Network Capture to create HAR file in browser

Owned by Ole Kristian Aune (Unlicensed)
Last updated: Mar 16, 2023 by Steinar Line
3 min read

While troubleshooting certain issues, our support staff may ask for a network capture/log, in the form of a HAR-file. This is a detailed capture of requests and responses between your browser and Jira/Confluence/etc. server, enabling us to analyze what the browser is doing. 

Creating a HAR file

As a general guideline, we want the most minimal log possible, which still manages to capture the issue being investigated. This gives us fewer requests to analyze and also exposes less information about your instance. Do keep in mind that a HAR file gives us access to all request and response activity, including:

  • Submitted form data, including passwords, if you visit a login form. 

  • The contents of the pages you visit. For example, our support staff could read a Confluence article visited during the test. 

  • Session cookies.

For most staging environments with test users and dummy data, this isn't an issue. When troubleshooting a production environment, however, you should take measures like invalidating any sessions used and avoid visiting Confluence pages or Jira issues containing personal or sensitive information etc. 

A SAML troubleshooting tip to avoid exposing your password, or having to create a temporary user, is to log into the IDP before running the test. That way, the IDP sees the user is already logged in and doesn't require password entry.

Finally, a HAR file is just a JSON file. You can manually inspect, remove, or replace information in the file, such as passwords, provided it stays syntactically valid.  

Firefox

First, go to the Firefox settings page by putting this in your URL: about:preferences#privacy
On the Privacy page, press Clear Data and select both "Cookies and Site Data" and "Cached Web Content and press Clear and Clear Now.

Next, press F12 or right-click within the page and select Inspect from the context menu.

Then select the Network tab: 

Before beginning the test case/reproducer:

  • Click the trash can to clear the existing log. This removes all items that are irrelevant to the test.

  • Ensure Persist logs have been checked. If not, the event log is automatically cleared between requests, including redirects. 

Finally, run through the actions required to reproduce the issue. When done, right-click any event in the list and select Save as HAR file:

 

Chrome

Press F12 (or CTRL-SHIFT-I), or right-click within the page and select Inspect from the context menu. Then select the Network tab:

Before beginning the test case/reproducer:

  • Click the Clear button to remove any existing items from the log. This removes all items that are irrelevant to the test.

  • Ensure the Preserve log has been checked. If not, the event log is automatically cleared between requests, including redirects. 

Finally, run through the actions required to reproduce the issue. When done, right-click any event in the list and select "Save all as HAR with content":