Add support for golang templating in list sub-command

This commit adds support for templating on 'list' sub-command output. It's helping on automation and will allow more custom filtering in output. It's using the https://github.com/intel/tfortools/ project Signed-off-by: Obed N Munoz <[email protected]>
govm-project · Mar 29, 2019 · 1166148 · 1166148
1 parent eacb444
commit 1166148
Show file tree

Hide file tree

Showing 4 changed files with 53 additions and 27 deletions.
diff --git a/README.md b/README.md
@@ -106,17 +106,29 @@ list
 ----
 Lists all virtual machines that were created with the ``govm`` tool. It also shows the VNC access url and name.
 
-| Flag              | Description                       | Required |
-|-------------------|-----------------------------------|----------|
-| --all             | Show VMs from all namespaces      | No       |
-| --namespace value | Show VMs from the given namespace | No       |
+| Flag                     | Description                                    | Required |
+|--------------------------|------------------------------------------------|----------|
+| --all                    | Show VMs from all namespaces                   | No       |
+| --namespace value        | Show VMs from the given namespace              | No       |
+| --format value, -f value | String containing the template code to execute | No       |
 
-*Output example:*
+*Output example*
 ```
-ID          IP           VNC_URL                 NAME
-bd0088a3eb  172.17.0.2   http://localhost:40669  clear-test
-db3ea1be1d  172.17.0.3   http://localhost:35957  cirros-test
-f8a4cd7e93  172.17.0.4   http://localhost:42161  test-30310
+# govm list
+ID         Name                   Namespace IP
+b9b5d3a288 test-14731             onmunoz   172.17.0.6
+4d6731b571 test-29652             onmunoz   172.17.0.5
+ef004385d4 test-20024             onmunoz   172.17.0.4
+5e5f42047b happy-poitras          onmunoz   172.17.0.3
+e90608db45 wonderful-varahamihira onmunoz   172.17.0.2
+```
+
+*Filtered output*
+```
+# govm list -f '{{select (filterRegexp . "Name" "test-*") "IP"}}'
+172.17.0.6
+172.17.0.5
+172.17.0.4
 ```
 
 compose

diff --git a/engines/docker/engine.go b/engines/docker/engine.go
@@ -250,7 +250,6 @@ func (e Engine) setVNC(vncID string, port string) error {
 		_, err := e.docker.Create(containerConfig, hostConfig,
 			&network.NetworkingConfig{}, VNCServerContainerName)
 		if err != nil {
-			fmt.Println(err)
 			return err
 		}
 	}

diff --git a/go.mod b/go.mod
@@ -1,16 +1,18 @@
 module github.com/govm-project/govm
 
 require (
-	github.com/codegangsta/cli v1.20.0
+	github.com/Microsoft/go-winio v0.4.12 // indirect
 	github.com/docker/distribution v2.6.2+incompatible // indirect
 	github.com/docker/docker v1.13.1
 	github.com/docker/go-connections v0.4.0 // indirect
 	github.com/docker/go-units v0.3.3 // indirect
 	github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b
 	github.com/google/go-cmp v0.2.0
-	github.com/moby/moby v1.13.1
+	github.com/intel/tfortools v0.2.0
+	github.com/kr/pretty v0.1.0 // indirect
 	github.com/pkg/errors v0.8.0 // indirect
 	github.com/sirupsen/logrus v1.1.0
+	github.com/stevvooe/resumable v0.0.0-20180830230917-22b14a53ba50 // indirect
 	golang.org/x/crypto v0.0.0-20181001203147-e3636079e1a4
 	golang.org/x/net v0.0.0-20181003013248-f5e5bdd77824
 	golang.org/x/sys v0.0.0-20181003145944-af653ce8b74f

diff --git a/pkg/cli/list.go b/pkg/cli/list.go
@@ -3,11 +3,10 @@ package cli
 import (
 	"fmt"
 	"os"
-	"text/tabwriter"
 
 	"github.com/govm-project/govm/engines/docker"
 
-	log "github.com/sirupsen/logrus"
+	"github.com/intel/tfortools"
 	cli "gopkg.in/urfave/cli.v2"
 )
 
@@ -21,31 +20,45 @@ var listCommand = cli.Command{
 			Aliases: []string{"a"},
 			Usage:   "list VMs from all namespaces",
 		},
+		&cli.StringFlag{
+			Name:    "format",
+			Aliases: []string{"f"},
+			Usage:   "string containing the template code to execute",
+		},
 	},
 	Action: func(c *cli.Context) error {
 
 		engine := docker.Engine{}
 		engine.Init()
 
-		instances, err := engine.List(c.String("namespace"), c.Bool("all"))
+		result, err := engine.List(c.String("namespace"), c.Bool("all"))
 		if err != nil {
 			return err
 		}
 
-		w := tabwriter.NewWriter(os.Stdout, 0, 0, 2, ' ', 0)
-		fmt.Fprintln(w, "ID\tName\tNamespace\tIP\tVNC")
-		for _, instance := range instances {
-			fmt.Fprintf(w, "%s\t%s\t%s\t%s\t%s\n",
-				instance.ID,
-				instance.Name,
-				instance.Namespace,
-				instance.NetOpts.IP,
-				fmt.Sprintf("http://localhost:%v", instance.VNCPort),
-			)
+		// Required due a limitation on intel/tfortools for embedded structures
+		// https://github.com/intel/tfortools/issues/18
+		type outInstance struct {
+			ID        string
+			Name      string
+			Namespace string
+			IP        string
+		}
+
+		instances := []outInstance{}
+		for _, elem := range result {
+			instances = append(instances, outInstance{elem.ID, elem.Name, elem.Namespace, elem.NetOpts.IP})
 		}
-		err = w.Flush()
+
+		format := c.String("format")
+		if format == "" {
+			format = `{{table .}}`
+		}
+
+		err = tfortools.OutputToTemplate(os.Stdout, "format", format, instances, nil)
 		if err != nil {
-			log.Fatal(err)
+			fmt.Fprintln(os.Stderr, tfortools.GenerateUsageDecorated("format", instances, nil))
+			return fmt.Errorf("Unable to execute template : %v", err)
 		}
 
 		return nil