How to get on-prem IS to upload a file into Azure 'Blob' storage

Sonam_Chauhan · January 14, 2022, 7:44am

Hi – I need help having Integration Server 10.1 upload a simple CSV data file to an Azure ‘Blob’ storage container.

That is, I need to make IS upload file.csv to https://<storage-account-name>.blob.core.windows.net/<container-name>. The IS version is 10.1 on-prem (extended support).

I thought it would be easy, but Microsoft offers these two options to upload files to Azure blob storage:

A horribly complicated REST API
It comes complete with requirements for custom headers with hashed and digitally signed content – see here for a simple script-based query. This seems unworkable.
The uploading client (IS 10.1) uses a Microsoft-authored Java package to upload files
For this, Microsoft asks we add these entries to pom.xml. I know pom.xml is par for the course for Java ninjas. However, to a webMethods dev like me it’s an Alice in Wonderland-level rabbit hole.

I favor option #2. So I tried something like this:

Identify and download a suitable JAR (is the one below suitable - I have no idea; I just went clicking around?).
https://repo1.maven.org/maven2/com/azure/azure-storage-blob/12.14.2/azure-storage-blob-12.14.2.jar
Add it to a package’s /code/jars folder (I also added it to /code/classes)
In the new package, add Java code like the following
(adapted from this Microsoft sample code)

import com.azure.storage.blob.*;
/* Create a new BlobServiceClient using account key */
BlobServiceClient blobServiceClient = new BlobServiceClientBuilder()
    .endpoint("https://<storage-account-name>.blob.core.windows.net")
    .credential (new StorageSharedKeyCredential("<accountName>", "<accountKey>") )
    .buildClient();

/* Create a new container client */
try {
    containerClient = blobServiceClient.createBlobContainer("<container-name>");
} catch (BlobStorageException ex) {
    // The container may already exist, so don't throw an error
    if (!ex.getErrorCode().equals(BlobErrorCode.CONTAINER_ALREADY_EXISTS)) {
        throw ex;
    }
}

/* Upload the file to the container */
BlobClient blobClient = containerClient.getBlobClient("file.csv");
blobClient.uploadFromFile("file.csv");

Unfortunately, the sample Java code fails to compile – I get this error:

Has anyone got IS to upload to Azure ‘Blob’ storage before?

Any thoughts on the error? Does my approach above sound reasonable?

Other options:

I heard of some ‘Azure adapter’ for IS, but my site’s not licensed for it (and it may not be available for 10.1)
Microsoft has introduced an SFTP transfer option for Azure storage. That would be ideal, but it’s beta and only new subscriptions can use it (so my company’s containers cannot enable SFTP)

Update

Rakesh described his OAuth/REST API-based solution (accepted solution below)
An Azure Java API-based solution is also working, as documented here: How to get on-prem IS to upload a file into Azure 'Blob' storage - #12 by Sonam_Chauhan

Rakesh_Kumar3 · January 14, 2022, 2:29pm

Hi Sonam ,

You can use Azure Storage APIs to upload data to Azure Storage from On-Premise .

For Azure Storage API , you need to handle the Authentication properly . There are multiple approach for authentication . For example in our scenario , we are using Authorize with Azure Active Directory via OAuth 2.0 tokens .

We have a registered App on Azure AD associated with a user , which we use to get token . The App has been provided required access on Azure storage to do read/write operations .

If you do not want to use Azure Storage APIs , you can map Azure Storage as SMB/CIFS share and then write files to it .

To achieve above OAuth 2.0 based authentication , we have used flow services with pub.client:http calls .

We are using both the above approaches to read/write files to Azure Storage and working fine for us .

Let me know if further details required .

Sonam_Chauhan · January 14, 2022, 2:38pm

Progress (well, got it compiling at least)!

