web ui no longer loads

Hello,

using an official docker traccar/traccar:latest, web ui stopped loading, web port is properly listening, can connect to TCP socket, on web connection I only now get spinning blue circle and login prompt no longer shows.

no obvious errors in the log, on restart get usual startup messages. data ports keep getting structured data.

2019-12-25 11:04:24  INFO: Logging initialized @3251ms to org.eclipse.jetty.util.log.Slf4jLog
2019-12-25 11:04:25  INFO: Operating system name: Linux version: 4.15.0-72-generic architecture: amd64
2019-12-25 11:04:25  INFO: Java runtime name: OpenJDK 64-Bit Server VM vendor: IcedTea version: 25.212-b04
2019-12-25 11:04:25  INFO: Memory limit heap: 491mb non-heap: 0mb
2019-12-25 11:04:25  INFO: Character encoding: UTF-8 charset: UTF-8
2019-12-25 11:04:25  INFO: Version: 4.6
2019-12-25 11:04:25  INFO: Starting server...
2019-12-25 11:04:25  INFO: jetty-9.4.20.v20190813; built: 2019-08-13T21:28:18.144Z; git: 84700530e645e812b336747464d6fbbf370c9a20; jvm 1.8.0_212-b04
2019-12-25 11:04:25  INFO: Started o.t.w.@4993febc{/,null,AVAILABLE}
2019-12-25 11:04:25  INFO: DefaultSessionIdManager workerName=node0
2019-12-25 11:04:25  INFO: No SessionScavenger set, using defaults
2019-12-25 11:04:25  INFO: node0 Scavenging every 660000ms
2019-12-25 11:04:26  INFO: Started o.e.j.s.ServletContextHandler@443a53df{/,null,AVAILABLE}
2019-12-25 11:04:26  INFO: Started ServerConnector@46292372{HTTP/1.1,[http/1.1]}{0.0.0.0:8083}
2019-12-25 11:04:26  INFO: Started @4957ms

I have tried adding web debug to my traccar.xml but does not give me any more logging data

<entry key='web.debug'>true</entry>

it used to work just fine up until recently, no conifg change. any idea?

thank you

What troubleshooting have you done so far?

Hi Anton,

I did the following:

restarted the docker,
checked the logs,
checked the processes (java -Xms512m -Xmx512m -Djava.net.preferIPv4Stack=true -jar tracker-server.jar conf/traccar.xml) is running fine,
checked the listening ports,
started a private browser to avoid all cached content, cookies,
did a packet capture - jetty running fine, serving all of the java script files to the browser, the last loaded is
GET /l10n/en.json?_dc=1577292377384 HTTP/1.1
TCP session closes by the server sending FIN shortly after

managed to increase the logging by adding

    <entry key='logger.level'>all</entry>

got overwhelmed with all of the debug logging, find many of the following timeouts in the log (not sure if these are most relevant)

2019-12-25 18:07:48 DEBUG: onFail FillInterest@7e689fa2{AC.ReadCB@4fedd28d{HttpConnection@4fedd28d::SocketChannelEndPoint@1726c4{/127.0.0.1:39106<->/127.0.0.1:8083,OPEN,fill=FI,flush=-,to=30001/30000}{io=1/1,kio=1,kro=1}->HttpConnection@4fedd28d[p=HttpParser{s=START,0 of -1},g=HttpGenerator@7675ecb2{s=START}]=>HttpChannelOverHttp@ed0d8b6{r=5,c=false,c=false/false,a=IDLE,uri=null,age=0}}} - Idle timeout expired: 30000/30000 ms - TimeoutException (...)
2019-12-25 18:07:48 DEBUG: ignored: WriteFlusher@7b4d51c4{IDLE}->null - Idle timeout expired: 30000/30000 ms - TimeoutException (...)
2019-12-25 18:07:53 DEBUG: ignored: WriteFlusher@3c61b11f{IDLE}->null - ClosedChannelException (...)

Have you checked browser console?

@Anton

Bingo! thanks. indeed, launched javascript console and got these errors

cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v5.3.0/css/ol.css:1 Failed to load resource: net::ERR_CONNECTION_REFUSED
cdn.jsdelivr.net/gh/openlayers/openlayers.github.io@master/en/v5.3.0/build/ol.js:1 Failed to load resource: net::ERR_CONNECTION_REFUSED
cdn.jsdelivr.net/npm/proj4@2.5.0/dist/proj4.js:1 Failed to load resource: net::ERR_CONNECTION_REFUSED

it became obvious the issue was on my client side.

looking into this further I have realised it was my DNS stripping solution (adguard home) that started blocking "cdn.jsdelivr.net"

I have whitelisted it and I am back in business.

@Anton! Many thanks for a prompt help.