Create a folder named "tomcat6-myapp" in /usr/share.
Create a folder "myapp" under /usr/share/tomcat6-myapp.
Copy the HTML file (that I need to deploy) to /usr/share/tomcat6-myapp/myapp. It must be named index.html.
Go to /etc/tomcat6/Catalina/localhost.
Create an xml file "myapp.xml" (i guess it must have the same name as the name of the folder in step 2) inside /etc/tomcat6/Catalina/localhost with the following contents.
If you using chrome web browser and did wrong folder before, then clean web browser's cache(or change another name) otherwise (sometimes) it always 404.
If you want to create a .war file you can deploy to a Tomcat instance using the Manager app, create a folder, put all your files in that folder (including an index.html file) move your terminal window into that folder, and execute the following command:
zip -r <AppName>.war *
I've tested it with Tomcat 8 on the Mac, but it should work anywhere
I struggled a bit with older version of Apache Tomcat (7.0.68) running on Windows Server 2012, but this worked for me after a little bit of experimenting:
Create app folder with your static files (HTML, JS, CSS, assets, etc.).
Inside the folder create META-INF folder and add empty MANIFEST.MF.
Optionally zip the app folder and change the extension to .war.
Upload your app to Tomcat's webapps folder, either as a .war or just folder with your files.
Turned out, that META-INF with empty MANIFEST.MF file is enough for Tomcat to serve the app. No need to add WEB-INF or anything else (at least for my version of Tomcat).