Initially, I’d downloaded azure-storage-blob-12.14.2.jar. Later, I found its webpage lists four additional JAR package as dependencies. I downloaded these into the /code/jars folder and reloaded the package:

azure-core-1.22.0.jar 
azure-core-http-netty-1.11.2.jar 
azure-storage-common-12.14.1.jar  
azure-storage-internal-avro-12.1.2.jar

…then kept fixing compile errors until I got this code to compile:

import com.azure.storage.blob.models.*;
import com.azure.storage.*;
import com.azure.storage.common.*;
import com.azure.core.exception.*;

...

		/* Create a new BlobServiceClient with a Shared Key */
		BlobServiceClient blobServiceClient = new BlobServiceClientBuilder()
		    .endpoint("https://<storage-account-name>.blob.core.windows.net")
		    .credential (new StorageSharedKeyCredential("<accountName>", "<accountKey>") )
		    .buildClient();    
		 
		BlobContainerClient containerClient =null;  
		/* Create a new container client */
		try {
		    containerClient = blobServiceClient.createBlobContainer("<container-name>");
		} catch (BlobStorageException ex) {
		    // The container may already exist, so don't throw an error
		    if (!ex.getErrorCode().equals(BlobErrorCode.CONTAINER_ALREADY_EXISTS)) {
		        throw ex;
		    }
		}
		
		/* Upload the file to the container */
		BlobClient blobClient = containerClient.getBlobClient("file.csv");
		blobClient.uploadFromFile("file.csv");

Next week I plan to progress further. One essential change I need is to make blobClient accept a stream as input.

Sonam_Chauhan · January 14, 2022, 2:59pm

Thanks Rakesh – you seem to have this well architected in your infrastructure. My company’s IS servers run on Linux. Does your IS run on Windows? Would that make a difference in approach?

I didn’t see any other option except the REST and Java APIs. When I checked out the REST API, it looked terribly convoluted (e.g., coding up the necessary content signing, etc). That’s why I went down the Java client route. I made some headway (see above) – I intend to find out next week if it actually works.

An SMB/CIFS share sounds like a good third option. Even if an SMB/CIFS share is not directly mounted on Linux, it can be exposed via FTP/SFTP.

Somehow this option never came up in discussions on my side. Looking at the link you share, this refers to ‘Azure Files’. This may be different from ‘Azure Blob storage’ , which is what I am dealing with.

Can Azure Blob storage be exposed over SMB/CIFS? This may not be possible, based on what I read in this link.

Thanks again for your input - it gives me a few things to think about…

Rakesh_Kumar3 · January 14, 2022, 3:52pm

Yes , our servers are on Linux Servers as well . Be it Windows or Linux it will not have any difference in approach .
In my view it’s better to use API , also via Java code as well you are going to do the same thing for e.g. passing same set of parameters as required in the API call.

If you go via the App registration approach on Azure AD , you can use it further for any other authentication/authorization request for Any Azure/Microsoft related services .

See below link for registering an app on Azure and getting OAuth authentication token .

The above link has section for Registering App on Azure AD
or

And use the Client Credentials based OAuth grant which is generally preferred to use for any Server to Server authentication .

Yes , via NFS (Network file system) , you can do it for Azure Blob storage as well .

[General Comment] CIFS shares can be directly mounted on Linux servers , we are using it since long for different integration requirements .

This approach should work as well , We try to avoid using Java service unless unavoidable and mostly depend on Flow services , APIs in our landscape .

Also , we have different Microsoft/Azure services in our environment so, we have built Azure OAuth common framework which we use across for authentication/authorization .

Sonam_Chauhan · January 14, 2022, 11:04pm

Thanks for your guidance Rakesh. Your approach, with its approved app and AD authentication, seem well integrated.

What concerns me about using the REST API is the complexity in constructing the special signature-based Authorization header that MS demands - here someone else built one for a simple query that just list objects in storage (no upload). This is a for simple GET - for a PUT, we’d hash and sign the payload too.

