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Support multiple namespaces (#15)
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* `-n` switch accepts an optional comma-separated list of namespaces
* Breaking change: Negative RegEx is now handled using `-x`
 
If a list of namespaces is provided for the `-n` option, each command is now run against _each_ namespace for _each_ context

Fix #14

Co-authored-by: Sumit Kumar M <[email protected]>
Co-authored-by: Jonny <[email protected]>
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@sumitkumarm @jonnylangefeld
3 people authored May 28, 2021
1 parent 63fff2b commit d164eaf
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Showing 3 changed files with 53 additions and 31 deletions.
65 changes: 43 additions & 22 deletions pkg/mc/mc.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,17 +36,18 @@ var (

// MC contains the options of the command
type MC struct {
Cmd *cobra.Command
Regex string
NegRegex string
ListOnly bool
MaxProc int
Debug bool
Output string
Cmd *cobra.Command
Regex string
NegRegex string
Namespaces string
ListOnly bool
MaxProc int
Debug bool
Output string

// to allow dependency injection
getListContextsCmd func() Cmd
getKubectlCmd func(args []string, context string) Cmd
getKubectlCmd func(args []string, context string, namespace string) Cmd
}

// Cmd is an interface for exec.Cmd to allow for dependency injection
Expand All @@ -63,8 +64,8 @@ func New(version string) *MC {
mc.getListContextsCmd = func() Cmd {
return exec.Command("kubectl", []string{"config", "get-contexts", "-o", "name"}...)
}
mc.getKubectlCmd = func(args []string, context string) Cmd {
return exec.Command("kubectl", getLocalArgs(args, context)...)
mc.getKubectlCmd = func(args []string, context string, namespace string) Cmd {
return exec.Command("kubectl", getLocalArgs(args, context, namespace)...)
}

cmd := &cobra.Command{
Expand Down Expand Up @@ -112,7 +113,8 @@ mc -r kind -o json -- get pods -n kube-system | jq 'keys[] as $k | "\($k) \(.[$k
}

cmd.Flags().StringVarP(&mc.Regex, "regex", "r", mc.Regex, "a regex to filter the list of context names in kubeconfig. If not given all contexts are used")
cmd.Flags().StringVarP(&mc.NegRegex, "negative-regex", "n", mc.NegRegex, "a regex to exclude matches from the result set. Evaluated succeeding to the including regex filter")
cmd.Flags().StringVarP(&mc.NegRegex, "negative-regex", "x", mc.NegRegex, "a regex to exclude matches from the result set. Evaluated succeeding to the including regex filter")
cmd.Flags().StringVarP(&mc.Namespaces, "namespaces", "n", mc.Namespaces, "comma-separated list of namespaces. Overrides namespace(s) specified in kubectl command. The default is the current namespace of the context")
cmd.Flags().BoolVarP(&mc.ListOnly, "list-only", "l", mc.ListOnly, "just list the contexts matching the regex. Good for testing your regex")
cmd.Flags().IntVarP(&mc.MaxProc, "max-processes", "p", 5, "max amount of parallel kubectl to be executed. Can be used to limit cpu activity")
cmd.Flags().BoolVarP(&mc.Debug, "debug", "d", mc.Debug, "enable debug output")
Expand Down Expand Up @@ -149,9 +151,11 @@ func (mc *MC) run(args []string) error {
wait := make(chan bool)
var mutex = &sync.Mutex{}

namespaces := strings.Split(mc.Namespaces, ",")

logger.Debug("start wait group")
go func() {
for i := 0; i < len(contexts); i++ {
for i := 0; i < len(contexts)*len(namespaces); i++ {
<-done
parallelProc <- true
}
Expand All @@ -161,10 +165,12 @@ func (mc *MC) run(args []string) error {

output := map[string]json.RawMessage{}
for _, c := range contexts {
logger.Debug("waiting for next free spot", zap.String("context", c))
<-parallelProc
logger.Debug("executing", zap.String("context", c))
go do(done, c, output, mc.Output == "", mc.Cmd.OutOrStdout(), mc.getKubectlCmd(args, c), mutex)
for _, ns := range namespaces {
logger.Debug("waiting for next free spot", zap.String("context", c), zap.String("namespace", ns))
<-parallelProc
logger.Debug("executing", zap.String("context", c), zap.String("namespace", ns))
go do(done, c, ns, output, mc.Output == "", mc.Cmd.OutOrStdout(), mc.getKubectlCmd(args, c, ns), mutex)
}
}
<-wait
if mc.Output != "" {
Expand Down Expand Up @@ -221,16 +227,21 @@ func (mc *MC) listContexts(cmd Cmd) (contexts []string, err error) {
}

