The first time Jenkins starts up, a security token is generated and printed in the console log. Usernameadmin
The icon should look something like this:
*************************************************************
Jenkins initial setup is required. A security token is required to proceed.
Please use the following security token to proceed to installation:
41d2b60b0e4cb5bf2025d33b21cb
*************************************************************
For me, the initial administrator password was in the log in ~/.jenkins/secrets/initialAdminPassword
after installation using homegrown.
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