# Build the signature string
canonicalized_headers="${x_ms_date_h}\n${x_ms_version_h}"
canonicalized_resource="/${storage_account}/${container_name}"

string_to_sign="${request_method}\n\n\n\n\n\n\n\n\n\n\n\n${canonicalized_headers}\n${canonicalized_resource}\ncomp:list\nrestype:container"

# Decode the Base64 encoded access key, convert to Hex.
decoded_hex_key="$(echo -n $access_key | base64 -d -w0 | xxd -p -c256)"

# Create the HMAC signature for the Authorization header
signature=$(printf "$string_to_sign" | openssl dgst -sha256 -mac HMAC -macopt "hexkey:$decoded_hex_key" -binary |  base64 -w0)

authorization_header="Authorization: $authorization $storage_account:$signature"

I am curious: did you do something equivalent to the above steps in your custom Azure app? Are equivalent HMAC cryptography calls available in WmPublic?
Yes, CIFS and SMB should be mountable on Linux. But I doubt Azure Blob storage (which is an object store) exposes its content via CIFS/SMB (block-based storage) - I couldn’t find any documentation for this. I’d be happy to be wrong though.

Rakesh_Kumar3 · January 15, 2022, 3:46am

We didn’t use Shared Access Signature based authorization , but it’s possible .

App Registration step is a which is used as a mechanism to use the authentication and authorization provided by Azure AD Identity platform , other use cases are also there but for this scenario let’s concentrate on Authentication & Authorization.

So, we created a representational App on Azure AD for our webMethods servers , with which we can leverage OAuth features and connect to different Microsoft and Azure services seamlessly .

I have used OAuth 2.0 based authentication with client credentials grant , It’s a different authentication than Shared Access signature and it’s a very simple method. You need to call the Azure AD Oauth 2.0 token endpoint to get the authorization token and then use the token for Azure Storage API Call .

Step by Step which we have followed .

Register Application on Azure AD
Provide the App access on the Azure Storage account , according to the operations you will be performing
Call OAuth 2.0 token endpoint to get the OAuth 2.0 token
Use OAuth token to call the Azure Storage API and do the required operation .

Token API Call .

Once you get the token , you can use it for Azure Storage API Call
Azure Storage API Call [Token from above API call is passed as Bearer Authorization token]

Azure Blob supports NFS , which you can use to mount on Linux servers . link below

Sonam_Chauhan · January 15, 2022, 5:39am

Thank you @Rakesh_Kumar3 - This is an excellent illustration and you have been very kind in documenting it so thoroughly.

Summarising my understanding, your technique requires the organisation’s AD admins initially register the integration platform with its Azure AD identity provider. Then at runtime, IS first obtains an OAuth 2.0 token (using its registered identity), and uses the token as ‘Bearer’ Authorization (which simply passes the token) to make blob storage calls.

Thanks also for the NFS3 link!

I plan to discuss your approach with my AD admins next week. I also plan to give my Java code a push to see if it works, then update back here.

Thanks again!

Rakesh_Kumar3 · January 15, 2022, 6:22am

Ok sure , thanks .

keep us posted , how it goes .

Me/Someone else from the community will be happy to help.

Sonam_Chauhan · January 17, 2022, 4:34am

Update: while Rakesh’s answer seems like the correct way to do things, I’m proceeding with the Java service I wrote for now. It compiles, but won’t run because the five azure-*.jar JAR files I downloaded into <package>/code/jars are not enough. Here, the code has indirect dependencies on packages like org.reactivestreams.*.

Could not run 'deliverDataToAzureBlobStorageService'
java.lang.reflect.InvocationTargetException: org/reactivestreams/Publish

So it’s not enough for me to go poking Maven Central and manually noting dependencies is not enough - I need to download and use Maven to consolidate all JARs necessary for Azure blob storage operations.

Sonam_Chauhan · January 17, 2022, 7:14am

(I’ve made this a new forum question)

I’ve managed to get all required JARs (39 of them!) into the package code/jars folder. But the Java service now fails with the dependency error below. Any ideas how to resolve?

