TeamCity On-Premises 2023.11 Help

Configuring Proxy Server

This article gives general recommendations on configuring the following proxy types:

Set Up TeamCity Server Behind Proxy

Consider the example:
TeamCity server is installed at a local URL http://teamcity.local:8111/tc.
It is visible to the outside world as a public URL http://teamcity.public:400/tc.

To make sure TeamCity "knows" the actual absolute URLs used by the client to access the resources, you need to:

  • Set up a reverse proxy as described below.

  • Configure the Tomcat server bundled with TeamCity.

These URLs are used to generate absolute URLs in the client redirects and other responses.

After configuring the proxy, you will also need to change the Server URL value in TeamCity Global Settings to the proxy URL.

Note: An internal TeamCity server should work under the same context (that is part of the URL after the host name) as it is visible from outside by an external address. See also the TeamCity server context changing instructions.
If you need to run the server under a different context, note that the context-changing proxy should conceal this fact from the TeamCity: for example, it should map server redirect URLs as well as cookies setting paths to the original (external) context.

The proxy should be configured with the generic web security in mind. Headers like Referer and Origin and all unknown headers should be passed to the TeamCity web application in the unmodified form. For example, TeamCity relies on the X-TC-CSRF-Token header added by the clients.


Versions 2.4.5 or later are recommended. Earlier versions do not support the WebSocket protocol.

When using Apache, make sure to use the Dedicated "Connector" node approach for configuring TeamCity server.

LoadModule proxy_module /usr/lib/apache2/modules/ LoadModule proxy_http_module /usr/lib/apache2/modules/ LoadModule headers_module /usr/lib/apache2/modules/ LoadModule proxy_wstunnel_module /usr/lib/apache2/modules/ ProxyRequests Off ProxyPreserveHost On ProxyPass /tc/app/subscriptions ws://teamcity.local:8111/tc/app/subscriptions connectiontimeout=240 timeout=1200 ProxyPassReverse /tc/app/subscriptions ws://teamcity.local:8111/tc/app/subscriptions ProxyPass /tc http://teamcity.local:8111/tc connectiontimeout=240 timeout=1200 ProxyPassReverse /tc http://teamcity.local:8111/tc ## The following entries are required to allow the Agent Terminal feature to function with websockets ProxyPass /tc/plugins/teamcity-agent-terminal/ ws://teamcity.local:8111/tc/plugins/teamcity-agent-terminal/ connectiontimeout=240 timeout=1200 ProxyPassReverse /tc/plugins/teamcity-agent-terminal/ ws://teamcity.local:8111/tc/plugins/teamcity-agent-terminal/ ProxyPass /tc/app/agentTerminal/ ws://teamcity.local:8111/tc/app/agentTerminal/ connectiontimeout=240 timeout=1200 ProxyPassReverse /tc/app/agentTerminal/ ws://teamcity.local:8111/tc/app/agentTerminal/

Note the order of the ProxyPass rules: conflicting ProxyPass rules must be sorted starting with the longest URLs first.

By default, Apache allows only a limited number of parallel connections that may be insufficient when using the WebSocket protocol. For instance, it may result in the TeamCity server not responding when a lot of clients open the web UI. To fix it, you may need to fine-tune the Apache configuration.

For example, on Unix, you should switch to mpm_worker and configure the maximum number of simultaneous connections:

<IfModule mpm_worker_module> ServerLimit 100 StartServers 3 MinSpareThreads 25 MaxSpareThreads 75 ThreadLimit 64 ThreadsPerChild 25 MaxClients 2500 MaxRequestsPerChild 0 </IfModule>

On Windows, you may need to increase the ThreadsPerChild value as described in the Apache documentation.


Versions 1.3 or later are recommended. Earlier versions do not support the WebSocket protocol.

http { ... default settings here proxy_read_timeout 1200; proxy_connect_timeout 240; client_max_body_size 0; # maximum size of an HTTP request. 0 allows uploading large artifacts to TeamCity map $http_upgrade $connection_upgrade { # WebSocket support default upgrade; '' ''; } server { listen 400; # public server port server_name teamcity.public; # public server host name location / { # public context (should be the same as internal context) proxy_pass http://teamcity.local:8111; # full internal address proxy_http_version 1.1; proxy_set_header Host $server_name:$server_port; proxy_set_header X-Forwarded-Host $http_host; # necessary for proper absolute redirects and TeamCity CSRF check proxy_set_header X-Forwarded-Proto $scheme; proxy_set_header X-Forwarded-For $remote_addr; proxy_set_header Upgrade $http_upgrade; # WebSocket support proxy_set_header Connection $connection_upgrade; # WebSocket support } } }


To configure a TeamCity server behind an IIS reverse proxy:

  1. Create a canonical name (CNAME) record for your TeamCity server.

  2. Issue a certificate that will ensure a secure connection between the TeamCity server and external users. If the certificate was issued not by well-known certificate authority, you may need to manually add it to the Java Certificate Store on every machine that connects to TeamCity:

    keytool -importcert -file <cert file> -keystore <path to JRE installation>/lib/security/cacerts
  3. Change the server URL to the proxy URL.