// do executes a command against kubectl and sends a bool to the done channel when done
func do(done chan bool, context string, output map[string]json.RawMessage, writeToStdout bool, out io.Writer, cmd Cmd, mutex *sync.Mutex) {
func do(done chan bool, context string, namespace string, output map[string]json.RawMessage, writeToStdout bool, out io.Writer, cmd Cmd, mutex *sync.Mutex) {
stdout, err := kubectl(cmd)
if err != nil {
stdout = []byte(err.Error())
}
mutex.Lock()
output[context] = stdout

cns := context
if namespace != "" {
cns += ": " + namespace
}
output[cns] = stdout
mutex.Unlock()
if writeToStdout {
fmt.Fprint(out, formatContext(context, stdout))
fmt.Fprint(out, formatContext(context, namespace, stdout))
}
done <- true
}
Expand All @@ -247,18 +258,25 @@ func kubectl(cmd Cmd) ([]byte, error) {
// getLocalArgs transforms kubectl args slice by injecting the context flag into the right position.
// if the kubectl command contained `--` (for instance for a `kubectl exec` command, we inject the context flag before
// that.
func getLocalArgs(args []string, context string) (localArgs []string) {
func getLocalArgs(args []string, context string, namespace string) (localArgs []string) {

var skipContext bool
for _, arg := range args {
if arg == "--" {
// If this is given, we need to insert the context before this arg
localArgs = append(localArgs, "--context", context)
if len(namespace) > 0 {
localArgs = append(localArgs, "--namespace", namespace)
}
skipContext = true
}
localArgs = append(localArgs, arg)
}
if !skipContext {
localArgs = append(localArgs, "--context", context)
if len(namespace) > 0 {
localArgs = append(localArgs, "--namespace", namespace)
}
}
return
}
Expand All @@ -274,6 +292,9 @@ func outputsString() string {
}

// formatContext returns a formated strings with the context has header, separated from the contents by a divider
func formatContext(context string, stdout []byte) string {
return fmt.Sprintf("\n%s\n%s\n%s", context, strings.Repeat("-", len(context)), string(stdout))
func formatContext(context string, namespace string, stdout []byte) string {
if namespace != "" {
namespace = ": " + namespace
}
return fmt.Sprintf("\n%s%s\n%s\n%s", context, namespace, strings.Repeat("-", len(context)+len(namespace)), string(stdout))
}
3 changes: 2 additions & 1 deletion pkg/mc/mc_helpers_test.go
View file
Original file line number Diff line number Diff line change
@@ -1,7 +1,8 @@
package mc

const (
context = "kind-kind"
context = "kind-kind"
namespace = "default"
)

var (
Expand Down
16 changes: 8 additions & 8 deletions pkg/mc/mc_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -93,7 +93,7 @@ coredns-66bff467f8-4lnsg 1/1 Running 1 22h
mc.getListContextsCmd = func() Cmd {
return m
}
mc.getKubectlCmd = func(args []string, context string) Cmd {
mc.getKubectlCmd = func(args []string, context string, namespace string) Cmd {
return m
}
b := bytes.NewBuffer([]byte(``))
Expand Down Expand Up @@ -173,9 +173,9 @@ func TestDo(t *testing.T) {
done := make(chan bool, 1)
var mutex = &sync.Mutex{}
output := map[string]json.RawMessage{}
do(done, context, output, false, nil, m, mutex)
do(done, context, namespace, output, false, nil, m, mutex)
assert.True(t, <-done)
assert.Equal(t, map[string]json.RawMessage{context: kubectlReturn}, output)
assert.Equal(t, map[string]json.RawMessage{context + ": " + namespace: kubectlReturn}, output)
}

func TestKubectl(t *testing.T) {
Expand Down Expand Up @@ -204,17 +204,17 @@ func TestGetLocalArgs(t *testing.T) {
}{
"default": {
args: []string{"get", "pods", "-n", "kube-system"},
want: []string{"get", "pods", "-n", "kube-system", "--context", context},
want: []string{"get", "pods", "-n", "kube-system", "--context", context, "--namespace", namespace},
},
"exec": {
args: []string{"exec", "deployment/local-path-provisioner", "-n", "local-path-storage", "-it", "--", "ls", "/usr"},
want: []string{"exec", "deployment/local-path-provisioner", "-n", "local-path-storage", "-it", "--context", context, "--", "ls", "/usr"},
want: []string{"exec", "deployment/local-path-provisioner", "-n", "local-path-storage", "-it", "--context", context, "--namespace", namespace, "--", "ls", "/usr"},
},
}

for name, test := range tests {
t.Run(name, func(t *testing.T) {
got := getLocalArgs(test.args, context)
got := getLocalArgs(test.args, context, namespace)
assert.Equal(t, test.want, got)
})
}
Expand All @@ -226,6 +226,6 @@ func TestOutputsString(t *testing.T) {
}

func TestFormatContext(t *testing.T) {
got := formatContext(context, kubectlReturn)
assert.Equal(t, "\nkind-kind\n---------\n"+string(kubectlReturn), got)
got := formatContext(context, namespace, kubectlReturn)
assert.Equal(t, "\nkind-kind: default\n------------------\n"+string(kubectlReturn), got)
}

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