Use the user's ssh key automatically in ssh examples

This requires moby tool update to support `~` in paths, but
makes everything much nicer.

Signed-off-by: Justin Cormack <justin.cormack@docker.com>

examples/azure.yml

@@ -18,7 +18,9 @@ services:
     image: "linuxkit/sshd:abc1f5e096982ebc3fb61c506aed3ac9c2ae4d55"
 files:
   - path: root/.ssh/authorized_keys
-    contents: '#public ssh key here'
+    source: ~/.ssh/id_rsa.pub
+    mode: "0600"
+    optional: true
 trust:
   org:
     - linuxkit

examples/packet.yml

@@ -18,7 +18,9 @@ services:
     image: "linuxkit/sshd:abc1f5e096982ebc3fb61c506aed3ac9c2ae4d55"
 files:
   - path: root/.ssh/authorized_keys
-    contents: '#your ssh key here'
+    source: ~/.ssh/id_rsa.pub
+    mode: "0600"
+    optional: true
 trust:
   org:
     - linuxkit

examples/sshd.yml

@@ -22,7 +22,9 @@ services:
     image: "linuxkit/sshd:abc1f5e096982ebc3fb61c506aed3ac9c2ae4d55"
 files:
   - path: root/.ssh/authorized_keys
-    contents: '#your ssh key here'
+    source: ~/.ssh/id_rsa.pub
+    mode: "0600"
+    optional: true
 trust:
   org:
     - linuxkit

examples/vpnkit-forwarder.yml

@@ -37,7 +37,9 @@ services:
 
 files:
   - path: root/.ssh/authorized_keys
-    contents: '#your ssh key here'
+    source: ~/.ssh/id_rsa.pub
+    mode: "0600"
+    optional: true
 
 trust:
   org: