Sending GET request to API endpoint issues

Ignition
1

I am currently working on a project to get certain values from an API and use the values to make and update tags every few seconds. My problem is that I have tried everything to send a get request to the API, but I cannot get any data from it. From troubleshooting, I think the problem has to do with the URL of the API. The common errors I have gotten are Invalid URL - no protocol, Unable to GET -URL, and a status code of 302 when I need 200. I will post my code below. Any suggestions or help is welcome. My code is relatively incomplete until I can properly read the json data to write to tags.

import system

# API for KE2Evap
def getKE2EvapAPI():
    client = system.net.httpClient()
    url = "http://URL-IPaddress/api/Status"
    response = client.get(url)  # Make a request to the KE2 Evap OEM API
   
    if response.good:
        KE2APIValue = response.json  # Extract the value from the API response
        return KE2APIValue  # Return the API value
    else:
		print("Unable to get API value")
		return None
        

# Function for writing API value to tag
def writeValueToTag(tag_path, value):
    system.tag.write(tag_path, value)
      
	  
#Function to update tags with values from API
def updateTags():
    tag_mappings = {
        "[default]_types_/KE2 EVAP OEM API/FramewareVersion": "current", 	#test tag path and api argument key
     
        # Add more tag paths and their corresponding API argument keys as needed - added once program is working
    }

    KE2APIValue = getKE2EvapAPI()
    if KE2APIValue is not None: 	#if value != null
        for tag_path, api_key in tag_mappings.items():
            value_to_write = KE2APIValue.get(api_key) #get value from get request
            if value_to_write is not None:
                writeValueToTag(tag_path, value_to_write) #Function call to write values to tags
            else:
                print("API key not found in the API response for tag", tag_path)
    else:
        print("Failed to get KE2 Evap OEM API value")

updateTags()
2

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3

Thanks, should work now

4

Full error / stack trace or any additional info you have from the current revision of the code would be useful. Otherwise we're just guessing.

5

Full error:
Java Traceback:
Traceback (most recent call last):
File "", line 22, in
File "", line 6, in makeGetRequest
File "", line 6, in makeGetRequest
at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.send(JythonHttpClient.java:103)

at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.get(JythonHttpClient.java:306)

at jdk.internal.reflect.GeneratedMethodAccessor39.invoke(Unknown Source)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.base/java.lang.reflect.Method.invoke(Unknown Source)

java.io.IOException: java.io.IOException: Unable to GET https://172.19.108.30/api/Status

at org.python.core.Py.JavaError(Py.java:547)

at org.python.core.Py.JavaError(Py.java:538)

at org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:192)

at org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:208)

at org.python.core.PyObject.__call__(PyObject.java:477)

at org.python.core.PyObject.__call__(PyObject.java:481)

at org.python.core.PyMethod.__call__(PyMethod.java:141)

at org.python.pycode._pyx245.makeGetRequest$1(<input>:18)

at org.python.pycode._pyx245.call_function(<input>)

at org.python.core.PyTableCode.call(PyTableCode.java:173)

at org.python.core.PyBaseCode.call(PyBaseCode.java:134)

at org.python.core.PyFunction.__call__(PyFunction.java:416)

at org.python.pycode._pyx245.f$0(<input>:27)

at org.python.pycode._pyx245.call_function(<input>)

at org.python.core.PyTableCode.call(PyTableCode.java:173)

at org.python.core.PyCode.call(PyCode.java:18)

at org.python.core.Py.runCode(Py.java:1687)

at org.python.core.Py.exec(Py.java:1731)

at org.python.util.PythonInterpreter.exec(PythonInterpreter.java:277)

at org.python.util.InteractiveInterpreter.runcode(InteractiveInterpreter.java:130)

at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:611)

at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:599)

at java.desktop/javax.swing.SwingWorker$1.call(Unknown Source)

at java.base/java.util.concurrent.FutureTask.run(Unknown Source)

at java.desktop/javax.swing.SwingWorker.run(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

at java.base/java.lang.Thread.run(Unknown Source)

Caused by: java.io.IOException: Unable to GET https://172.19.108.30/api/Status

at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.send(JythonHttpClient.java:103)

at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.get(JythonHttpClient.java:306)

at jdk.internal.reflect.GeneratedMethodAccessor39.invoke(Unknown Source)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.base/java.lang.reflect.Method.invoke(Unknown Source)

at org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:190)

... 25 more

Caused by: java.io.IOException: No subject alternative names matching IP address 172.19.108.30 found

at java.net.http/jdk.internal.net.http.HttpClientImpl.send(Unknown Source)

at java.net.http/jdk.internal.net.http.HttpClientFacade.send(Unknown Source)

at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.send(JythonHttpClient.java:101)