Basically, I need to compel my Java code (and classes it calls) to use the newly packaged Jackson version 2.x JARs (instead of Jackson version 1.x JARs packaged by IS).

Could not run 'deliverDataToAzureBlobStorageService'
java.lang.reflect.InvocationTargetException: Package versions: jackson-annotations=2.10.1, jackson-core=2.10.1, jackson-databind=2.10.1, jackson-dataformat-xml=unknown, jackson-datatype-jsr310=unknown, azure-core=1.22.0, Troubleshooting version conflicts: https://aka.ms/azsdk/java/dependency/troubleshoot

Below, I outlined the steps taken to package up the JARs.



1. #Install Maven and check version
#Adapted from https://tecadmin.net/install-apache-maven-on-fedora/

wget https://dlcdn.apache.org/maven/maven-3/3.8.4/binaries/apache-maven-3.8.4-bin.tar.gz
sudo tar xzf apache-maven-3.8.4-bin.tar.gz -C /opt
cd /opt && sudo ln -s apache-maven-3.8.4 maven
sudo vi /etc/profile.d/maven.sh
Add this content
--------------------------
export M2_HOME=/opt/maven
export PATH=${M2_HOME}/bin:${PATH}
--------------------------------
source /etc/profile.d/maven.sh
mvn -version


2. # Go to home folder, initialize Maven and have it generate a dummy pom.xml
#Adapted from https://maven.apache.org/guides/getting-started/maven-in-five-minutes.html

cd 
mvn archetype:generate -DgroupId=com.mycompany.app -DartifactId=my-app -DarchetypeArtifactId=maven-archetype-quickstart -DarchetypeVersion=1.4 -DinteractiveMode=false


3. #Configure Maven to download all required JARs for Azure Blob storage locally
#Adapted from https://technology.amis.nl/software-development/java/download-all-directly-and-indirectly-required-jar-files-using-maven-install-dependencycopy-dependencies/

cd my-app
vi pom.xml
Add the following to the dependencies section:

# Dependency adapted from: https://docs.microsoft.com/en-us/java/api/overview/azure/storage?view=azure-java-stable)
# Only the first dependency is taken. The current version is used 
#If not, you can expect a "Could not resolve dependencies"  error 
-----------------------
<dependency>
    <groupId>com.azure</groupId>
    <artifactId>azure-storage-blob</artifactId>
    <version>12.4.0</version>
</dependency>
----------------------------
mvn install dependency:copy-dependencies


4. #Maven now downloads 39 JAR files to the 'my-app/target/dependency/' folder
# Move these into the IS <package>/code/jars folder.
#Reload your package
cd /home/<user>/my-app/target/dependency/

5. #At this point, running the service gets past the missing JAR errors, but returns this new dependency error below.
-----------------------------
java.lang.reflect.InvocationTargetException: Package versions: jackson-annotations=2.10.1, jackson-core=2.10.1, jackson-databind=2.10.1, jackson-dataformat-xml=unknown, jackson-datatype-jsr310=unknown, azure-core=1.22.0, Troubleshooting version conflicts: https://aka.ms/azsdk/java/dependency/troubleshoot
-----------------------------

#This is probably because IS 10.1 shows the 1.x version of the Jackson JAR loaded on it's 'About' page, while the JAR version used by Azure is 2.x:
# /opt/SoftwareAG101/IntegrationServer/lib/jars/jackson-coreutils-1.8.jar

Sonam_Chauhan · January 21, 2022, 1:30pm

I’ve finally managed to get the Java-based solution running.

