I recently discovered a great blog post from Craig Bloodworth (@craigbloodworth) in regards to modifying the logo for the login screen and the portal without leveraging the tabadmin command line utility (‘tabadmin customize logo <Filename>’) which presents a problem where the background colours differ in two locations which results in the logo being displayed differently depending on login screen or portal view.
However, in his post Craig has provided a workaround to this issue by modifying the html files with a caveat that this is an unsupported and should be performed at your own risk, even though the steps are simple it is probably an idea to perform a backup before modifying the files.
1. Copy the image file for the login page logo to ‘C:\ProgramData\Tableau\Tableau Server\data\tabsvc\wgserver\images\custom\’.
2. Browse to ‘C:\Program Files\Tableau\Tableau Server\x.x\vizportalclient\public\en\’
3. Edit the file ‘signInLogo.html’ and replace the content with the below specifying the path to your image file in ‘[Your Logo filename]’:
<div tb-width=”signInLogo.width” tb-height=”signInLogo.height” title=”{{ signInLogo.title }}” class=”tb-login-logo”><img src=”/images/custom/[Your Logo filename]” style=”margin-left:-40px;”/></div>
4. Save the file and restart Tableau Server (‘tabadmin restart’) or alternatively terminate the ‘vizportal.exe’ process (‘taskkill -f -im vizportal.exe’) and wait for the process to restart (the quick way!).
As Tableau Server uses a local browser cache you will need to clear you current browsers cache or view in incognito mode to confirm your changes. One issue I did experience was the alignment of my logo which I had to adjust firstly by inspecting the element and modifying the value ‘margin-left -40px;‘ and then saving the change to the file above once this was aligned on the login page.
Finally, when you perform an upgrade to Tableau Server the above configuration will be overwritten so you will need to apply the above steps following each upgrade so probably a good idea to version control your files!
Again, a great article by Craig and provides a workaround to the limitation of the tabadmin command line utility for customising a logo and removes the need to use a .PNG file with transparency.
Deans Blog 