... 30 more

Caused by: javax.net.ssl.SSLHandshakeException: No subject alternative names matching IP address 172.19.108.30 found

at java.base/sun.security.ssl.Alert.createSSLException(Unknown Source)

at java.base/sun.security.ssl.TransportContext.fatal(Unknown Source)

at java.base/sun.security.ssl.TransportContext.fatal(Unknown Source)

at java.base/sun.security.ssl.TransportContext.fatal(Unknown Source)

at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.checkServerCerts(Unknown Source)

at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.onCertificate(Unknown Source)

at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.consume(Unknown Source)

at java.base/sun.security.ssl.SSLHandshake.consume(Unknown Source)

at java.base/sun.security.ssl.HandshakeContext.dispatch(Unknown Source)

at java.base/sun.security.ssl.SSLEngineImpl$DelegatedTask$DelegatedAction.run(Unknown Source)

at java.base/sun.security.ssl.SSLEngineImpl$DelegatedTask$DelegatedAction.run(Unknown Source)

at java.base/java.security.AccessController.doPrivileged(Native Method)

at java.base/sun.security.ssl.SSLEngineImpl$DelegatedTask.run(Unknown Source)

at java.base/java.util.ArrayList.forEach(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate.lambda$executeTasks$3(Unknown Source)

at java.net.http/jdk.internal.net.http.HttpClientImpl$DelegatingExecutor.execute(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate.executeTasks(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate.doHandshake(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate$Reader.processData(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate$Reader$ReaderDownstreamPusher.run(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SequentialScheduler$SynchronizedRestartableTask.run(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SequentialScheduler$CompleteRestartableTask.run(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SequentialScheduler$SchedulableTask.run(Unknown Source)

... 3 more

Caused by: java.security.cert.CertificateException: No subject alternative names matching IP address 172.19.108.30 found

at java.base/sun.security.util.HostnameChecker.matchIP(Unknown Source)

at java.base/sun.security.util.HostnameChecker.match(Unknown Source)

at java.base/sun.security.ssl.X509TrustManagerImpl.checkIdentity(Unknown Source)

at java.base/sun.security.ssl.X509TrustManagerImpl.checkIdentity(Unknown Source)

at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)

at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)

... 22 more

Traceback (most recent call last):
File "", line 22, in
File "", line 6, in makeGetRequest
File "", line 6, in makeGetRequest
at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.send(JythonHttpClient.java:103)

at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.get(JythonHttpClient.java:306)

at jdk.internal.reflect.GeneratedMethodAccessor39.invoke(Unknown Source)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.base/java.lang.reflect.Method.invoke(Unknown Source)

java.io.IOException: java.io.IOException: Unable to GET https://172.19.108.30/api/Status

('Failed to make GET request:', 'get() argument url: expected String instance, PyObjectDerived found')
Failed to retrieve data from the API

('Failed to make GET request:', 'Invalid URL - no protocol: [https://172.19.108.30/api/Status]')
Failed to retrieve data from the API

('Failed to make GET request:', 'Invalid URL - no protocol: 172.19.108.30/api/Status')
Failed to retrieve data from the API

Java Traceback:
Traceback (most recent call last):
File "", line 23, in
File "", line 7, in makeGetRequest
File "", line 7, in makeGetRequest
at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.send(JythonHttpClient.java:103)

at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.get(JythonHttpClient.java:306)

at jdk.internal.reflect.GeneratedMethodAccessor39.invoke(Unknown Source)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.base/java.lang.reflect.Method.invoke(Unknown Source)

java.io.IOException: java.io.IOException: Unable to GET https://172.19.108.30/index.htm

at org.python.core.Py.JavaError(Py.java:547)

at org.python.core.Py.JavaError(Py.java:538)

at org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:192)

at org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:208)

at org.python.core.PyObject.__call__(PyObject.java:477)

at org.python.core.PyObject.__call__(PyObject.java:481)

at org.python.core.PyMethod.__call__(PyMethod.java:141)

at org.python.pycode._pyx253.makeGetRequest$1(<input>:19)

at org.python.pycode._pyx253.call_function(<input>)

at org.python.core.PyTableCode.call(PyTableCode.java:173)

at org.python.core.PyBaseCode.call(PyBaseCode.java:134)

at org.python.core.PyFunction.__call__(PyFunction.java:416)

at org.python.pycode._pyx253.f$0(<input>:28)

at org.python.pycode._pyx253.call_function(<input>)

at org.python.core.PyTableCode.call(PyTableCode.java:173)

at org.python.core.PyCode.call(PyCode.java:18)

at org.python.core.Py.runCode(Py.java:1687)

at org.python.core.Py.exec(Py.java:1731)

at org.python.util.PythonInterpreter.exec(PythonInterpreter.java:277)

at org.python.util.InteractiveInterpreter.runcode(InteractiveInterpreter.java:130)

at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:611)

at com.inductiveautomation.ignition.designer.gui.tools.jythonconsole.JythonConsole$ConsoleWorker.doInBackground(JythonConsole.java:599)

at java.desktop/javax.swing.SwingWorker$1.call(Unknown Source)

at java.base/java.util.concurrent.FutureTask.run(Unknown Source)

at java.desktop/javax.swing.SwingWorker.run(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)

at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)

at java.base/java.lang.Thread.run(Unknown Source)

