Homelab, Linux, JS & ABAP (~˘▾˘)~
 

Tag: BTP

BTP, CAP

[BTP] Get access token for specific tenant in a multitenant scenario using http rest client

 , , , , , , ,

https://docs.cloudfoundry.org/api/uaa/version/4.6.0/index.html#password-grant

01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
# url from XSUAA Service Key, but replace in the url the provider subdomain with the consumer subdomain (the tenant you want to call)
@xsuaaUrl = {{$dotenv xsuaaUrl}}
# clientid from XSUAA Service Key
@xsuaaClientId = {{$dotenv xsuaaClientId}}
# clientsecret from XSUAA Service Key
@xsuaaClientSecret = {{$dotenv xsuaaClientSecret}}
 
@username = {{$dotenv btp_username}}
@password = {{$dotenv btp_password}}
 
### Get Access Token for Cloud Foundry using Password Grant with BTP default IdP
# @name getXsuaaToken
POST {{xsuaaUrl}}/oauth/token
Accept: application/json
Authorization: Basic {{xsuaaClientId}}:{{xsuaaClientSecret}}
Content-Type: application/x-www-form-urlencoded
 
grant_type=password
&username={{username}}
&password={{password}}
&response_type=token
 
### Store access token
@access_token = {{getXsuaaToken.response.body.$.access_token}}
CAP

[CAP] Multitenant Job Scheduler – Request timeout after 15 seconds

 , , , , , ,

For Jobs running longer than 15 seconds, you have to manually inform the Job Scheduler if your operation succeeded or not. Else, your job will only stay in status COMPLETED/UNKNOWN due to the timeout.

Informing the Job Scheduler about your succeeded operation can be done vie REST API Endpoint Update Job Run Log. You can read more about Long-Running (Async) Jobs here. I therefore wrote a function named updateJobStatus, which I call at the end of every long-running endpoint. It checks if the endpoint is called manually or via Job Scheduler service and updates the Job Run Log using the @sap/jobs-client if required.

01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
const cds = require('@sap/cds')
const LOG = cds.log('JobService')
const xsenv = require("@sap/xsenv")
const JobSchedulerClient = require("@sap/jobs-client")
 
async function fetchAccessToken(url, creds) {
    const response = await fetch(`${url}/oauth/token`, {
        method: 'POST',
        body: 'grant_type=client_credentials&client_id=' + creds.uaa.clientid + '&client_secret=' + creds.uaa.clientsecret,
        headers: {
            'Content-Type': 'application/x-www-form-urlencoded'
        }
    })
    return await response.json()
}
 
async function getJobscheduler(req) {
    xsenv.loadEnv()
    const services = xsenv.getServices({
        jobscheduler: { tags: "jobscheduler" }
    })
    if (!services.jobscheduler) req.reject("no jobscheduler service instance found")
 
    const subdomain = (process.env.NODE_ENV === 'production') ? req.http.req.authInfo.getSubdomain() : 'customer1' // workaround for local testing
    const domain = `https://${subdomain}.${services.jobscheduler.uaa.uaadomain}`
    const token = await fetchAccessToken(domain, services.jobscheduler)
 
    const options = {
        baseURL: services.jobscheduler.url,
        token: token.access_token
    }
    return new JobSchedulerClient.Scheduler(options)
}
 
async function updateJobStatus(req) {
    const jobId = req.headers['x-sap-job-id']
    const scheduleId = req.headers['x-sap-job-schedule-id']
    const runId = req.headers['x-sap-job-run-id']
 
    if (!jobId || !scheduleId || !runId) return
    LOG.info('Endpoint is called via Job Scheduler')
 
    const scheduler = await getJobscheduler(req)
 
    const payload = {
        jobId: jobId,
        scheduleId: scheduleId,
        runId: runId,
        data: { success: true, message: 'The endpoint has successfully executed the long-running job' }
    }
 
    scheduler.updateJobRunLog(payload, function (err, result) {
        if (err) return LOG.error('Error updating run log: %s', err)
        //Run log updated successfully
        LOG.info('Run log updated successfully')
    })
}
 
module.exports = {
  updateJobStatus
}
CAP

[CAP] Multitenant Job Scheduler – Fixing Scope issue

 , , , , , , , , , , , , ,

When I was integrating the Job Scheduler service into my Multitenant Application, I ran into the following JWT Token issue, when the Job Scheduler was calling my CAP action. Means the job creation was already working fine and was also displaying the right tenant for my job, but the Job Scheduler was not able to successfully call the given endpoint. This is the error I got in the logs:

1
2
3
4
5
6
7
Error: Jwt token with audience: [
'sb-a1e9d3b8-2bee-47db-xxxx-07e5a54aec1e!b180208|sap-jobscheduler!b3',
'uaa'
] is not issued for these clientIds: [
'sb-MyApp-mtdev-App!t180208',
'MyAp-mtdev-App!t180208'
].

