feat(exec): add --target flag in exec command

introduces a flag --target in exec command. This is useful when a
Deploy action consists of multiple underlying components and user
wants to target a specific one. At the moment, this flag is only
supported for kubernetes-exec and container-exec.

When a pod has multiple containers, user can use target flag to exec
into a specific container. Additionally, if no container name is
provided, it respects the annotation kubectl.kubernetes.io/default-container
and defaults to that container.

The existing behavior is still the default: it picks the first container
in Pod.

core/src/commands/exec.ts

@@ -16,6 +16,7 @@ import { executeAction } from "../graph/actions"
 import { NotFoundError } from "../exceptions"
 import { DeployStatus } from "../plugin/handlers/Deploy/get-status"
 import { createActionLog } from "../logger/log-entry"
+import { K8_POD_DEFAULT_CONTAINER_ANNOTATION_KEY } from "../plugins/kubernetes/run"
 
 const execArgs = {
   deploy: new StringParameter({
@@ -40,6 +41,12 @@ const execOpts = {
     cliDefault: true,
     cliOnly: true,
   }),
+  target: new StringParameter({
+    help: `Specify name of the target if a Deploy action consists of multiple components. _NOTE: This option is only relevant in certain scenarios and will be ignored otherwise._ For Kubernetes deploy actions, this is useful if a Deployment includes multiple containers, such as sidecar containers. By default, the container with \`${K8_POD_DEFAULT_CONTAINER_ANNOTATION_KEY}\` annotation or the first container is picked.`,
+    cliOnly: true,
+    defaultValue: undefined,
+    required: false,
+  }),
 }
 
 type Args = typeof execArgs
@@ -74,6 +81,7 @@ export class ExecCommand extends Command<Args, Opts> {
   async action({ garden, log, args, opts }: CommandParams<Args, Opts>): Promise<CommandResult<ExecInDeployResult>> {
     const deployName = args.deploy
     const command = this.getCommand(args)
+    const target = opts["target"] as string | undefined
 
     const graph = await garden.getConfigGraph({ log, emit: false })
     const action = graph.getDeploy(deployName)
@@ -138,6 +146,7 @@ export class ExecCommand extends Command<Args, Opts> {
       graph,
       action: executed,
       command,
+      target,
       interactive: opts.interactive,
     })
 

core/src/plugin/handlers/Deploy/exec.ts

@@ -16,6 +16,7 @@ import { Executed } from "../../../actions/types"
 interface ExecInDeployParams<T extends DeployAction> extends PluginDeployActionParamsBase<T> {
   command: string[]
   interactive: boolean
+  target?: string
 }
 
 export interface ExecInDeployResult {

core/src/plugins/kubernetes/container/exec.ts

@@ -16,7 +16,7 @@ import { DeployActionHandler } from "../../../plugin/action-types"
 import { k8sGetContainerDeployStatus } from "./status"
 
 export const execInContainer: DeployActionHandler<"exec", ContainerDeployAction> = async (params) => {
-  const { ctx, log, action, command, interactive } = params
+  const { ctx, log, action, command, interactive, target: containerName } = params
   const k8sCtx = <KubernetesPluginContext>ctx
   const provider = k8sCtx.provider
   const status = await k8sGetContainerDeployStatus({
@@ -43,6 +43,7 @@ export const execInContainer: DeployActionHandler<"exec", ContainerDeployAction>
     log,
     namespace,
     workload: status.detail?.detail.workload,
+    containerName,
     command,
     interactive,
   })

core/src/plugins/kubernetes/kubernetes-type/common.ts

@@ -52,7 +52,7 @@ export async function getManifests({
 
   // remove *List objects
   const manifests = rawManifests.flatMap((manifest) => {
-    if (manifest.kind.endsWith("List")) {
+    if (manifest?.kind?.endsWith("List")) {
       if (!manifest.items || manifest.items.length === 0) {
         // empty list
         return []

core/src/plugins/kubernetes/kubernetes-type/exec.ts

@@ -17,7 +17,7 @@ import { getKubernetesDeployStatus } from "./handlers"
 import chalk from "chalk"
 
 export const execInKubernetesDeploy: DeployActionHandler<"exec", KubernetesDeployAction> = async (params) => {
-  const { ctx, log, action, command, interactive } = params
+  const { ctx, log, action, command, interactive, target: containerName } = params
   const k8sCtx = <KubernetesPluginContext>ctx
   const provider = k8sCtx.provider
 
