Add proof of concept server ls comand

Reviewed-on: coop-cloud/go-abra#1

.drone.yml

@@ -0,0 +1,8 @@
+---
+kind: pipeline
+name: coopcloud.tech/abra
+steps:
+  - name: make build
+    image: golang:1.16
+    commands:
+      - make build

.gitignore

@@ -0,0 +1 @@
+abra

Makefile

@@ -1,14 +1,18 @@
 COMMIT  := $(shell git rev-list -1 HEAD)
 VERSION := $(shell cat ./version)
 GOPATH  := $(shell go env GOPATH)
+LDFLAGS := "-X 'main.Commit=$(COMMIT)' -X 'main.Version=$(VERSION)'"
 
-all: run
+all: run install build clean
 
 run:
-	go run -ldflags="-X 'main.Commit=$(COMMIT)' -X 'main.Version=$(VERSION)'" ./cmd/abra
+	go run -ldflags=$(LDFLAGS) ./cmd/abra
 
 install:
-	go install -ldflags="-X 'main.Commit=$(COMMIT)' -X 'main.Version=$(VERSION)'" ./cmd/abra
+	go install -ldflags=$(LDFLAGS) ./cmd/abra
+
+build:
+	go build -ldflags=$(LDFLAGS) ./cmd/abra
 
 clean:
 	rm '$(GOPATH)/bin/abra'

README.md

@@ -1,3 +1,5 @@
 # go-abra
 
-WIP port of abra to Golang.
+[![Build Status](https://drone.autonomic.zone/api/badges/coop-cloud/go-abra/status.svg?ref=refs/heads/main)](https://drone.autonomic.zone/coop-cloud/go-abra)
+
+WIP port of [abra](https://git.autonomic.zone/coop-cloud/abra) to Golang.

cli/server.go

@@ -2,6 +2,10 @@ package cli
 
 import (
 	"fmt"
+    "io/ioutil"
+    "os"
+    "os/exec"
+    "log"
 
 	"github.com/urfave/cli/v2"
 )
@@ -12,6 +16,27 @@ var serverListCommand = &cli.Command{
 	Usage:     "List locally-defined servers.",
 	ArgsUsage: emptyArgsUsage,
 	HideHelp:  true,
+    Action: func(c *cli.Context) error {
+        abradir := os.Getenv("HOME") + "/.abra"
+
+        servers, err := ioutil.ReadDir(abradir + "/servers")
+        if err != nil {
+            log.Fatal(err)
+        }
+        fmt.Println("\033[33mLoading status from", len(servers), "server(s), patience advised...\033[0m")
+        fmt.Println(len(servers), "servers:\n")
+        fmt.Println("  NAME\tCONNECTION")
+        fmt.Println("  --\t--")
+        for _, s := range servers {
+            conn, err := exec.Command("docker", "context", "inspect", s.Name(), "-f", "{{.Endpoints.docker.Host}}").Output()
+            if err != nil {
+                log.Fatal(err)
+            }
+            fmt.Printf("  %s\t%s\n", s.Name(), string(conn))
+        }
+
+        return nil
+    },
 }
 
 var serverAddCommand = &cli.Command{