  4. Edit the <TeamCity_Home_Directory>/conf/server.xml file to set up required TeamCity Tomcat server properties as described in the TeamCity Tomcat Configuration section.

  5. Steps 5 to 8 are perfomed in Powershell. Use the Get-IISConfigSection and Set-IISConfigAttributeValue cmdlets to enable SSL flags:

    $ConfigSectionTC = Get-IISConfigSection -SectionPath "system.webServer/security/access" -Location "TCProxy"; Set-IISConfigAttributeValue -AttributeName sslFlags -AttributeValue Ssl -ConfigElement $ConfigSectionTC;
  6. Use the Set-WebConfigurationProperty cmdlet to add a server variable that allows the HTTP forwarded IP to be passed from the web requests:

    Set-WebConfigurationProperty -pspath "IIS:/" -Location "TCProxy" -filter "system.webServer/rewrite/allowedServerVariables" -name "." -value @{name="HTTP_FORWARDED"} -FORCE
  7. Enable proxy setting:

    Set-WebConfigurationProperty -pspath "MACHINE/WEBROOT/APPHOST" -filter "system.webServer/proxy" -name "." -value @{ enabled="true" } -FORCE
  8. Disable the reverseRewriteHostInResponseHeaders parameter if you're using an external storage for TeamCity artifacts:

    Set-WebConfigurationProperty -pspath "MACHINE/WEBROOT/APPHOST" -filter "system.webServer/proxy" -name "." -value @{ reverseRewriteHostInResponseHeaders="false" } -FORCE
  9. Modify the IIS web.config file as follows:

    <?xml version="1.0" encoding="UTF-8"?> <configuration> <system.web> <httpRuntime requestPathInvalidCharacters="" /> </system.web> <system.webServer> <rewrite> <rules useOriginalURLEncoding="true"> <rule name="teamcity" enabled="true" patternSyntax="Wildcard" stopProcessing="true"> <match url="*" /> <action type="Rewrite" url="http://localhost:80/{R:0}" /> <serverVariables> <set name="HTTP_FORWARDED" value="for={REMOTE_ADDR};by={LOCAL_ADDR};host=&quot;{HTTP_HOST}&quot;;proto=&quot;https&quot;" /> </serverVariables> </rule> </rules> </rewrite> <security> <requestFiltering allowDoubleEscaping="true"> <fileExtensions> <remove fileExtension=".config" /> </fileExtensions> <hiddenSegments> <remove segment="bin" /> </hiddenSegments> </requestFiltering> </security> </system.webServer> </configuration>

Other Servers

Make sure to use a performant proxy with due (high) limits on request (upload) and response (download) size and timeouts (at least tens of minutes and gigabyte, according to the sizes of the codebase and artifacts).

It is recommended to use a proxy capable of working with the WebSocket protocol as this helps the UI to refresh quicker.

Generally, you need to configure the TeamCity server so that it "knows" about the original URL used by the client and can generate correct absolute URLs accessible for the client. The preferred way to achieve that is to pass the original Host header to TeamCity. An alternative method is to set X-Forwarded-Host header to the original Host header's value.

Note that whenever the value of the Host header is changed by the proxy (while it is recommended to preserve the original Host header value) and no X-Forwarded-Host header with the original Host value is provided, the values of the Origin and Referer headers should be mapped correspondingly if they contain the original Host header value (if they do not, they should not be set in order not to circumvent TeamCity CSRF protection).

Select a proper approach from the section below and configure the proxy accordingly.

Common Misconfigurations

Check that your reverse proxy (or a similar tool) conforms to the following requirements:

  • URLs with paths starting with a dot (.) are supported (path to hidden artifacts start contain the .teamcity directory).

  • URLs with a colon (:) are supported (many TeamCity resources use the colon). Related IIS setting. Symptom: build has no artifacts with the "No user-defined artifacts in this build" text even if there are artifacts.

  • Settings that limit the maximum request name, response length, and response time are not too restrictive. See this article for more information: IIS-Related Issues.

