Sentry On Premise backport of https://github.com/getsentry/sentry/pull/19446 to 9.1.2 to fix slack

slack.patch

diff --git a/src/sentry/integrations/slack/integration.py b/src/sentry/integrations/slack/integration.py
index 0926a1132d..0264d10c24 100644
--- a/src/sentry/integrations/slack/integration.py
+++ b/src/sentry/integrations/slack/integration.py
@@ -75,13 +75,17 @@ class SlackIntegrationProvider(IntegrationProvider):
         'links:read',
         'links:write',
     ]) if not settings.SLACK_INTEGRATION_USE_WST else frozenset([
-        'channels:read',
-        'groups:read',
-        'users:read',
-        'chat:write',
-        'links:read',
-        'links:write',
-        'team:read',
+        "channels:read",
+        "groups:read",
+        "users:read",
+        "chat:write",
+        "links:read",
+        "links:write",
+        "team:read",
+        "chat:write.public",
+        "chat:write.customize",
+        "im:read",
+        "mpim:read",
     ])
 
     setup_dialog_config = {
diff --git a/src/sentry/integrations/slack/notify_action.py b/src/sentry/integrations/slack/notify_action.py
index 1602c4e573..7e1e72a116 100644
--- a/src/sentry/integrations/slack/notify_action.py
+++ b/src/sentry/integrations/slack/notify_action.py
@@ -1,9 +1,13 @@
 from __future__ import absolute_import
 
+import time
+import datetime
+
 from django import forms
 from django.utils.translation import ugettext_lazy as _
 
 from sentry import http
+from sentry import options
 from sentry.rules.actions.base import EventAction
 from sentry.utils import metrics, json
 from sentry.models import Integration
@@ -12,6 +16,7 @@ from .utils import build_attachment
 
 MEMBER_PREFIX = '@'
 CHANNEL_PREFIX = '#'
+SLACK_DEFAULT_TIMEOUT = 30
 strip_channel_chars = ''.join([MEMBER_PREFIX, CHANNEL_PREFIX])
 
 
@@ -41,7 +46,10 @@ class SlackNotifyServiceForm(forms.Form):
         workspace = cleaned_data.get('workspace')
         channel = cleaned_data.get('channel', '').lstrip(strip_channel_chars)
 
+        channel_prefix = None
         channel_id = self.channel_transformer(workspace, channel)
+        if channel_id:
+            channel_prefix, channel_id = channel_id
 
         if channel_id is None and workspace is not None:
             params = {
@@ -55,7 +63,6 @@ class SlackNotifyServiceForm(forms.Form):
                 params=params,
             )
 
-        channel_prefix, channel_id = channel_id
         cleaned_data['channel'] = channel_prefix + channel
         cleaned_data['channel_id'] = channel_id
 
@@ -104,6 +111,14 @@ class SlackNotifyServiceAction(EventAction):
             # Integration removed, rule still active.
             return
 
+        if not channel:
+            self.logger.warning('rule.fail.slack_post', extra={
+                'error': 'channel is none',
+                'project_id': self.project.id,
+                'project_name': self.project.name,
+            })
+            return
+
         def send_notification(event, futures):
             rules = [f.rule for f in futures]
             attachment = build_attachment(event.group, event=event, tags=tags, rules=rules)
@@ -119,7 +134,12 @@ class SlackNotifyServiceAction(EventAction):
             resp.raise_for_status()
             resp = resp.json()
             if not resp.get('ok'):
-                self.logger.info('rule.fail.slack_post', extra={'error': resp.get('error')})
+                self.logger.error('rule.fail.slack_post', extra={
+                    'error': resp.get('error'),
+                    'channel': channel,
+                    'project_id': self.project.id,
+                    'project_name': self.project.name,
+                })
 
         key = u'slack:{}:{}'.format(integration_id, channel)
 
@@ -170,6 +190,25 @@ class SlackNotifyServiceAction(EventAction):
         except Integration.DoesNotExist:
             return None
 
+        return self.get_channel_id_with_timeout(integration, name, SLACK_DEFAULT_TIMEOUT)
+
+    def get_channel_id_with_timeout(self, integration, name, timeout):
+        """
+        Fetches the internal slack id of a channel.
+        :param organization: The organization that is using this integration
+        :param integration_id: The integration id of this slack integration
+        :param name: The name of the channel
+        :return: a tuple of three values
+            1. prefix: string (`"#"` or `"@"`)
+            2. channel_id: string or `None`
+        """
+        LEGACY_LIST_TYPES = [
+            ("channels", "channels", CHANNEL_PREFIX),
+            ("groups", "groups", CHANNEL_PREFIX),
+            ("users", "members", MEMBER_PREFIX),
+        ]
+        LIST_TYPES = [("conversations", "channels", CHANNEL_PREFIX), ("users", "members", MEMBER_PREFIX)]
+
         session = http.build_session()
 
         token_payload = {
@@ -177,44 +216,64 @@ class SlackNotifyServiceAction(EventAction):
         }
 