Here’s the code. Note, a large number of dependencies need to be installed in the package’s code/jars folder. This is documented further below.

import com.wm.data.*;
import com.wm.util.Values;
import com.wm.app.b2b.server.Service;
import com.wm.app.b2b.server.ServiceException;
import com.azure.storage.blob.*;
import com.azure.storage.blob.models.*;
import com.azure.storage.*;
import com.azure.storage.common.*;
import com.azure.core.exception.*;
import com.azure.core.util.BinaryData;

public final class deliverDataToAzureBlobStorageService_SVC

{

	/** 
	 * The primary method for the Java service
	 *
	 * @param pipeline
	 *            The IData pipeline
	 * @throws ServiceException
	 */
	public static final void deliverDataToAzureBlobStorageService(IData pipeline) throws ServiceException {
		// pipeline
		IDataCursor pipelineCursor = pipeline.getCursor();
			Object	sourceBytes = IDataUtil.get( pipelineCursor, "sourceBytes" );
			String	sourceFilename = IDataUtil.getString( pipelineCursor, "sourceFilename" );
			String	destinationBlobName = IDataUtil.getString( pipelineCursor, "destinationBlobName" );
			String	accountName = IDataUtil.getString( pipelineCursor, "accountName" );
			String	accountSharedAccessSignature = IDataUtil.getString( pipelineCursor, "accountSharedAccessSignature" );
			String	destinationContainerName  = IDataUtil.getString( pipelineCursor, "destinationContainerName" );
			String	createContainer = IDataUtil.getString( pipelineCursor, "createContainer" );
		pipelineCursor.destroy();
		
		/* Input handling */
		//Check that either the binaryData or sourceFilename input was specified (binaryData has preference)
		BinaryData binaryData = null;
		if (sourceBytes != null ) {
			binaryData = BinaryData.fromBytes((byte[]) sourceBytes);
		} else {
			if (sourceFilename == null) {
				throw new ServiceException ("Error: sourceBytes and sourceFilename cannot both be null");
			}
		}
		// default createContainer to false
		if (createContainer == null ) createContainer = "false";  
		
		/* Authenticate and upload data */
		//Create a new BlobServiceClient with the input SAS token
		BlobServiceClient blobServiceClient = new BlobServiceClientBuilder()
		    .endpoint("https://"+accountName+".blob.core.windows.net")
		    .sasToken(accountSharedAccessSignature)
		    .buildClient();    
		 
		//Create new container client. Have it either create a container or attach to an existing container 	
		BlobContainerClient containerClient =null;  
		if (createContainer.equals("true")) {
			containerClient = blobServiceClient.createBlobContainer(destinationContainerName);
		} else {
			containerClient = blobServiceClient.getBlobContainerClient(destinationContainerName);
		}
		
		//Upload data to the container. If the sourceBytes input is available, data is sourced from that.    
		//If it is null, data is instead sourced from the sourceFilename input (representing a local file). 
		BlobClient blobClient = null;
		blobClient = containerClient.getBlobClient(destinationBlobName);
		if (binaryData == null ) {
			blobClient.uploadFromFile(sourceFilename);
		} else {
			blobClient.upload(binaryData);
		}
		
		// There is no output pipeline because the Microsoft BlobClient.upload* methods above do not return status.
		// The transfer is deemed successful if no exception was thrown running by this service.
			
	}

Here’s the documentation accompanying this service. The NOTES section documents how dependencies that need to be installed in the package’s code/jars folder (40 JAR files in all) are sourced.

INPUT
========
sourceBytes - Optional. A byte array with content to be uploaded to Azure Blob Storage service. Either this input, or the sourceFilename input must be provided. 
	If both are specified, the sourceBytes input is preferred. 
sourceFilename - Optional. Path to local file to be uploaded to Azure Blob Storage service. Either this input, or the sourceBytes inputs must be specified. 
	If both are specified, the sourceBytes input is preferred. 
destinationBlobName - The name of blob containing the source data that is to be created in the Azure Blob Storage service. 
accountName - The account name used to authenticate to the Azure Blob Storage service. 
accountSharedAccessSignature - The Shared Access Signature (SAS) token used to authenticate to the Azure Blob Storage service. 
	E.g., 'sp=asdfghj&st=2022-01-20T01:55:17Z&se=2024-01-20T09:55:17Z&sv=2020-08-04&sr=c&sig=asdfghj%2Basdfghjk%2Basdfghjk%3D'
destinationContainerName - The name of the Azure Blob Storage container where the blob will be created. This can include a path within the container. 
	E.g. 'inbound/webmethods'
createContainer - true/false value (default is false). Whether the destination storage container must be created before blob upload is attempted. 


