mirror of
https://github.com/gravitational/teleport
synced 2024-10-21 17:53:28 +00:00
90 lines
3 KiB
Go
90 lines
3 KiB
Go
/*
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Copyright 2015 Gravitational, Inc.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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/*
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package reversetunnel provides interfaces for accessing remote clusters
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via reverse tunnels and directly.
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Reverse Tunnels
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Proxy server Proxy agent
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Reverse tunnel
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+----------+ +---------+
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| <----------------------+ |
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+-----+----------+ +---------+-----+
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+----------------+ +---------------+
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Proxy Cluster "A" Proxy Cluster "B"
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Reverse tunnel is established from a cluster "B" Proxy
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to the a cluster "A" proxy, and clients of the cluster "A"
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can access servers of the cluster "B" via reverse tunnel connection,
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even if the cluster "B" is behind the firewall.
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Multiple Proxies and Revese Tunnels
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With multiple proxies behind the load balancer,
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proxy agents will eventually discover and establish connections to all
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proxies in cluster.
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* Initially Proxy Agent connects to Proxy 1.
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* Proxy 1 starts sending information about all available proxies
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that have not received connection from the Proxy Agent yet. This
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process is called "sending discovery request".
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+----------+
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| <--------+
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+----------+ | +-----------+ +----------+
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Proxy 1 +-------------------------------+ |
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+-----------+ +----------+
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Load Balancer Proxy Agent
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+----------+
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+----------+
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Proxy 2
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* Agent will use the discovery request to establish new connections
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and check if it has connected and "discovered" all the proxies specified
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in the discovery request.
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* Assuming that load balancer uses fair load balancing algorithm,
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agent will eventually discover and connect back to all the proxies.
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+----------+
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| <--------+
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+----------+ | +-----------+ +----------+
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Proxy 1 +-------------------------------+ |
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| +-----------+ +----------+
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| Load Balancer Proxy Agent
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+----------+ |
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| <--------+
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+----------+
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Proxy 2
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*/
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package reversetunnel
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