Hi garfty

You need to do "showDirectlyInBrowser: true" - in this case everything should be ok. Maybe setting `userMedata` to "ContentType: application/json" will be required.

To be honest I don't know reason behind setting "application/octet-stream" by default. But I believe that it was done on purpose

Hi Alexander,

Thanks for the speedy response, I've just had a chance to test out setting showDirectlyInBrowser: true however it made no difference to the file when uploaded. When I add the following:

step([$class: 'S3BucketPublisher', consoleLogLevel: 'INFO', dontWaitForConcurrentBuildCompletion: false, entries: [[
bucket: 'x.x.tech',
excludedFile: '',
flatten: false,
gzipFiles: false,
keepForever: true,
managedArtifacts: false,
noUploadOnFailure: true,
selectedRegion: 'eu-west-1',
showDirectlyInBrowser: true,
sourceFile: "path/**",
storageClass: 'STANDARD',
uploadFromSlave: false,
useServerSideEncryption: true
]], pluginFailureResultConstraint: 'FAILURE', profileName: 'x-profile', userMetadata: [
"ContentType": "application/json"
]])

It throws the following error:

userMetadata: MetadataPair(key: String, value: String)[], dontWaitForConcurrentBuildCompletion: boolean, consoleLogLevel: String, pluginFailureResultConstraint: String): java.lang.UnsupportedOperationException: must specify $class with an implementation of interface java.util.List

I'll keep digging and let you know if I find anything else.

I've finally got around to looking back in to this, and got a little further, now my builds are just unstable

step([
$class: 'S3BucketPublisher',
consoleLogLevel: 'INFO',
dontWaitForConcurrentBuildCompletion: false,
entries: [[
bucket: 'x-bucket',
excludedFile: '',
flatten: false,
gzipFiles: false,
keepForever: true,
managedArtifacts: false,
noUploadOnFailure: true,
selectedRegion: 'eu-west-1',
showDirectlyInBrowser: true,
sourceFile: "path/**/*.json",
storageClass: 'STANDARD',
uploadFromSlave: false,
useServerSideEncryption: true
]],
pluginFailureResultConstraint: 'FAILURE',
profileName: 'x-profile',
userMetadata: [[
"Content-Type": "application/json"
]]
])

This results in the following:

ERROR: Failed to upload files java.io.IOException: Call fails for Destination [bucketName=x-bucket, objectName=path/test.json]: java.lang.NullPointerException:: Failed after 5 tries. at hudson.plugins.s3.S3Profile.repeat(S3Profile.java:262) at hudson.plugins.s3.S3Profile.upload(S3Profile.java:155) at hudson.plugins.s3.S3BucketPublisher.perform(S3BucketPublisher.java:254) at org.jenkinsci.plugins.workflow.steps.CoreStep$Execution.run(CoreStep.java:78) at org.jenkinsci.plugins.workflow.steps.CoreStep$Execution.run(CoreStep.java:65) at org.jenkinsci.plugins.workflow.steps.SynchronousNonBlockingStepExecution$1$1.call(SynchronousNonBlockingStepExecution.java:49) at hudson.security.ACL.impersonate(ACL.java:260) at org.jenkinsci.plugins.workflow.steps.SynchronousNonBlockingStepExecution$1.run(SynchronousNonBlockingStepExecution.java:46) at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:473) at java.util.concurrent.FutureTask.run(FutureTask.java:262) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) at java.lang.Thread.run(Thread.java:745) Caused by: java.lang.NullPointerException at hudson.plugins.s3.callable.S3BaseUploadCallable.buildMetadata(S3BaseUploadCallable.java:62) at hudson.plugins.s3.callable.S3UploadCallable.invoke(S3UploadCallable.java:26) at hudson.plugins.s3.callable.S3UploadCallable.invoke(S3UploadCallable.java:14) at hudson.plugins.s3.S3Profile.invoke(S3Profile.java:195) at hudson.plugins.s3.S3Profile.access$000(S3Profile.java:29) at hudson.plugins.s3.S3Profile$1.call(S3Profile.java:158) at hudson.plugins.s3.S3Profile$1.call(S3Profile.java:155) at hudson.plugins.s3.S3Profile.repeat(S3Profile.java:258) ... 12 more

Can't quite see what's causing it to fail.

Ran into a similar issue, when attempting to set 'Cache control' headers during publishing to S3, and eventually figured out that the userMetadata parameter had to be set twice (going by the Jenkins pipeline syntax editor). Oddly enough, it worked.

Working pipeline step is as follows: 

step([$class: 'S3BucketPublisher',
 consoleLogLevel: 'INFO',
 dontWaitForConcurrentBuildCompletion: false,
 entries: [[
 bucket: 'example.com',
 excludedFile: '',
 flatten: false,
 gzipFiles: false,
 keepForever: false,
 managedArtifacts: false,
 noUploadOnFailure: true,
 selectedRegion: 'ap-south-1',
 showDirectlyInBrowser: false,
 sourceFile: 'dist/**/*',
 storageClass: 'STANDARD',
 uploadFromSlave: true,
 useServerSideEncryption: false,
 userMetadata: [[key: 'Cache-Control', value: 'max-age=86400']]
 ]],
 profileName: 's3deployer',
 pluginFailureResultConstraint: 'FAILURE',
 userMetadata: [[key: 'Cache-Control', value: 'max-age=86400']]
 ])