OUTPUT
=======
(None)


PROCESS
=======
This service accepts input data and uploads it to an Azure Blob Storage container. It does so using Azure Blob Storage Java library. It uses a Shared Access Signature 
(SAS) token to authenticate to the Azure Blob Storage service. For details, please see notes. 

If the sourceBytes input is specified, data is preferentially sourced from this input. Otherwise, data is sourced from the sourceFilename input (representing a local file).
	
This service returns no output. This is because the Microsoft Azure Blob Storage API BlobClient.upload* methods do not return status. Instead, data transfer is deemed 
succeessful if no exception was thrown when running by this service.
			

NOTES
========
1. Installing Azure Blob Storage Java Libraries
This Java service uses external open-source Azure Blob Storage Java libraries published by Microsoft, and dependent other related open-source code. 
For this service to work, several external JARs (40 of them!) must be sourced and installed into the package's code/jars folder. You can use the Maven 
build management application for this. Follow the procedure below. 

1.1. Install Maven 
(Adapted from https://tecadmin.net/install-apache-maven-on-fedora/ )
--------------------------------------------------------------------------------------------------
wget https://dlcdn.apache.org/maven/maven-3/3.8.4/binaries/apache-maven-3.8.4-bin.tar.gz
sudo tar xzf apache-maven-3.8.4-bin.tar.gz -C /opt
cd /opt && sudo ln -s apache-maven-3.8.4 maven
sudo vi /etc/profile.d/maven.sh
# Add this content:
_______________________________________________
export M2_HOME=/opt/maven
export PATH=${M2_HOME}/bin:${PATH}
_______________________________________________
source /etc/profile.d/maven.sh
mvn -version
--------------------------------------------------------------------------------------------------

1.2. Initialize Maven and generate a dummy project
(Adapted from https://maven.apache.org/guides/getting-started/maven-in-five-minutes.html )
Carry out the following steps in a <work-folder> 
--------------------------------------------------------------------------------------------------
cd <work-folder>
mvn archetype:generate -DgroupId=com.mycompany.app -DartifactId=my-app -DarchetypeArtifactId=maven-archetype-quickstart -DarchetypeVersion=1.4 -DinteractiveMode=false
--------------------------------------------------------------------------------------------------

1.3. Configure Maven to download all required JARs for Azure Blob storage locally
(Adapted from https://technology.amis.nl/software-development/java/download-all-directly-and-indirectly-required-jar-files-using-maven-install-dependencycopy-dependencies/ )
The dependency list was adapted from: https://docs.microsoft.com/en-us/java/api/overview/azure/storage?view=azure-java-stable
Only the 'azure-storage-blob' dependency was chosen. The current version is used (otherwise you can expect a "Could not resolve dependencies"  error). 
--------------------------------------------------------------------------------------------------
cd my-app
vi pom.xml
# Add the following to the dependencies section:
_______________________________________________
<dependency>
    <groupId>com.azure</groupId>
    <artifactId>azure-storage-blob</artifactId>
    <version>12.4.0</version>
</dependency>
_______________________________________________
--------------------------------------------------------------------------------------------------

1.4. Download all JARs 
Run this maven command in <work-folder> 
--------------------------------------------------------------------------------------------------
mvn install dependency:copy-dependencies
--------------------------------------------------------------------------------------------------
Maven now downloads 39 JAR files to the 'my-app/target/dependency/' subfolder

