Spring Boot App Failing to Start in Azure DevOps CD Pipeline – Need Insights!

[pratul233 (Pratul)]

Spring Boot App Failing to Start in Azure DevOps CD Pipeline – Need Insights!

Hey Tech Community!

I’m working on a CI/CD pipeline in Azure DevOps by using Jenkins as my build pipeline to deploy a Spring Boot application on an Azure LinuxVM. The Build Pipeline with Jenkins (using service hook) & deployment to Azure Linux VM was successful initially, but I faced an issue accessing the app via the browser.

Here’s my BUILD Repository which I picked from Online:

GitHub - prak233/springBoot233: contains Spring Boot Files

After tweaking the script, the pipeline now fails at the application start up stage, throwing the error:

“Spring Boot application failed to start.”
“JAR file not found!” (even though the file is present in /home/pratul/deploy/)

Debugging Steps Tried So Far:

Verified Java is installed(openjdk version "17.0.13")
Checked if the JAR file exists (ls -l confirms it’s there)
Tried manually startingthe app: java -jar spring-boot-initial-0.0.1-SNAPSHOT.jar
Used netstat -tulnp | grep 8080 to check if the port is in use
Killed existing processes on port 8080 before restart
getting this error even though correct path is given with correct permission as -rw in user level

YAML Deployment Script (Relevant Snippet)

yaml Script

• task: AzureCLI@2
  displayName: ‘Install Java & Start Spring Boot Application’
  inputs:
  azureSubscription: ‘Pay-As-You-Go’
  scriptType: ‘bash’
  scriptLocation: ‘inlineScript’
  inlineScript: |
  VM_IP=‘52.229.163.139’
  USERNAME=‘pratul’
  SSH_KEY_PATH=‘/azagent/revisit-linuxVM_key.pem’
  ssh -i $SSH_KEY_PATH -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null $USERNAME@$VM_IP << ‘EOF’

set -ex
DEPLOY_DIR=“/home/$USERNAME/deploy”
JAR_FILE=“spring-boot-initial-0.0.1-SNAPSHOT.jar”

Kill existing process on port 8080

sudo fuser -k 8080/tcp || true

Start the application

nohup java -Xmx512m -Xms256m -jar $DEPLOY_DIR/$JAR_FILE > $DEPLOY_DIR/app.log 2>&1 &
sleep 5

Verify if the process is running

if pgrep -f “$JAR_FILE”; then

echo “Spring Boot application started successfully!”

else
echo “ERROR: Spring Boot application failed to start.”
echo “App Log:”
cat $DEPLOY_DIR/app.log
exit 1
fi
EOF

Files present in “/home/pratul/deploy”

###Possible Causes?

- File permission issues? (`chmod +x` didn't help)
- Java process starting but failing silently?
- Any missing dependencies?

Has anyone encountered this issue before? What could be causing the failure despite the JAR file being present?
Any insights or debugging tips would be greatly appreciated! 🚀
#AzureDevOps #SpringBoot #CI_CD #DevOps #Azure #Linux #TechHelp #CloudComputing


```For reference here’s the full script:```
trigger:
- none
pool:

vmImage: windows-latest

stages:
- stage: BuildStage

displayName: BuildStage
jobs:

- job: CIJob
displayName: "Jenkins Build JOB"
steps:
- task: JenkinsQueueJob@2
displayName: "Queue Task"
inputs:
serverEndpoint: 'Jenkins-SRC'
jobName: 'revisit-CICD'
isMultibranchJob: true
multibranchPipelineBranch: 'feature/test'
captureConsole: true
capturePipeline: true
isParameterizedJob: false
- task: JenkinsDownloadArtifacts@2
displayName: "Download Artifact Task"
inputs:
jenkinsServerConnection: 'Jenkins-SRC'
jobName: 'revisit-CICD'
saveTo: '$(Build.StagingDirectory)'
jenkinsBuild: 'LastSuccessfulBuild'
- task: PublishBuildArtifacts@1
displayName: "Publish Artifact Task"
inputs:
PathtoPublish: '$(Build.StagingDirectory)'
ArtifactName: 'drop'
publishLocation: 'Container'
- stage: DeployStage
dependsOn: BuildStage
displayName: DeployStage
jobs:

- deployment: deploytoVM
displayName: 'deploytoVM'
environment:
name: 'MyEnv'
resourceType: VirtualMachine
tags: 'linux'
strategy:
runOnce:
deploy:
steps:
- task: DownloadPipelineArtifact@2
displayName: "Download Pipeline Build Artifact"
inputs:
artifactName: drop
targetPath: '$(pipeline.artifact)'
- task: AzureCLI@2
displayName: 'Copy Files to Linux VM'
inputs:
azureSubscription: 'Pay-As-You-Go(52ebb814-d1d8-427b-badb-92e9e2108392)'
scriptType: 'bash'
scriptLocation: 'inlineScript'
inlineScript: |
# Define variables
ARTIFACT_PATH="/azagent/_work/1/drop/initial/target/spring-boot-initial-0.0.1-SNAPSHOT.jar"
VM_IP='52.229.163.139'
USERNAME='pratul'
SSH_KEY_PATH='/azagent/revisit-linuxVM_key.pem'
ls -l $SSH_KEY_PATH
ls -l $ARTIFACT_PATH
mkdir -p /home/$USERNAME/deploy/
# chmod 664 /home/$USERNAME/deploy/
# Copy JAR file to the Linux VM
scp -i $SSH_KEY_PATH -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null $ARTIFACT_PATH $USERNAME@$VM_IP:/home/$USERNAME/deploy/
- task: AzureCLI@2
displayName: 'Install Java & Start Spring Boot Application'
inputs:
azureSubscription: 'Pay-As-You-Go(52ebb814-d1d8-427b-badb-92e9e2108392)'
scriptType: 'bash'

scriptLocation: 'inlineScript'
inlineScript: |
VM_IP='52.229.163.139'
USERNAME='pratul'
SSH_KEY_PATH='/azagent/revisit-linuxVM_key.pem'
ssh -i _KEY_PATH -o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null $USERNAME@$VM_IP << 'EOF'
set -ex
DEPLOY_DIR="/home/$USERNAME/deploy"
JAR_FILE="spring-boot-initial-0.0.1-SNAPSHOT.jar"
# Kill any existing process on port 8080

sudo fuser -k 8080/tcp || true
# Start the application and log output
nohup java -Xmx512m -Xms256m -jar \$DEPLOY_DIR/\$JAR_FILE > \$DEPLOY_DIR/app.log 2>&1 &
sleep 5
# Check if the process started

if pgrep -f "\$JAR_FILE"; then
echo "✅ Spring Boot application started successfully!"
else

echo "❌ ERROR Spring Boot application failed to start."
echo "📄 App Log:"

cat \$DEPLOY_DIR/app.log

exit 1
fi
EOF

SCREENSHOTS FOR REFERENCE