refactor: more seamless SSH connections

cli/server/add.go

@@ -316,14 +316,10 @@ to start running Abra commands against it.
 
 This command can also provision your server ("--provision/-p") so that it is
 capable of hosting Co-op Cloud apps. Abra will default to expecting that you
-have a working SSH config for the host in your ~/.ssh/config file. E.g. for
-"example.com", you'll want to have something like:
-
-Host example.com
-  Hostname 192.168.178.31  # domain name also works
-  User myuserontheserver
-  Port 12345
-  IdentityFile ~/.ssh/mysecretkey.local
+have a running ssh-agent and are using SSH keys to connect to your new server.
+Abra will also read your SSH config (matching "Host" as <domain>). SSH
+connection details precedence follows as such: command-line > SSH config >
+guessed defaults.
 
 If you have no SSH key configured for this host and are instead using password
 authentication, you may pass "--ssh-auth password" to have Abra ask you for the
@@ -345,7 +341,7 @@ Example:
 
     abra server add --provision --traefik varia.zone glodemodem 12345
 
-Abra will construct the following SSH connection string then:
+Abra will construct the following SSH connection and Docker context:
 
     ssh://globemodem@varia.zone:12345
 

cli/server/new.go

@@ -84,20 +84,7 @@ Your new Hetzner Cloud VPS has successfully been created! Here are the details:
     VPS IP address: %s
     VPS Root Password: %s
 
-Here is what your SSH configuration (~/.ssh/config) might look like:
-
-    Host %s.example.com
-      Hostname %s
-      User root
-      Port 22
-      IdentityFile ~/.ssh/<your-ssh-private-key>
-
-Remember, your "Host" value must be a valid publicly accessible domain name as
-Abra uses this domain to identity servers. If you specified "--ssh-auth
-password" then you may skip the IdentityFile stanza.
-
-Once your SSH client is configured, you can access this new VPS via SSH using
-the following command:
+You can access this new VPS via SSH using the following command:
 
     ssh root@%s
 
@@ -107,7 +94,6 @@ record new") and add the server to your Abra configuration ("abra server add")
 to have a working server that you can deploy Co-op Cloud apps to.
 	`,
 		internal.HetznerCloudName, ip, rootPassword,
-		internal.HetznerCloudName, ip,
 		ip,
 	))
 

pkg/ssh/ssh.go

@@ -1,7 +1,6 @@
 package ssh
 
 import (
-	"fmt"
 	"os/user"
 
 	"github.com/AlecAivazis/survey/v2"
@@ -19,7 +18,7 @@ type HostConfig struct {
 }
 
 // GetHostConfig retrieves a ~/.ssh/config config for a host.
-func GetHostConfig(hostname, username, port string, hasIdentityFile bool) (HostConfig, error) {
+func GetHostConfig(hostname, username, port string) (HostConfig, error) {
 	var hostConfig HostConfig
 
 	var host, idf string
@@ -47,13 +46,12 @@ func GetHostConfig(hostname, username, port string, hasIdentityFile bool) (HostC
 		}
 	}
 
-	dummyVal := "~/.ssh/identity"
-	if idf = ssh_config.Get(hostname, "IdentityFile"); (idf == dummyVal || idf == "") && hasIdentityFile {
-		return hostConfig, fmt.Errorf("SSH identity file missing for %s from SSH config", hostname)
-	}
+	idf = ssh_config.Get(hostname, "IdentityFile")
 
 	hostConfig.Host = host
-	hostConfig.IdentityFile = idf
+	if idf != "" {
+		hostConfig.IdentityFile = idf
+	}
 	hostConfig.Port = port
 	hostConfig.User = username
 
@@ -66,12 +64,7 @@ func GetHostConfig(hostname, username, port string, hasIdentityFile bool) (HostC
 func New(domainName, sshAuth, username, port string) (*simplessh.Client, error) {
 	var client *simplessh.Client
 
-	hasIdentityFile := true
-	if sshAuth == "password" {
-		hasIdentityFile = false
-	}
-
-	hostConfig, err := GetHostConfig(domainName, username, port, hasIdentityFile)
+	hostConfig, err := GetHostConfig(domainName, username, port)
 	if err != nil {
 		return client, err
 	}