This only works if you have the correct permissions - for admins only basically.
Let's begin with the permissions.
cp gradle.properties.example ~/.gradle/gradle.properties
Edit that file and set your sonatypeUsername and sonatypePassword`. You also need to set the values for your keys. Here's how to list/create them. 1.
gpg --list-keys
gpg --gen-key
Set the signing.KeyId, signing.password, and the signing.secretKeyRingFile.
The signing.KeyId is the 'pub' one. It's the part of your list of keys that looks something like this: 2048R/5D64A177. So in this scenario it would be 5D64A177. 1 2
The signing.password is the password you used when generating this key. It could be blank if you didn't use a password.
The signing.secretKeyRingFile is the path to the secring.gpg.
Now, upload that key to the keyserver.
gpg --keyserver hkp://pool.sks-keyservers.net --send-keys 5D64A177
Now, you can finally upload! Ah, Java!
./gradlew uploadArchives
Login to Sonatype.
Go to staging repositories page.
Click 'Close' with the archive selected.
Wait a few minutes, and refresh the staging repositories page.
Check the box for the SendGrid repo again and this time click 'Release'.
You're all done.