Update install for buster

Add the correct libre2 package name for Debian buster, and also
update the quickstart playbook and documentation to deal with
the change in default rsa key encoding format from newer
versions of ssh-keygen.

Change-Id: I6ada88cd896d844c1171f7bcaf4691dea023d51f

bindep.txt

@@ -34,6 +34,7 @@ python3.7 [test platform:ubuntu-bionic]
 python3.7-dev [test platform:ubuntu-bionic]
 bubblewrap [!platform:ubuntu-xenial]
 libre2-dev [compile test platform:dpkg]
+libre2-5 [platform:debian-buster]
 libre2-4 [platform:ubuntu-bionic]
 libre2-3 [platform:debian-stretch]
 libre2-1v5 [platform:ubuntu-xenial]

doc/source/admin/components.rst

@@ -580,6 +580,10 @@ The following sections of ``zuul.conf`` are used by the executor:
 
       SSH private key file to be used when logging into worker nodes.
 
+      .. note:: If you use an RSA key, ensure it is encoded in the PEM
+                format (use the ``-t rsa -m PEM`` arguments to
+                `ssh-keygen`).
+
    .. attr:: default_username
       :default: zuul
 

doc/source/admin/drivers/gerrit.rst

@@ -15,6 +15,10 @@ create a Gerrit user with that key::
 
   cat ~/id_rsa.pub | ssh -p29418 review.example.com gerrit create-account --ssh-key - --full-name Zuul zuul
 
+.. note:: If you use an RSA key, ensure it is encoded in the PEM
+          format (use the ``-t rsa -m PEM`` arguments to
+          `ssh-keygen`).
+
 Give that user whatever permissions will be needed on the projects you
 want Zuul to report on.  For instance, you may want to grant
 ``Verified +/-1`` and ``Submit`` to the user.  Additional categories

doc/source/admin/examples/playbooks/setup.yaml

@@ -10,11 +10,11 @@
       args:
         creates: /var/ssh/admin.pub
     - name: Generate Zuul SSH key for Gerrit
-      command: ssh-keygen -f /var/ssh/zuul -N ''
+      command: ssh-keygen -f /var/ssh/zuul -N '' -t rsa -m PEM
       args:
         creates: /var/ssh/zuul.pub
     - name: Generate Zuul SSH key for Nodepool
-      command: ssh-keygen -f /var/ssh/nodepool -N ''
+      command: ssh-keygen -f /var/ssh/nodepool -N '' -t rsa -m PEM
       args:
         creates: /var/ssh/nodepool.pub
     - name: Add Nodepool key to node authorized_keys file

doc/source/admin/nodepool_install.rst

@@ -14,7 +14,7 @@ into the nodes that Nodepool provides.
 
    sudo groupadd --system nodepool
    sudo useradd --system nodepool --home-dir /var/lib/nodepool --create-home -g nodepool
-   ssh-keygen -t rsa -b 2048 -f nodepool_rsa  # don't enter a passphrase
+   ssh-keygen -t rsa -m PEM -b 2048 -f nodepool_rsa  # don't enter a passphrase
    sudo mkdir /etc/nodepool/
    sudo mkdir /var/log/nodepool
    sudo chgrp -R nodepool /var/log/nodepool/