fix: better borked ssh config message

See coop-cloud/organising#243.

cli/app/list.go

@@ -6,6 +6,7 @@ import (
 	"strings"
 
 	abraFormatter "coopcloud.tech/abra/cli/formatter"
+	"coopcloud.tech/abra/cli/internal"
 	"coopcloud.tech/abra/pkg/catalogue"
 	"coopcloud.tech/abra/pkg/config"
 	"coopcloud.tech/abra/pkg/ssh"
@@ -72,7 +73,7 @@ can take some time.
 
 		for _, app := range apps {
 			if err := ssh.EnsureHostKey(app.Server); err != nil {
-				logrus.Fatal(err)
+				logrus.Fatal(fmt.Sprintf(internal.SSHFailMsg, app.Server))
 			}
 		}
 

cli/internal/common.go

@@ -271,3 +271,42 @@ var DebugFlag = &cli.BoolFlag{
 	Destination: &Debug,
 	Usage:       "Show DEBUG messages",
 }
+
+// SSHFailMsg is a hopefully helpful SSH failure message
+var SSHFailMsg = `
+Woops, Abra is unable to connect to connect to %s.
+
+Here are a few tips for debugging your local SSH config. Abra uses plain 'ol
+SSH to make connections to servers, so if your SSH config is working, Abra is
+working.
+
+Is your ssh-agent running? You can start it by running the following command:
+
+    eval "$(ssh-agent)"
+
+If your SSH private key loaded? You can check by running the following command:
+
+    ssh-add -L
+
+If you are using a non-default public/private key, you can configure this in
+your ~/.ssh/config file which Abra will read in order to figure out connection
+details:
+
+Host foo.coopcloud.tech
+  Hostname foo.coopcloud.tech
+  User bar
+  Port 12345
+  IdentityFile ~/.ssh/bar@foo.coopcloud.tech
+
+If you're only using password authentication, you can use the following config:
+
+Host foo.coopcloud.tech
+  Hostname foo.coopcloud.tech
+  User bar
+  Port 12345
+  PreferredAuthentications=password
+  PubkeyAuthentication=no
+
+Good luck!
+
+`