  • gzip Content-Encoding is fully supported. For example, certain IIS configurations can result in the "Loading data..." in the UI and 500 HTTP responses (see the related issue).

IIS-related issues:

  • If the "PKIX path building failed: unable to find valid certification path to requested target" error occurs, add your certificate to the same Java keystore TeamCity is using.

  • If an incorrect server name is returned in HTTP 404 or 50x errors, check your redirect rules and the forwarded header.

TeamCity Tomcat Configuration

For a TeamCity Tomcat configuration, use the dedicated "Connector" node in the server configuration with hard-coded public URL details and make sure the port configured in the connector is used only by the requests to the public URL configured.

This approach can be used with any proxy configuration, provided the configured port is receiving requests only to the configured public URL.

You need to change the "Connector" node in <TeamCity Home>/conf/server.xml file as below.

<Connector port="8111" protocol="org.apache.coyote.http11.Http11NioProtocol" connectionTimeout="60000" useBodyEncodingForURI="true" socket.txBufSize="64000" socket.rxBufSize="64000" tcpNoDelay="1" secure="false" scheme="http" />

When the public server address is HTTPS, use the secure="true" and scheme="https" attributes. If these attributes are missing, TeamCity will show a respective health report.

If a TeamCity server is configured behind an IIS reverse proxy:

<Connector port="80" protocol="org.apache.coyote.http11.Http11NioProtocol" connectionTimeout="60000" redirectPort="8543" useBodyEncodingForURI="true" socket.txBufSize="64000" socket.rxBufSize="64000" tcpNoDelay="1" proxyName="<your_CNAME_value>" proxyPort="443" secure="true" scheme="https" /> <Valve className="org.apache.catalina.valves.RemoteIpValve" remoteIpHeader="x-forwarded-for" protocolHeader="x-forwarded-proto" portHeader="x-forwarded-port" internalProxies="<internal_proxy_ip>" />

Use Proxy for Outgoing TeamCity Server Connections

This section describes configuring TeamCity to use a proxy server for outgoing HTTP connections. To connect TeamCity behind a proxy to Amazon EC2 cloud agents, see this section.

A TeamCity server can use a proxy server for certain outgoing HTTP connections to other services like issues trackers.

To point TeamCity to your proxy server, set the following internal properties:

# For HTTP protocol ## The domain name or the IP address of the proxy host and the port: teamcity.http.proxyPort=8080   ## The hosts that should be accessed without going through the proxy, usually internal hosts. Provide a list of hosts, separated by the '|' character. The wildcard '*' can be used: teamcity.http.nonProxyHosts=localhost|*   ## For an authenticated proxy add the following properties: ### Authentication type. "basic" and "ntlm" values are supported. The default is basic. teamcity.http.proxyAuthenticationType=basic ### Login and Password for the proxy: teamcity.http.proxyLogin=username teamcity.http.proxyPassword=password   # For HTTPS protocol ## The domain name or the IP address of the proxy host and the port: teamcity.https.proxyPort=8080   ## The hosts that should be accessed without going through the proxy, usually internal hosts. Provide a list of hosts, separated by the '|' character. The wildcard '*' can be used: teamcity.https.nonProxyHosts=localhost|*   ## For an authenticated proxy add the following properties: ### Authentication type. "basic" and "ntlm" values are supported. The default is basic. teamcity.https.proxyAuthenticationType=basic ### Login and Password for the proxy: teamcity.https.proxyLogin=login teamcity.https.proxyPassword=password

Use Proxy for Outgoing Build Agent Connections

A build agent typically needs to make a variety of outbound connections: to the TeamCity server, to S3 artifact storage, to VCS hosts, and so on. This section describes how to configure the build agent so that the outbound connections continue to work after the build agent is deployed behind a proxy.

On the TeamCity agent side, specify the proxy to connect to the TeamCity server using the following properties in the file:

## The domain name or the IP address of the proxy host and the port teamcity.http.proxyHost=123.45.678.9 teamcity.http.proxyPort=8080   ## If the proxy requires authentication, specify the login and password teamcity.http.proxyLogin=login teamcity.http.proxyPassword=password

If the proxy has a HTTPS endpoint, you can also configure the teamcity.https.* properties.

Note that the proxy has to be configured not to cache any TeamCity server responses. For example, if you use Squid, add "cache deny all" line to the squid.conf file.

Proxy Server for Multinode Setup

The TeamCity server can be configured to use multiple nodes (or servers) for high availability and flexible load distribution. Refer to this article for the examples of NGINX and HAProxy configurations: Multinode Setup for High Availability.

Last modified: 14 December 2023