@@ -64,5 +64,5 @@ export const execInKubernetesDeploy: DeployActionHandler<"exec", KubernetesDeplo
     })
   }
 
-  return execInWorkload({ ctx, provider, log, namespace, workload: target, command, interactive })
+  return execInWorkload({ ctx, provider, log, namespace, workload: target, containerName, command, interactive })
 }

core/src/plugins/kubernetes/run.ts

@@ -46,6 +46,9 @@ import { LogLevel } from "../../logger/logger"
 import { getResourceEvents } from "./status/events"
 import stringify from "json-stringify-safe"
 
+// ref: https://kubernetes.io/docs/reference/labels-annotations-taints/#kubectl-kubernetes-io-default-container
+export const K8_POD_DEFAULT_CONTAINER_ANNOTATION_KEY = "kubectl.kubernetes.io/default-container"
+
 /**
  * When a `podSpec` is passed to `runAndCopy`, only these fields will be used for the runner's pod spec
  * (and, in some cases, overridden/populated in `runAndCopy`).
@@ -1047,7 +1050,29 @@ export class PodRunner extends PodRunnerParams {
     }
 
     const startedAt = new Date()
-    const containerName = container || this.pod.spec.containers[0].name
+    let containerName = container
+    if (!containerName) {
+      // if no container name is specified, check if the Pod has annotation kubectl.kubernetes.io/default-container
+      const defaultAnnotationContainer = this.pod.metadata.annotations
+        ? this.pod.metadata.annotations[K8_POD_DEFAULT_CONTAINER_ANNOTATION_KEY]
+        : undefined
+
+      if (defaultAnnotationContainer) {
+        containerName = defaultAnnotationContainer
+        if (this.pod.spec.containers.length > 1) {
+          log.info(
+            // in case there are more than 1 containers and exec picks container with annotation
+            `Defaulted container ${containerName} due to the annotation ${K8_POD_DEFAULT_CONTAINER_ANNOTATION_KEY}.`
+          )
+        }
+      } else {
+        containerName = this.pod.spec.containers[0].name
+        if (this.pod.spec.containers.length > 1) {
+          const allContainerNames = this.pod.spec.containers.map((c) => c.name)
+          log.info(`Defaulted container ${containerName} out of: ${allContainerNames.join(", ")}.`)
+        }
+      }
+    }
 
     log.debug(`Execing command in ${this.namespace}/Pod/${this.podName}/${containerName}: ${command.join(" ")}`)
     const startTime = new Date(Date.now())

core/src/plugins/kubernetes/util.ts

@@ -252,6 +252,7 @@ export async function execInWorkload({
   namespace,
   workload,
   command,
+  containerName,
   streamLogs = false,
   interactive,
 }: {
@@ -261,6 +262,7 @@ export async function execInWorkload({
   namespace: string
   workload: KubernetesWorkload | KubernetesPod
   command: string[]
+  containerName?: string
   streamLogs?: boolean
   interactive: boolean
 }) {
@@ -285,6 +287,7 @@ export async function execInWorkload({
     timeoutSec: 999999,
     tty: interactive,
     buffer: true,
+    containerName,
   }
 
   if (streamLogs) {

core/test/unit/src/commands/exec.ts

@@ -27,6 +27,7 @@ describe("ExecCommand", () => {
       args,
       opts: withDefaultGlobalOpts({
         interactive: false,
+        target: "",
       }),
     })
 

docs/reference/commands.md

@@ -1361,6 +1361,7 @@ Examples:
 | Argument | Alias | Type | Description |
 | -------- | ----- | ---- | ----------- |
   | `--interactive` |  | boolean | Set to false to skip interactive mode and just output the command result
+  | `--target` |  | string | Specify name of the target if a Deploy action consists of multiple components. _NOTE: This option is only relevant in certain scenarios and will be ignored otherwise._ For Kubernetes deploy actions, this is useful if a Deployment includes multiple containers, such as sidecar containers. By default, the container with `kubectl.kubernetes.io/default-container` annotation or the first container is picked.
 
 #### Outputs