component/dis: Check if instance alive

internal/component/dis/info.go

@@ -1,26 +1,70 @@
 package dis
 
 import (
+	"encoding/json"
 	"net/http"
 
+	"github.com/FAU-CDI/wisski-distillery/internal/component/instances"
 	"github.com/tkw1536/goprogram/stream"
+	"golang.org/x/sync/errgroup"
 )
 
-func (dis Dis) info(io stream.IOStream) (http.Handler, error) {
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		all, err := dis.Instances.All()
-		if err != nil {
-			w.WriteHeader(http.StatusInternalServerError)
-			w.Write([]byte("internal server error"))
-			io.EPrintln(err)
-			return
-		}
-
-		for _, wk := range all {
-			w.WriteHeader(http.StatusOK)
-			w.Write([]byte(wk.Slug))
-			w.Write([]byte("\n"))
-		}
-
-	}), nil
+func (dis *Dis) info(io stream.IOStream) (http.Handler, error) {
+	return http.HandlerFunc(dis.handleDis), nil
+}
+
+const disLimit = 2
+
+func (dis *Dis) handleDis(w http.ResponseWriter, r *http.Request) {
+	// make sure the user is authorized
+	if !dis.authDis(r) {
+		w.Header().Add("WWW-Authenticate", `Basic realm="WissKI Distillery Admin"`)
+		w.WriteHeader(http.StatusUnauthorized)
+		w.Write([]byte("Unauthorized"))
+		return
+	}
+
+	// create a new error group
+	var errgroup errgroup.Group
+	errgroup.SetLimit(disLimit)
+
+	// list all the instances
+	all, err := dis.Instances.All()
+	if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		w.Write([]byte("internal server error"))
+		return
+	}
+
+	// get all of their info!
+	infos := make([]instances.Info, len(all))
+	for i, instance := range all {
+		{
+			i := i
+			instance := instance
+
+			errgroup.Go(func() (err error) {
+				infos[i], err = instance.Info()
+				return err
+			})
+		}
+	}
+
+	// if some info call failed
+	if err := errgroup.Wait(); err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		w.Write([]byte("internal server error"))
+		w.Write([]byte("\n"))
+		return
+	}
+
+	// and return the json
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(http.StatusOK)
+	json.NewEncoder(w).Encode(infos)
+}
+
+func (dis *Dis) authDis(r *http.Request) bool {
+	user, pass, ok := r.BasicAuth()
+	return ok && user == dis.Config.DisAdminUser && pass == dis.Config.DisAdminPassword
 }

internal/component/dis/stack/Dockerfile

@@ -1,4 +1,4 @@
-FROM docker.io/library/alpine
+FROM docker.io/library/docker:20.10-cli
 
 COPY wdcli /wdcli
 EXPOSE 8888

internal/component/dis/stack/docker-compose.yml

@@ -1,7 +1,7 @@
 version: "3.7"
 
 services:
-  wdresolve:
+  dis:
     build: .
     restart: always
     environment:
@@ -16,6 +16,8 @@ services:
       LETSENCRYPT_EMAIL: ${LETSENCRYPT_EMAIL}
 
     volumes:
+      # TODO: Mount docker socket properly!
+      - "/var/run/docker.sock:/var/run/docker.sock"
       - "${CONFIG_PATH}:${CONFIG_PATH}:ro"
       - "${DEPLOY_ROOT}:${DEPLOY_ROOT}:ro"
       - "${GLOBAL_AUTHORIZED_KEYS_FILE}:${GLOBAL_AUTHORIZED_KEYS_FILE}:ro"

internal/component/instances/wisski_status.go

@@ -0,0 +1,22 @@
+package instances
+
+import "github.com/tkw1536/goprogram/stream"
+
+// Info represents some info about this WissKI
+type Info struct {
+	Slug string // The slug of the instance
+
+	Running bool // is the instance running?
+}
+
+// Info returns info about this instance
+func (wisski *WissKI) Info() (info Info, err error) {
+	info.Slug = wisski.Slug
+
+	ps, err := wisski.Barrel().Ps(stream.FromNil())
+	if err != nil {
+		return
+	}
+	info.Running = len(ps) > 0
+	return
+}

internal/component/stack.go

@@ -2,6 +2,8 @@
 package component
 
 import (
+	"bufio"
+	"bytes"
 	"errors"
 
 	"github.com/FAU-CDI/wisski-distillery/pkg/execx"
@@ -119,6 +121,38 @@ func (ds Stack) Restart(io stream.IOStream) error {
 	return nil
 }
 
+var errStackPs = errors.New("Stack.Ps: Down returned non-zero exit code")
+
+// Ps returns the ids of the containers currently running
+func (ds Stack) Ps(io stream.IOStream) ([]string, error) {
+	// create a buffer
+	var buffer bytes.Buffer
+
+	// read the ids from the command!
+	code, err := ds.compose(io.Streams(&buffer, nil, nil, 0), "ps", "-q")
+	if err != nil {
+		return nil, err
+	}
+	if code != 0 {
+		return nil, errStackPs
+	}
+
+	// scan each of the lines
+	var results []string
+	scanner := bufio.NewScanner(&buffer)
+	for scanner.Scan() {
+		if text := scanner.Text(); text != "" {
+			results = append(results, text)
+		}
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	// return them!
+	return results, nil
+}
+
 var errStackDown = errors.New("Stack.Down: Down returned non-zero exit code")
 
 // Down stops and removes all containers in this Stack.