DHIS 2 web request gives "Invalid character found in the request target. The valid characters are defined in RFC 7230 and RFC 3986"

Question

When opening the DHIS 2 Tracker capture app, the AP request for the me resource leads to a 400 client side error. When looking in the Tomcat logs I see:

Invalid character found in the request target. The valid characters are defined in RFC 7230 and RFC 3986

I am running Tomcat 8.5. What is the reason for this?

Answer 1

This happens because DHIS 2 uses brackets in some of their URLs, and because Tomcat version 8.5 later has prohibited the use of brackets in URLs.

The DHIS 2 team is working on a change in the API syntax to avoid the use of brackets, and to encode all API request URLs.

A short-term fix is to configure Tomcat to allow for brackets through the relaxedQueryChars connector attribute. Open the following file:

/tomcat-dir/conf/server.xml

and add relaxedQueryChars="[]" to the HTTP connector element:

<Connector protocol="HTTP/1.1"
  port="8080" 
  relaxedQueryChars="[]" />

This will allow brackets in URLs and DHIS 2 will function as before.

Answer 2

This has since been resolved by DHIS2-5081. Going forward, this should not be a problem with DHIS2 2.29 and newer.

For older versions, it is still required to change the Tomcat configuration as outlined by Lars.