Split config database setup by platform

Add basic database setup for AWS, GCP although these are not yet used
by the setup code but will be useful later.

Currently each is gated by `mobyplatform` but this can be removed once we
construct Moby per platform, and once these are containerised so they
are not run from `openrc`.

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

alpine/packages/mobyconfig/usr/bin/mobyconfig

@@ -2,35 +2,10 @@
 
 if [ $# -ne 2 ]
 then
-  printf "usage: $0 [get|exists|path|dir|find] key\n"
+  printf "usage: $0 [get|set|wait|exists|path|dir|find] key\n"
   exit 0
 fi
 
-if [ $1 == "set" ]
-then
-  printf "Configuration is immutable\n" 1>&2
-  exit 1
-fi
-
-if [ ! -d /Database ]
-then
-  mkdir -p /Database
-  case "$(mobyplatform)" in
-    windows)
-      mkdir -p /tmp/db
-      /sbin/9pmount-vsock listen db /tmp/db
-      [ $? -ne 0 ] && rm -rf /Database && printf "Could not mount configuration database\n" 1>&2 && exit 1
-      mount --bind /tmp/db/branch/master/ro/com.docker.driver.amd64-linux /Database
-    ;;
-    mac)
-      mkdir -p /tmp/db
-      mount -t 9p -o trans=virtio,dfltuid=1001,dfltgid=50,version=9p2000 db /tmp/db
-      [ $? -ne 0 ] && rm -rf /Database && printf "Could not mount configuration database\n" 1>&2 && exit 1
-      mount --bind /tmp/db/branch/master/ro/com.docker.driver.amd64-linux /Database
-    ;;
-  esac
-fi
-
 BASE=/Database
 
 KEY=$(echo $2 | sed 's@^/@@')
@@ -61,6 +36,22 @@ then
   fi
 fi
 
+if [ $1 == "set" ]
+then
+  mkdir -p $(dirname "${BASE}/${KEY}")
+  cat - > ${BASE}/${KEY}
+  exit 0
+fi
+
+if [ $1 == "wait" ]
+then
+  while [ ! -s ${BASE}/${KEY} ]
+  do
+    sleep 1
+  done
+  exit 0
+fi
+
 if [ $1 == "path" ]
 then
   if [ -e ${BASE}/${KEY} ]
@@ -85,5 +76,5 @@ then
   fi
 fi
 
-printf "usage: $0 [get|exists|path|dir|find] key\n"
+printf "usage: $0 [get|set|wait|exists|path|dir|find] key\n"
 exit 1