork it"})
+
+            forked = self.getReposOwnedBy(another_person)[0]
+            self.assertNotEqual(forked, repository)
+            self.assertEqual(another_person, forked.owner)
+
+            notifications = view.request.response.notifications
+            self.assertEqual(1, len(notifications))
+            self.assertEqual("Repository forked.", notifications[0].message)
+
+            self.assertEqual(canonical_url(forked), view.next_url)
+
+    def test_fork_page_submit_to_team(self):
+        self.useFixture(GitHostingFixture())
+        repository = self.factory.makeGitRepository()
+        another_person = self.factory.makePerson()
+        team = self.factory.makeTeam(members=[another_person])
+
+        with person_logged_in(another_person):
+            view = create_initialized_view(repository, name="+fork", form={
+                "field.owner": team.name,
+                "field.actions.fork": "Fork it"})
+
+            forked = self.getReposOwnedBy(team)[0]
+            self.assertNotEqual(forked, repository)
+            self.assertEqual(team, forked.owner)
+
+            notifications = view.request.response.notifications
+            self.assertEqual(1, len(notifications))
+            self.assertEqual("Repository forked.", notifications[0].message)
+
+            self.assertEqual(canonical_url(forked), view.next_url)
+
+    def test_fork_page_submit_missing_user(self):
+        self.useFixture(GitHostingFixture())
+        repository = self.factory.makeGitRepository()
+        another_person = self.factory.makePerson()
+
+        with person_logged_in(another_person):
+            view = create_initialized_view(repository, name="+fork", form={
+                "field.actions.fork": "Fork it"})
+
+            # No repository should have been created.
+            self.assertEqual(0, self.getReposOwnedBy(another_person).count())
+            self.assertEqual(
+                ['You should select a valid user to fork the repository.'],
+                view.errors)
+
+            self.assertEqual(None, view.next_url)
+
+    def test_fork_page_submit_invalid_user(self):
+        self.useFixture(GitHostingFixture())
+        repository = self.factory.makeGitRepository()
+        another_person = self.factory.makePerson()
+        invalid_person = self.factory.makePerson()
+
+        with person_logged_in(another_person):
+            create_initialized_view(repository, name="+fork", form={
+                "field.owner": invalid_person.name,
+                "field.actions.fork": "Fork it"})
+            self.assertEqual(0, self.getReposOwnedBy(invalid_person).count())
diff --git a/lib/lp/code/interfaces/gitnamespace.py b/lib/lp/code/interfaces/gitnamespace.py
index 3a6e600..f4ff75a 100644
--- a/lib/lp/code/interfaces/gitnamespace.py
+++ b/lib/lp/code/interfaces/gitnamespace.py
@@ -107,8 +107,8 @@ class IGitNamespacePolicy(Interface):
         "True iff this namespace permits automatically setting a default "
         "repository on push.")
 
-    show_push_url_hints = Attribute(
-        "True if this namespace permits display of the push URL hint.")
+    supports_repository_forking = Attribute(
+        "Does this namespace support repository forking at all?")
 
     supports_merge_proposals = Attribute(
         "Does this namespace support merge proposals at all?")
diff --git a/lib/lp/code/model/gitnamespace.py b/lib/lp/code/model/gitnamespace.py
index 22e9d8f..9d72ee5 100644
--- a/lib/lp/code/model/gitnamespace.py
+++ b/lib/lp/code/model/gitnamespace.py
@@ -285,7 +285,7 @@ class PersonalGitNamespace(_BaseGitNamespace):
     supports_merge_proposals = True
     supports_code_imports = False
     allow_recipe_name_from_target = False
-    show_push_url_hints = False
+    supports_repository_forking = False
 
     def __init__(self, person):
         self.owner = person
@@ -369,7 +369,7 @@ class ProjectGitNamespace(_BaseGitNamespace):
     supports_merge_proposals = True
     supports_code_imports = True
     allow_recipe_name_from_target = True
-    show_push_url_hints = True
+    supports_repository_forking = True
 
     def __init__(self, person, project):
         self.owner = person
@@ -461,7 +461,7 @@ class PackageGitNamespace(_BaseGitNamespace):
     supports_merge_proposals = True
     supports_code_imports = True
     allow_recipe_name_from_target = True
-    show_push_url_hints = True
+    supports_repository_forking = True
 
     def __init__(self, person, distro_source_package):
         self.owner = person
@@ -553,7 +553,7 @@ class OCIProjectGitNamespace(_BaseGitNamespace):
     supports_merge_proposals = True
     supports_code_imports = True
     allow_recipe_name_from_target = True
-    show_push_url_hints = False
+    supports_repository_forking = False
 
     def __init__(self, person, oci_project):
         self.owner = person
diff --git a/lib/lp/code/model/tests/test_gitnamespace.py b/lib/lp/code/model/tests/test_gitnamespace.py
index f873782..3755bbd 100644
--- a/lib/lp/code/model/tests/test_gitnamespace.py
+++ b/lib/lp/code/model/tests/test_gitnamespace.py
@@ -24,6 +24,7 @@ from lp.code.errors import (
     GitRepositoryCreatorNotOwner,
     GitRepositoryExists,
     )
+from lp.code.interfaces.githosting import IGitHostingClient
 from lp.code.interfaces.gitnamespace import (
     get_git_namespace,
     IGitNamespace,
@@ -45,10 +46,12 @@ from lp.registry.interfaces.accesspolicy import (
     IAccessPolicyGrantFlatSource,
     IAccessPolicySource,
     )
+from lp.services.compat import mock
 from lp.testing import (
     person_logged_in,
     TestCaseWithFactory,
     )
+from lp.testing.fixture import ZopeUtilityFixture
 from lp.testing.layers import DatabaseFunctionalLayer
 
 
@@ -100,6 +103,36 @@ class NamespaceMixin:
             GitRepositoryType.HOSTED, registrant, repository_name)
         self.assertEqual([owner], list(repository.subscribers))
 
+    def test_createRepository_creates_on_githosting_sync(self):
+        hosting_client = mock.Mock()
+        self.useFixture(ZopeUtilityFixture(hosting_client, IGitHostingClient))
+        owner = self.factory.makeTeam()
+        namespace = self.getNamespace(owner)
+        repository_name = self.factory.getUniqueUnicode()
+        registrant = owner.teamowner
+        repository = namespace.createRepository(
+            GitRepositoryType.HOSTED, registrant, repository_name,
+            with_hosting=True)
+        path = repository.getInternalPath()
+        self.assertEqual(
+            [mock.call(path, clone_from=None, async_create=False)],
+            hosting_client.create.call_args_list)
+
+    def test_createRepository_creates_on_githosting_async(self):
+        hosting_client = mock.Mock()
+        self.useFixture(ZopeUtilityFixture(hosting_client, IGitHostingClient))
+        owner = self.factory.makeTeam()
+        namespace = self.getNamespace(owner)
+        repository_name = self.factory.getUniqueUnicode()
+        registrant = owner.teamowner
+        repository = namespace.createRepository(
+            GitRepositoryType.HOSTED, registrant, repository_name,
+            with_hosting=True, async_hosting=True)
+        path = repository.getInternalPath()
+        self.assertEqual(
+            [mock.call(path, clone_from=None, async_create=True)],
+            hosting_client.create.call_args_list)
+
     def test_getRepositories_no_repositories(self):
         # getRepositories on an IGitNamespace returns a result set of
         # repositories in that namespace.  If there are no repositories, the
diff --git a/lib/lp/code/templates/git-macros.pt b/lib/lp/code/templates/git-macros.pt
index 928bf83..156fd51 100644
--- a/lib/lp/code/templates/git-macros.pt
+++ b/lib/lp/code/templates/git-macros.pt
@@ -68,6 +68,11 @@
             </tt>
           </dd>
         </dl>
+        <dt tal:condition="python: getattr(view, 'allow_fork', False)">
+          <a tal:attributes="href view/fork_url" class="sprite add">
+            Fork it to your account
+          </a>
+        </dt>
       </tal:can-push>
 
       <tal:cannot-push condition="not:view/user_can_push">
@@ -83,7 +88,7 @@
              tal:content="context/owner/displayname">Team</a>
           can push to this <tal:kind replace="kind" />.
         </tal:team>
-        <dl tal:condition="context/namespace/show_push_url_hints" id="push-url">
+        <dl tal:condition="context/namespace/supports_repository_forking" id="push-url">
           <dt>To fork this repository and propose fixes from there, push to this repository:</dt>
           <dd>
             <tt class="command">
@@ -92,6 +97,12 @@
             <em>BRANCHNAME</em>
             </tt>
           </dd>
+          <dd tal:condition="python: getattr(view, 'allow_fork', False)">
+            or
+            <a tal:attributes="href view/fork_url" class="sprite add">
+              fork it directly to your account
+            </a>.
+          </dd>
         </dl>
       </tal:cannot-push>
       <p tal:condition="not:view/user/sshkeys" id="ssh-key-directions">
diff --git a/lib/lp/code/templates/gitrepository-fork.pt b/lib/lp/code/templates/gitrepository-fork.pt
 new file mode 100644
index 0000000..e656dcb
--- /dev/null
+++ b/lib/lp/code/templates/gitrepository-fork.pt
@@ -0,0 +1,22 @@
+<html
+  xmlns="http://www.w3.org/1999/xhtml"
+  xmlns:tal="http://xml.zope.org/namespaces/tal"
+  xmlns:metal="http://xml.zope.org/namespaces/metal"
+  xmlns:i18n="http://xml.zope.org/namespaces/i18n"
+  metal:use-macro="view/macro:page/main_only"
+  i18n:domain="launchpad">
+  <body>
+    <div metal:fill-slot="main">
+      <p>
+        This will create a copy of
+        <a tal:replace="structure context/fmt:link" /> in your account.
+      </p>
+      <p>
+        After the fork process, you will be able to git clone the
+        repository, push to it and create merge proposals to the original
+        repository.
+      </p>
+      <div metal:use-macro="context/@@launchpad_form/form" />
+    </div>
+  </body>
+</html>