Caused by: java.io.IOException: Unable to GET https://172.19.108.30/index.htm

at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.send(JythonHttpClient.java:103)

at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.get(JythonHttpClient.java:306)

at jdk.internal.reflect.GeneratedMethodAccessor39.invoke(Unknown Source)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.base/java.lang.reflect.Method.invoke(Unknown Source)

at org.python.core.PyReflectedFunction.__call__(PyReflectedFunction.java:190)

... 25 more

Caused by: java.io.IOException: No subject alternative names matching IP address 172.19.108.30 found

at java.net.http/jdk.internal.net.http.HttpClientImpl.send(Unknown Source)

at java.net.http/jdk.internal.net.http.HttpClientFacade.send(Unknown Source)

at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.send(JythonHttpClient.java:101)

... 30 more

Caused by: javax.net.ssl.SSLHandshakeException: No subject alternative names matching IP address 172.19.108.30 found

at java.base/sun.security.ssl.Alert.createSSLException(Unknown Source)

at java.base/sun.security.ssl.TransportContext.fatal(Unknown Source)

at java.base/sun.security.ssl.TransportContext.fatal(Unknown Source)

at java.base/sun.security.ssl.TransportContext.fatal(Unknown Source)

at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.checkServerCerts(Unknown Source)

at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.onCertificate(Unknown Source)

at java.base/sun.security.ssl.CertificateMessage$T12CertificateConsumer.consume(Unknown Source)

at java.base/sun.security.ssl.SSLHandshake.consume(Unknown Source)

at java.base/sun.security.ssl.HandshakeContext.dispatch(Unknown Source)

at java.base/sun.security.ssl.SSLEngineImpl$DelegatedTask$DelegatedAction.run(Unknown Source)

at java.base/sun.security.ssl.SSLEngineImpl$DelegatedTask$DelegatedAction.run(Unknown Source)

at java.base/java.security.AccessController.doPrivileged(Native Method)

at java.base/sun.security.ssl.SSLEngineImpl$DelegatedTask.run(Unknown Source)

at java.base/java.util.ArrayList.forEach(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate.lambda$executeTasks$3(Unknown Source)

at java.net.http/jdk.internal.net.http.HttpClientImpl$DelegatingExecutor.execute(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate.executeTasks(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate.doHandshake(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate$Reader.processData(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SSLFlowDelegate$Reader$ReaderDownstreamPusher.run(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SequentialScheduler$SynchronizedRestartableTask.run(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SequentialScheduler$CompleteRestartableTask.run(Unknown Source)

at java.net.http/jdk.internal.net.http.common.SequentialScheduler$SchedulableTask.run(Unknown Source)

... 3 more

Caused by: java.security.cert.CertificateException: No subject alternative names matching IP address 172.19.108.30 found

at java.base/sun.security.util.HostnameChecker.matchIP(Unknown Source)

at java.base/sun.security.util.HostnameChecker.match(Unknown Source)

at java.base/sun.security.ssl.X509TrustManagerImpl.checkIdentity(Unknown Source)

at java.base/sun.security.ssl.X509TrustManagerImpl.checkIdentity(Unknown Source)

at java.base/sun.security.ssl.X509TrustManagerImpl.checkTrusted(Unknown Source)

at java.base/sun.security.ssl.X509TrustManagerImpl.checkServerTrusted(Unknown Source)

... 22 more

Traceback (most recent call last):
File "", line 23, in
File "", line 7, in makeGetRequest
File "", line 7, in makeGetRequest
at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.send(JythonHttpClient.java:103)

at com.inductiveautomation.ignition.common.script.builtin.http.JythonHttpClient.get(JythonHttpClient.java:306)

at jdk.internal.reflect.GeneratedMethodAccessor39.invoke(Unknown Source)

at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source)

at java.base/java.lang.reflect.Method.invoke(Unknown Source)

java.io.IOException: java.io.IOException: Unable to GET https://172.19.108.30/index.htm

6

I think this is the key part.

You're trying to access this host by IP, but it has TLS/HTTPS enabled, and the IP isn't in the certificate.

7

Looks like your device is redirecting you to HTTPS instead of HTTP, but the device's encryption certificate only accepts access by name (not uncommon). Options:

  • Configure the device to allow HTTP.

  • Use a hostname instead of an IP address--one matching the device's own idea about its name.

  • Change the certificate in the device to include the IP address.

8

Thank you for all the help. I knew the device was redirecting to HTTPS and never knew what to do about it, but I will see who can help me change and configure the hostname and certificate, since I don't have those permissions.

9

I suppose there's one more option, but I don't recall how to do it:

  • Configure httpClient to ignore certificate problems.
10

You can pass bypass_cert_validation=True when constructing the httpClient.
https://docs.inductiveautomation.com/display/DOC81/system.net.httpClient