Singapore Flyer

Wednesday, February 5, 2020

Error: CERT_UNTRUSTED in npm install

In ubuntu18, when I tired npm install, I am getting the following error


Fix : Remove the current nodejs and npm and install the latest nodejs and npm version.
This will fix the error

Monday, March 18, 2019

How to find files which do not have a string

In Linux, i have a folder which has 1K files. I need to know which all files doesn't have a string which I need. In this example, I need to know which all files doesn't have the string/word - apps

cd /path/to/folder
grep -rIL apps

This will list the files which doesn't have the string "apps" in it 

Thursday, March 14, 2019

CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource

Scenario :

My UI is developed in OJet. It accept some input fields from browser and these inputs needs to be passed as a parameter a shell script.

My Ojet application is running on port 80 and I have a nodejs server running on port 8000. From Ojet web UI when a user clicked on button, it will call an api POST request to my nodejs application and the user input fields are as parameters.

How to solve this error

CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Open your nodejs server.js file (In my case) . Add the following res.header fileds.

app.use(function(req, res, next) {
  res.header("Access-Control-Allow-Origin", "*");
  res.header("Access-Control-Allow-Headers", "Origin, X-Requested-With, Content-Type, Accept");

It fixed my issue.

Monday, March 11, 2019

Oracle API Gateway Node installation error on join action

I am trying to install a gateway node setup using a OCI-classic. Though i could complete the action install,configure & start in sequence, i am unable to finish the JOIN action. I am doing the steps in sequence. Below is the snip of the logs that i have got from registerNode.log (full logs attached as a image): 

DEBUG:root:Performing dev env SSL related workarounds
ERROR:root:Error: Unable to add grant , reason = ['Traceback (most recent call last):\n', '  File "", line 2246, in addGrantToUser\n    resp = urllib2.urlopen(request,data = addGrantJson,context=sslContext)\n', '  File "", line 154, in urlopen\n', '  File "", line 429, in open\n', '  File "", line 447, in _open\n', '  File "", line 407, in _call_chain\n', '  File "", line 1241, in https_open\n', '  File "", line 1201, in do_open\n', '  File "", line 1121, in getresponse\n', '  File "", line 438, in begin\n', '  File "", line 402, in _read_status\n', "BadStatusLine: ''\n"]
WARNING:root:Gateway runtime user could not be given the requisite node service account grants
INFO:status:complete action: join isSuccess: failed detail: {"status": "NOT_JOINED"}
ERROR:main:Action join has failed. Detail: {"status": "NOT_JOINED"}
INFO:main:Gateway join complete.Status = NOT_JOINED.Please check log files for more details

I am pretty sure that i have the entered Gateway runtime user in the node service account grants of the logical gateway itself.

The gatewayExecutionMode is Development. And, i have checked the status of the gateway node but it looks alright. I have attached the logs as image.  I doubt this is related to network. But, could someone please give me a clarity on this ? 

Solution : 
Check your MTU setting for the network interface of the gateway node machine. It should be 1500. For more details, how to set the MTU to 1500 (