1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
|
---
stage: Deploy
group: Environments
info: To determine the technical writer assigned to the Stage/Group associated with this page, see https://handbook.gitlab.com/handbook/product/ux/technical-writing/#assignments
---
# Web terminals (deprecated) **(FREE SELF)**
> - [Deprecated](https://gitlab.com/groups/gitlab-org/configure/-/epics/8) in GitLab 14.5.
> - [Disabled on self-managed](https://gitlab.com/gitlab-org/gitlab/-/issues/353410) in GitLab 15.0.
WARNING:
This feature was [deprecated](https://gitlab.com/groups/gitlab-org/configure/-/epics/8) in GitLab 14.5.
FLAG:
On self-managed GitLab, by default this feature is not available. To make it available, an administrator can [enable the feature flag](../../administration/feature_flags.md) named `certificate_based_clusters`.
- Read more about the non-deprecated [Web Terminals accessible through the Web IDE](../../user/project/web_ide/index.md).
- Read more about the non-deprecated [Web Terminals accessible from a running CI job](../../ci/interactive_web_terminal/index.md).
---
With the introduction of the [Kubernetes integration](../../user/infrastructure/clusters/index.md),
GitLab can store and use credentials for a Kubernetes cluster.
GitLab uses these credentials to provide access to
[web terminals](../../ci/environments/index.md#web-terminals-deprecated) for environments.
NOTE:
Only users with at least the [Maintainer role](../../user/permissions.md) for the project access web terminals.
## How it works
A detailed overview of the architecture of web terminals and how they work
can be found in [this document](https://gitlab.com/gitlab-org/gitlab-workhorse/blob/master/doc/channel.md).
In brief:
- GitLab relies on the user to provide their own Kubernetes credentials, and to
appropriately label the pods they create when deploying.
- When a user navigates to the terminal page for an environment, they are served
a JavaScript application that opens a WebSocket connection back to GitLab.
- The WebSocket is handled in [Workhorse](https://gitlab.com/gitlab-org/gitlab-workhorse),
rather than the Rails application server.
- Workhorse queries Rails for connection details and user permissions. Rails
queries Kubernetes for them in the background using [Sidekiq](../sidekiq/sidekiq_troubleshooting.md).
- Workhorse acts as a proxy server between the user's browser and the Kubernetes
API, passing WebSocket frames between the two.
- Workhorse regularly polls Rails, terminating the WebSocket connection if the
user no longer has permission to access the terminal, or if the connection
details have changed.
## Security
GitLab and [GitLab Runner](https://docs.gitlab.com/runner/) take some
precautions to keep interactive web terminal data encrypted between them, and
everything protected with authorization guards. This is described in more
detail below.
- Interactive web terminals are completely disabled unless [`[session_server]`](https://docs.gitlab.com/runner/configuration/advanced-configuration.html#the-session_server-section) is configured.
- Every time the runner starts, it generates an `x509` certificate that is used for a `wss` (Web Socket Secure) connection.
- For every created job, a random URL is generated which is discarded at the end of the job. This URL is used to establish a web socket connection. The URL for the session is in the format `(IP|HOST):PORT/session/$SOME_HASH`, where the `IP/HOST` and `PORT` are the configured [`listen_address`](https://docs.gitlab.com/runner/configuration/advanced-configuration.html#the-session_server-section).
- Every session URL that is created has an authorization header that needs to be sent, to establish a `wss` connection.
- The session URL is not exposed to the users in any way. GitLab holds all the state internally and proxies accordingly.
## Enabling and disabling terminal support
NOTE:
AWS Classic Load Balancers do not support web sockets.
If you want web terminals to work, use AWS Network Load Balancers.
Read [AWS Elastic Load Balancing Product Comparison](https://aws.amazon.com/elasticloadbalancing/features/#compare)
for more information.
As web terminals use WebSockets, every HTTP/HTTPS reverse proxy in front of
Workhorse must be configured to pass the `Connection` and `Upgrade` headers
to the next one in the chain. GitLab is configured by default to do so.
However, if you run a [load balancer](../load_balancer.md) in
front of GitLab, you may need to make some changes to your configuration. These
guides document the necessary steps for a selection of popular reverse proxies:
- [Apache](https://httpd.apache.org/docs/2.4/mod/mod_proxy_wstunnel.html)
- [NGINX](https://www.nginx.com/blog/websocket-nginx/)
- [HAProxy](https://www.haproxy.com/blog/websockets-load-balancing-with-haproxy)
- [Varnish](https://varnish-cache.org/docs/4.1/users-guide/vcl-example-websockets.html)
Workhorse doesn't let WebSocket requests through to non-WebSocket endpoints, so
it's safe to enable support for these headers globally. If you prefer a
narrower set of rules, you can restrict it to URLs ending with `/terminal.ws`.
This approach may still result in a few false positives.
If you self-compiled your installation, you may need to make some changes to your configuration. Read
[Upgrading Community Edition and Enterprise Edition from source](../../update/upgrading_from_source.md#nginx-configuration)
for more details.
To disable web terminal support in GitLab, stop passing
the `Connection` and `Upgrade` hop-by-hop headers in the *first* HTTP reverse
proxy in the chain. For most users, this is the NGINX server bundled with
Linux package installations. In this case, you need to:
- Find the `nginx['proxy_set_headers']` section of your `gitlab.rb` file
- Ensure the whole block is uncommented, and then comment out or remove the
`Connection` and `Upgrade` lines.
For your own load balancer, just reverse the configuration changes recommended
by the above guides.
When these headers are not passed through, Workhorse returns a
`400 Bad Request` response to users attempting to use a web terminal. In turn,
they receive a `Connection failed` message.
## Limiting WebSocket connection time
By default, terminal sessions do not expire. To limit the terminal session
lifetime in your GitLab instance:
1. On the left sidebar, at the bottom, select **Admin Area**.
1. Select **Settings > Web terminal**.
1. Set a `max session time`.
|