1.5.  Move the 39 downloaded JAR files into the IS <package>/code/jars folder.
--------------------------------------------------------------------------------------------------
cd <work-folder>/my-app/target/dependency/
...
cp *.jar <IS>/<package>/code/jars
--------------------------------------------------------------------------------------------------
1.6. Reload your package
Reload the package and test the service. At this point, running the service in IS 10.1 gets past errors about missing JARs but returns this new dependency error below.
--------------------------------------------------------------------------------------------------
java.lang.reflect.InvocationTargetException: Package versions: jackson-annotations=2.10.1, jackson-core=2.10.1, jackson-databind=2.10.1, jackson-dataformat-xml=unknown, jackson-datatype-jsr310=unknown, azure-core=1.22.0, Troubleshooting version conflicts: https://aka.ms/azsdk/java/dependency/troubleshoot
--------------------------------------------------------------------------------------------------
This is probably because IS 10.1 shows the 1.x version of the Jackson JAR loaded on it's 'About' page. 
--------------------------------------------------------------------------------------------------
 <SAG-10.1-folder>/IntegrationServer/lib/jars/jackson-coreutils-1.8.jar
--------------------------------------------------------------------------------------------------
However, the JAR version used by Azure is 2.x

1.7 Configure webMethods package to prioritise local JARs
Basically, the package's Java code (and the classes that it calls) needs to be persuaded to use the newly packaged Jackson version 2.x JARs 
(instead of the Jackson version 1.x JARs packaged by IS). For this, edit the manifest.v3 file of the package to use the package class loader, as 
described in documentation below 
-------------------------------------------------------------------------------------------------
[From 'webMethods Integration Server Administrator’s Guide Version 10.1' page 46]

A package's manifest.v3 file controls a number of characteristics of a package,
including whether the package's class loader defers to its parent class loader. The
default is to defer to the parent class loader. However, Integration Server will use the
package class loader instead, if the following is specified in the manifest.v3 file:
____________________________________________________________________
<value name='classloader'>package</value>
____________________________________________________________________
If a package uses its own class loader, the jar files containing the classes you
want to make available must be in the Integration Server_directory\instances
\instance_name \packages\packageName \code\jars directory.
-------------------------------------------------------------------------------------------------

1.8. Workaround circular dependency in slf4j packages.
At this point, running the service returns the following error:
--------------------------------------------------------------------------------------------------
Could not run 'deliverDataToAzureBlobStorageService'
java.lang.reflect.InvocationTargetException: loader constraint violation: when resolving method "org.slf4j.impl.StaticLoggerBinder.getLoggerFactory()Lorg/slf4j/ILoggerFactory;" 
the class loader (instance of com/wm/app/b2b/server/PackageClassLoader) of the current class, org/slf4j/LoggerFactory, 
and the class loader (instance of java/net/URLClassLoader) for the method's defining class, org/slf4j/impl/StaticLoggerBinder, have different Class objects for the type org/slf4j/ILoggerFactory used in the signature
--------------------------------------------------------------------------------------------------

Thankfully, I could wing it after coming across this article: 
	https://documentation.tribefire.com/tribefire.cortex.documentation/concepts-doc/features/tribefire-modules/troubleshooting/slf4j-api-linkage-error.html
This article suggested installing slf4j-jdk14-1.7.32.jar. This is an unlisted dependency that accompanies the slf4j-api-1.7.32 JAR 
dependency that Maven had automatically downloaded. Adding this JAR resolves a sort of crazy circular dependency in the slf4j package.

1.9 Acknowledgements
I was assisted greatly by these two forum posts. The first post suggests a possibly better architecture for this solution. The second suggested 
the workaround in point 1.8 above.
--------------------------------------------------------------------------------------------------
https://tech.forums.softwareag.com/t/how-to-get-on-prem-is-to-upload-a-file-into-azure-blob-storage/254459/10
https://tech.forums.softwareag.com/t/can-is-java-service-use-a-different-version-jar-than-one-provided-by-is/254533
--------------------------------------------------------------------------------------------------


2. SAS Token Expiry
The 'Shared Access Signature' (SAS) input to this service is a token that enable it to exchange data with Azure Blob Storage infrastructure. A SAS token has a defined lifetime. 
When it expires, integration breaks. To prevent this, a new token must generated and configured on both systems (Azure Blob Storage and webMethods integration) prior
to the expiry date.

For convenience, an SAS token can be made to expire far in the future (possibly as far as the year 9999). The reasons are:  
	1. Instead of the sensitive Storage Shared Key credential, the integration uses a SAS token signed by the key. The SAS token is designed to be a limited-access artifact. 
	2. Authorization rights granted to the SAS token used by this service may be revoked without affecting other applications. 
	3. System-to-system integration with Azure Blob Storage can operate indefinitely without an absolute future date before which the token must change.

Nagendra_Prasad · January 21, 2022, 1:46pm

@toni.petrov , The previous post has complete details on how to get a file onto Azure Blob storage , would it be possible to extract the post into a KB article, It is sure to help somebody.

-Nagendra

toni.petrov · January 21, 2022, 3:23pm

Thanks Nagendra!
@Sonam_Chauhan would you mind creating a new topic with that info only as Nagendra suggested? I’ll then move it to the Knowledge base section.

Sonam_Chauhan · January 21, 2022, 4:14pm

@toni.petrov - Happy to help, but unsure how I can. There are two solutions:

Rakesh described an OAuth/REST API-based solution (accepted solution) in post #7 How to get on-prem IS to upload a file into Azure 'Blob' storage - #7 by Rakesh_Kumar3
An Azure Java API-based solution is documented in post #12 How to get on-prem IS to upload a file into Azure ‘Blob’ storage - #12 by Sonam_Chauhan

reamon · January 21, 2022, 5:36pm

Would you be able share the rationale? I’m a bit surprised at this choice.

toni.petrov · January 21, 2022, 5:59pm

Yes, @Nagendra_Prasad 's suggestion was to recreate post #12 How to get on-prem IS to upload a file into Azure ‘Blob’ storage - #12 by Sonam_Chauhan as Sonam understood it
I think both solutions are very useful depending on the use case, but since Rakesh’s answer was selected as Answer it will show up first here.

Btw, after this is done I’ll remove that part of the discussion as it got off-topic.

Sonam_Chauhan · January 23, 2022, 12:20pm

The rebuke of the wise! Thanks Rob.

Look - you’re probably right: Rakesh’s approach seems architecturally more modern and may be better overall. My approach may boil down to taste - it is reminiscent of how old-style ‘adapters’ work, complete with 40 JAR files in a package code/jars folder.

Another excuse: my Microsoft admin resource was busy, so I plugged away using what I obtained from him: a Shared Access Signature (‘SAS’) token and access URL.

Also another thing which may or may not be valid:

At runtime, Rakesh’s REST approach does this:

POST login.microsoft.com... to get an OAuth token
PUT <account>.blob.core.windows.net... using the OAuth token in a Bearer Authorization token

My approach:

Java code uses stored token (‘SAS’ token) to execute operations on <account>.blob.core.windows.net

Now both options may operate the same way behind the scenes. But from my (limited) perspective, the second approach uses one less moving part (no accessing login.microsoft.com). It also sidesteps concerns about OAuth token lifetime and renewal (but of course, a new OAuth token per operation may be perfectly feasible)

reamon · January 24, 2022, 4:27pm

True, but a entire pile of JARs and a version dependency that may come back to bite you in the future.

Everything is a trade off. Glad you were able to get your solution working–which is the main thing that counts.

Sonam_Chauhan · January 24, 2022, 10:29pm

Yes - true: 40 JARs to upload a file! Even the SAP adapter uses 3 JARs. Makes me appreciate terms like ‘dependency bloat’ Hopefully, with JARs isolated in their own package, it will be many upgrade cycles before SAG, Java (or Microsoft) have a problem with the codebase.

Out of curiosity, I went googling and found this paper: “We study the evolution and impact of bloated dependencies in a single software ecosystem: Java/Maven”