After reading some of the great blogs from Carlos Roggan, I noticed that I forgot to grant the Job Scheduler the necessary authority to actual call my CAP action. So I added the following lines to the xs-security.json file

1
2
3
4
5
6
7
{
  "name": "$XSAPPNAME.jobscheduler",
  "description": "Scope for Job Scheduler",
  "grant-as-authority-to-apps": [
    "$XSSERVICENAME(job-scheduler)"
  ]
}

and also annotated my CAP action using the new scope @(requires: ['jobscheduler']).

I redeployed everything, but the issue still persists. 🙁

Turned out, for the standard plan, tokens are cached in Job Scheduler up to 12 hours.

https://help.sap.com/docs/job-scheduling/sap-job-scheduling-service/secure-access?locale=en-US

After waiting 12 hours, the endpoint was successfully called by the Job Scheduler. 🙂

CAP

[CAP] Get service and approuter URLs of your running CAP application in a service handler

 , , , , , , , , , , ,

In your mta.yaml you can define environment variables, which are filled during deployment. They can be filled with MTA Development and Deployment Parameters. Click here for an overview.

To get the URL of your deployed CAP service, simply use the ${default-url} parameter and pass the value to a variable below the properties attribute, e.g. SRV_URL. The approuter has to provide its default-url, which can then be used in the service for a variable, e.g. APPROUTER_URL.

01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
#####################################################################################################################
# Approuter
#####################################################################################################################
- name: approuter
  type: approuter.nodejs
  path: app/approuter
  provides:
    - name: app-api
      properties:
        app-url: ${default-url}   # <---------------------------- provides approuter url
        app-uri: ${default-uri}   # <---------------------------- provides approuter uri/hostname
        app-protocol: ${protocol} # <---------------------------- provides approuter protocol
 
#####################################################################################################################
# Business Service Module
#####################################################################################################################
- name: mySrv
  type: nodejs
  path: gen/srv
  requires:
    - name: app-api # <---------------------------------------- required to access the provided variables of the approuter
  properties:
    SRV_URL: ${default-url}
    APPROUTER_URL: ~{app-api/app-url}
    SUBSCRIPTION_URL: ~{app-api/app-protocol}://\${tenant_subdomain}-~{app-api/app-uri}

After deployment, you can now access the URL via process.env.SRV_URL in a service handler. During development, simply use the .env file to provide the SRV_URL value.

You can check all the variables via the BTP Cockpit: Subaccount → Space → Select application → User-Provided Variables

CAP

[CAP] Approuter – Increase session lifetime

 , , , , ,

To increase the session lifetime, simply increase the sessionTimeout property in the xs-app.json of your approuter.

https://www.npmjs.com/package/@sap/approuter#xs-appjson-configuration-file

xs-app.json

1
2
3
4
5
6
7
8
9
{
  "welcomeFile": "index.html",
  "authenticationMethod": "route",
  "logout": {
    "logoutEndpoint": "/do/logout"
  },
  "sessionTimeout": 60,
  "routes": []
}

CAP

[CAP] Posting form data to a destination using executeHttpRequest

 , , , , , , , ,
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
const { executeHttpRequest } = require('@sap-cloud-sdk/http-client')
const FormData = require('form-data')
 
try {
    //Create payload
    const form = new FormData()
    form.append('file', fileContent, {
        contentType: 'application/pdf'
        filename: 'test.pdf'
    })
 
    //Create headers
    const headers = {
        ...form.getHeaders(),
        'Content-Length': form.getLengthSync(),
    }
 
    //Send to Destination
    const response = await executeHttpRequest(
        { destinationName: 'TESTINATION' },
        {
            method: 'POST',
            url: 'myApiPath',
            headers: headers,
            data: form,
            responseType: 'arraybuffer' // if you need the response data as buffer to prevent UTF-8 encoding
        }
    )
    console.log({response})
} catch (error) {
    console.error(error.message)
}