Allow enabling gitlab-shell "discover"-feature

This adds the possibility to enable features for GitLab shell.

The first feature being recognized is "Discover": It's the command
that is executed when running `ssh git@gitlab.example.com` and is
called without a command.

The gitlab key id or username is already parsed from the command line
arguments.

Currently we only support communicating with GitLab-rails using unix
sockets. So features will not be enabled if the GitLab-url is using a
different protocol. The url for this read from the config yaml.

Pending ruby-specs have been added for the gitlab-shell command.

Refactor to have separate command packages

1 files changed, 19 insertions, 0 deletions

diff --git a/go/internal/command/fallback/fallback.go b/go/internal/command/fallback/fallback.go
new file mode 100644
index 0000000..a136657
--- /dev/null
+++ b/go/internal/command/fallback/fallback.go
@@ -0,0 +1,19 @@
+package fallback
+
+import (
+	"os"
+	"path/filepath"
+	"syscall"
+)
+
+type Command struct{}
+
+var (
+	binDir = filepath.Dir(os.Args[0])
+)
+
+func (c *Command) Execute() error {
+	rubyCmd := filepath.Join(binDir, "gitlab-shell-ruby")
+	execErr := syscall.Exec(rubyCmd, os.Args, os.Environ())
+	return execErr
+}