         # Look for channel ID
-        channels_payload = dict(token_payload, **{
-            'exclude_archived': False,
-            'exclude_members': True,
-        })
-
-        resp = session.get('https://slack.com/api/channels.list', params=channels_payload)
-        resp = resp.json()
-        if not resp.get('ok'):
-            self.logger.info('rule.slack.channel_list_failed', extra={'error': resp.get('error')})
-            return None
-
-        channel_id = {c['name']: c['id'] for c in resp['channels']}.get(name)
-
-        if channel_id:
-            return (CHANNEL_PREFIX, channel_id)
-
-        # Channel may be private
-        resp = session.get('https://slack.com/api/groups.list', params=channels_payload)
-        resp = resp.json()
-        if not resp.get('ok'):
-            self.logger.info('rule.slack.group_list_failed', extra={'error': resp.get('error')})
-            return None
-
-        group_id = {c['name']: c['id'] for c in resp['groups']}.get(name)
-
-        if group_id:
-            return (CHANNEL_PREFIX, group_id)
-
-        # Channel may actually be a user
-        resp = session.get('https://slack.com/api/users.list', params=token_payload)
-        resp = resp.json()
-        if not resp.get('ok'):
-            self.logger.info('rule.slack.user_list_failed', extra={'error': resp.get('error')})
-            return None
-
-        member_id = {c['name']: c['id'] for c in resp['members']}.get(name)
-
-        if member_id:
-            return (MEMBER_PREFIX, member_id)
-
-        return None
+        channels_payload = dict(token_payload, **{"exclude_archived": True, "exclude_members": True})
+
+        if options.get("slack.legacy-app") is True:
+            list_types = LEGACY_LIST_TYPES
+        else:
+            list_types = LIST_TYPES
+            channels_payload = dict(channels_payload, **{"types": "public_channel,private_channel"})
+
+        time_to_quit = time.time() + timeout
+
+        id_data = None
+        found_duplicate = False
+        scanned_item_count = 0
+        for list_type, result_name, prefix in list_types:
+            cursor = ""
+            while True:
+                endpoint = "/%s.list" % list_type
+
+                # Slack limits the response of `<list_type>.list` to 1000 channels
+                resp = session.get('https://slack.com/api%s' % endpoint, params=dict(channels_payload, cursor=cursor, limit=100))
+                items = resp.json()
+                if not items.get('ok'):
+                    retry_after = resp.headers.get('retry-after')
+                    if retry_after:
+                        self.logger.info('rule.slack', extra={'scanned_item_count': scanned_item_count, 'time_until_timeout': datetime.timedelta(seconds=time_to_quit - time.time())})
+                        self.logger.info('rule.slack.%s_list_rate_limited' % list_type, extra={'retry_after': retry_after})
+                        time.sleep(float(retry_after))
+                        continue
+                    else:
+                        self.logger.error('rule.slack.%s_list_failed' % list_type, extra={'error': items.get('error')})
+                        return (prefix, None)
+
+                for c in items[result_name]:
+                    scanned_item_count += 1
+                    # The "name" field is unique (this is the username for users)
+                    # so we return immediately if we find a match.
+                    if c["name"] == name:
+                        return (prefix, c["id"])
+                    # If we don't get a match on a unique identifier, we look through
+                    # the users' display names, and error if there is a repeat.
+                    if list_type == "users":
+                        profile = c.get("profile")
+                        if profile and profile.get("display_name") == name:
+                            if id_data:
+                                found_duplicate = True
+                            else:
+                                id_data = (prefix, c["id"])
+
+                cursor = items.get("response_metadata", {}).get("next_cursor", None)
+                if time.time() > time_to_quit:
+                    self.logger.error('rule.slack.%s_list_timed_out' % list_type)
+                    return (prefix, None)
+
+                if not cursor:
+                    break
+            if found_duplicate:
+                return (prefix, None)
+            elif id_data:
+                return id_data
+
+        return (prefix, None)
diff --git a/src/sentry/options/defaults.py b/src/sentry/options/defaults.py
index 88ee554e1f..5f25288300 100644
--- a/src/sentry/options/defaults.py
+++ b/src/sentry/options/defaults.py
@@ -135,6 +135,8 @@ register('tagstore.multi-sampling', default=0.0)
 register('slack.client-id', flags=FLAG_PRIORITIZE_DISK)
 register('slack.client-secret', flags=FLAG_PRIORITIZE_DISK)
 register('slack.verification-token', flags=FLAG_PRIORITIZE_DISK)
+register("slack.signing-secret", flags=FLAG_PRIORITIZE_DISK)
+register("slack.legacy-app", flags=FLAG_PRIORITIZE_DISK, type=Bool, default=True)
 
 # GitHub Integration
 register('github-app.id', default=0)
diff --git a/src/sentry/utils/pytest/sentry.py b/src/sentry/utils/pytest/sentry.py
index bdc9f888ac..eac334a164 100644
--- a/src/sentry/utils/pytest/sentry.py
+++ b/src/sentry/utils/pytest/sentry.py
@@ -150,6 +150,7 @@ def pytest_configure(config):
             'slack.client-id': 'slack-client-id',
             'slack.client-secret': 'slack-client-secret',
             'slack.verification-token': 'slack-verification-token',
+            "slack.legacy-app": True,
 
             'github-app.name': 'sentry-test-app',
             'github-app.client-id': 'github-client-id',