diff --git a/README.md b/README.md index 19d335b..e277852 100644 --- a/README.md +++ b/README.md @@ -55,7 +55,7 @@ backup: # ... environment: # ... - + # when to run backups # default: "36 03 * * *" <=> daily at 03:36 am SCHEDULE_BACKUP: "36 03 * * *" @@ -118,7 +118,95 @@ backup: ## Encryption -For effective use of GnuPG encryption, you will need a custom `Dockerfile`. +For effective use of GnuPG encryption, you will need a GnuPG key and a custom `Dockerfile`. + +### Creating a GnuPG key + +If you already have one key you want to use for this instance, skip this section. + +#### Preparation + +First, change to a safe directory, e.g. a new dir inside your home directory: `mkdir ~/kiwi-backup && cd ~/kiwi-backup` + +#### Generation + +Run key generation wizard using the following command and follow its directions: + +```sh +docker run --rm -it -v "$(pwd)/gnupg:/root/.gnupg" ldericher/kiwi-backup gpg --full-generate-key +``` + +Good default choices for backup purposes are: + +* Kind of key: `1` (RSA/RSA) +* Keysize `4096` +* Validity `0` (doesn't expire), confirm with `y` +* Real name `Administrator` +* Email address `root@` +* Comment (empty) +* Confirm with `O` +* Input a passphrase (choose a secure password, it will be saved with your `kiwi-scp` instance!) + +#### Key-ID + +There's an output line `gpg: key 38CD19177F84710B marked as ultimately trusted` where `38CD19177F84710B` will be your Key-ID. If you lost it, you can list the keys using `gpg -k`: + +```sh +docker run --rm -it -v "$(pwd)/gnupg:/root/.gnupg" ldericher/kiwi-backup gpg -k | grep -A1 '^pub' +``` + +Output: + +``` +pub rsa4096 2020-08-27 [SC] + 82BA35B0871675F78165618238CD19177F84710B +``` + +You can use the full fingerprint `82BA35B0871675F78165618238CD19177F84710B` or abbreviate to the last 16 digits `38CD19177F84710B`. Checking your Key-ID should succeed: + +```sh +docker run --rm -it -v "$(pwd)/gnupg:/root/.gnupg" ldericher/kiwi-backup gpg --fingerprint 38CD19177F84710B +``` + +For more possibilities of what counts as a Key-ID, refer to [the relevant GnuPG manual section](https://www.gnupg.org/documentation/manuals/gnupg/Specify-a-User-ID.html) + +#### Export the key + +First, export the secret key. + +```sh +docker run --rm -it -v "$(pwd)/gnupg:/root/.gnupg" -v "$(pwd)/gpg-export:/root/gpg-export" ldericher/kiwi-backup sh -c 'gpg --export-secret-keys --armor > /root/gpg-export/secret.asc' +``` + +Then, export the trust value. + +```sh +docker run --rm -it -v "$(pwd)/gnupg:/root/.gnupg" -v "$(pwd)/gpg-export:/root/gpg-export" ldericher/kiwi-backup sh -c 'gpg --export-ownertrust > /root/gpg-export/ownertrust.txt' +``` + +Optionally, spawn a fresh container to check your export: + +```sh +docker run --rm -it -v "$(pwd)/gpg-export:/root/gpg-export:ro" ldericher/kiwi-backup sh +``` + +Inside the container, import the key. It should then appear in the list: + +``` +/ # gpg --import /root/gpg-export/secret.asc +[...] + +/ # gpg --import-ownertrust /root/gpg-export/ownertrust.txt +gpg: inserting ownertrust of 6 + +/ # gpg -k +[...] +pub rsa4096 2020-08-27 [SC] + 82BA35B0871675F78165618238CD19177F84710B +[...] +``` + +#### ## Offsite Backups