APM Web Application

A simple application built using Wt. Similar to the Desktop application, the primary purpose of this application is to display APM records as forrests that follow the function call chain for instrumented services/applications.

This application is intended to deploy in the same network as QuestDb. Unlike the desktop application, this application connects to QuestDB over the Postgres Wire Protocol, to retrieve data.

Features

The application provides two views:

List View Display the parent APM records (generally those where the type column is null) in a table. The query used to retrieve the parent APM records is editable. Change the query as appropriate to filter by additional conditions, time range, etc. Double-click a row to display a tree view with all the child process records for the parent APM record.
** Tree View** Display a tree with all the child process records for the latest parent APM records. Select rows in the tree to view all available data for the record.

Configuration

The application has very minimal configuration options. The following environment variables can be used to control the aspects that are configurable.

APM_USERNAME The username to use to log in to the application. Defaults to apmuser.
APM_PASSWORD The password to use to log in to the application.
QUESTDB_URI The PostgreSQL connection URI. Default postgresql://user:quest@localhost:8812/qdb
APM_TABLE The database table that holds the APM records. Defaults to webapm. Only one table is supported by the application at present.
SECURE_COOKIE Specify true to set secure cookies (requires https). Cookies are used to track login sessions.

Authentication

There is a rudimentary (and quite insecure) authentication layer for the application. This is just to ensure that the application is not publicly accessible if deployed on the internet. Ideally, the application is deployed in a private network, and accessible only over VPN. The username and password combination for logging in can be controlled via environment variables.

Build

Wt is the primary dependency for building the project.

Install Wt

Install Wt and the dependencies needed by Wt.

#!/bin/ksh DEST='/usr/local/wt' if [ -d $DEST ] then sudo rm -rf $DEST fi cd /tmp if [ -d wt ] then rm -rf wt fi git clone --branch 4.11.4 https://github.com/emweb/wt.git cd wt CXXFLAGS='-I/opt/homebrew/opt/openssl/include -Wno-deprecated-declarations' LDFLAGS='-L/opt/homebrew/opt/openssl/lib' cmake \ -DAPPLE=true \ -DCMAKE_CXX_STANDARD=17 \ -DCMAKE_BUILD_TYPE=RelWithDebInfo \ -DBOOST_ROOT=/usr/local/boost \ -DBoost_USE_STATIC_RUNTIME=ON \ -DBoost_USE_MULTITHREADED=ON \ -DSHARED_LIBS=OFF \ -DENABLE_HARU=ON \ -DHARU_PREFIX=/opt/homebrew/opt/libharu \ -DENABLE_PANGO=OFF \ -DENABLE_OPENGL=OFF \ -DBUILD_EXAMPLES=OFF \ -DINSTALL_EXAMPLES=ON \ -DINSTALL_RESOURCES=ON \ -DINSTALL_THEMES=ON \ -DENABLE_UNWIND=ON \ -DMULTI_THREADED=ON \ -DENABLE_LIBWTTEST=OFF \ -DEXAMPLES_DESTINATION=examples \ -DCMAKE_INSTALL_PREFIX=$DEST \ -B build -S . cmake --build build -j12 && sudo cmake --install build)

Install Application

Check out the sources and use cmake to build the application.

git clone https://github.com/sptrakesh/apm-viewer.git
cd apm-viewer
cmake -DCMAKE_BUILD_TYPE=Release -B build -S .
cmake --build build --parallel
docker/build.sh # builds docker image locally

Run the application using a command similar to the following:

cd <path to>/apm-viewer
(cd build/src; ./apm-app --docroot ../../resources/docroot --approot ../../resources/approot --http-port 8000 --http-address 0.0.0.0 --resources-dir /usr/local/wt/share/Wt/resources --deploy-path /a -c ../../resources/wt_config.xml)

Docker

A docker image is available for the web application.

Environment variables

The following variables can be used to customise the service. The QuestDB URI variable as specified earlier, except there is no default value.

QUESTDB_URI The PostgreSQL connection URI.
PORT Specify the port on which the server listens to. Default 8000.

It is recommended to volume mount a /tmp/apm-sessions.json file, which is used to track sessions. This allows sessions to survive service restarts.

docker pull questdb/questdb
docker pull sptrakesh/apm-app
exists=`docker network ls | grep spt-net`
if [ -z "$exists" ]
then
  docker network create --driver bridge spt-net
fi
docker run -d --rm \
  -v "$HOME/tmp/spt/questdb:/var/lib/questdb" \
  -e QDB_PG_READONLY_USER_ENABLED=true \
  -p 9000:9000 -p 9009:9009 -p 8812:8812 -p 9003:9003 \
  --network spt-net \
  --name questdb questdb/questdb
touch $HOME/tmp/spt/apm-sessions.json
docker run --rm -d \
  -e "APM_USERNAME=apm" \
  -e "APM_PASSWORD=apm" \
  -e "QUESTDB_URI=postgresql://user:quest@questdb:8812/qdb" \
  -v "$HOME/tmp/spt/apm-sessions.json:/tmp/apm-sessions.json" \
  -p 8000:8000 \
  --network spt-net \
  --name apm-app \
  sptrakesh/apm-app
# ... after use
docker stop apm-app questdb

Once started, the application can be accessed at http://localhost:8000/a

Screen captures

Last modified: 30 April 2025