ShellEnv extension api (#4802)

* adding extension api for terminal environment variables

Signed-off-by: Jim Ehrismann <jehrismann@mirantis.com>

* modified shell env api to work as a transformer (WIP)

Signed-off-by: Jim Ehrismann <jehrismann@mirantis.com>

* address some review comments

Signed-off-by: Jim Ehrismann <jehrismann@mirantis.com>

* shell env modifiers now take a CatalogEntity in ShellEnvContext param

Signed-off-by: Jim Ehrismann <jehrismann@mirantis.com>

* tweaks and bug fix

Signed-off-by: Jim Ehrismann <jehrismann@mirantis.com>

* refactored to remove ShellEnvModifier code from shell-session to local-shell-session

Signed-off-by: Jim Ehrismann <jehrismann@mirantis.com>

* further refactoring and documentation

Signed-off-by: Jim Ehrismann <jehrismann@mirantis.com>

* added comment

Signed-off-by: Jim Ehrismann <jehrismann@mirantis.com>

src/extensions/common-api/registrations.ts

@@ -11,3 +11,4 @@ export type { PageRegistration, RegisteredPage, PageParams, PageComponentProps,
 export type { ClusterPageMenuRegistration, ClusterPageMenuComponents } from "../registries/page-menu-registry";
 export type { ProtocolHandlerRegistration, RouteParams as ProtocolRouteParams, RouteHandler as ProtocolRouteHandler } from "../registries/protocol-handler";
 export type { CustomCategoryViewProps, CustomCategoryViewComponents, CustomCategoryViewRegistration } from "../../renderer/components/+catalog/custom-views";
+export type { ShellEnvModifier, ShellEnvContext } from "../../main/shell-session/shell-env-modifier/shell-env-modifier-registration";

src/extensions/lens-main-extension.ts

@@ -10,10 +10,27 @@ import type { CatalogEntity } from "../common/catalog";
 import type { IObservableArray } from "mobx";
 import type { MenuRegistration } from "../main/menu/menu-registration";
 import type { TrayMenuRegistration } from "../main/tray/tray-menu-registration";
+import type { ShellEnvModifier } from "../main/shell-session/shell-env-modifier/shell-env-modifier-registration";
+
 export class LensMainExtension extends LensExtension {
   appMenus: MenuRegistration[] = [];
   trayMenus: TrayMenuRegistration[] = [];
 
+  /**
+   * implement this to modify the shell environment that Lens terminals are opened with. The ShellEnvModifier type has the signature
+   * 
+   * (ctx: ShellEnvContext, env: Record<string, string | undefined>) => Record<string, string | undefined>
+   * 
+   *  @param ctx the shell environment context, specifically the relevant catalog entity for the terminal. This can be used, for example, to get
+   * cluster-specific information that can be made available in the shell environment by the implementation of terminalShellEnvModifier
+   * 
+   * @param env the current shell environment that the terminal will be opened with. The implementation should modify this as desired.
+   * 
+   * @returns the modified shell environment that the terminal will be opened with. The implementation must return env as passed in, if it
+   * does not modify the shell environment
+   */
+  terminalShellEnvModifier?: ShellEnvModifier;
+
   async navigate(pageId?: string, params?: Record<string, any>, frameId?: number) {
     return WindowManager.getInstance().navigateExtension(this.id, pageId, params, frameId);
   }

src/main/shell-session/local-shell-session/local-shell-session.injectable.ts

@@ -7,6 +7,7 @@ import { LocalShellSession } from "./local-shell-session";
 import type { Cluster } from "../../../common/cluster/cluster";
 import type WebSocket from "ws";
 import createKubectlInjectable from "../../kubectl/create-kubectl.injectable";
+import terminalShellEnvModifiersInjectable from "../shell-env-modifier/terminal-shell-env-modify.injectable";
 
 interface InstantiationParameter {
   webSocket: WebSocket;
@@ -17,10 +18,11 @@ interface InstantiationParameter {
 const localShellSessionInjectable = getInjectable({
   instantiate: (di, { cluster, tabId, webSocket }: InstantiationParameter) => {
     const createKubectl = di.inject(createKubectlInjectable);
+    const localShellEnvModify = di.inject(terminalShellEnvModifiersInjectable);
 
     const kubectl = createKubectl(cluster.version);
 
-    return new LocalShellSession(kubectl, webSocket, cluster, tabId);
+    return new LocalShellSession(localShellEnvModify, kubectl, webSocket, cluster, tabId);
   },
 
   lifecycle: lifecycleEnum.transient,

src/main/shell-session/local-shell-session/local-shell-session.ts

@@ -3,14 +3,22 @@
  * Licensed under MIT License. See LICENSE in root directory for more information.
  */
 
+import type WebSocket from "ws";
 import path from "path";
 import { helmCli } from "../../helm/helm-cli";
 import { UserStore } from "../../../common/user-store";
+import type { Cluster } from "../../../common/cluster/cluster";
+import type { ClusterId } from "../../../common/cluster-types";
 import { ShellSession } from "../shell-session";
+import type { Kubectl } from "../../kubectl/kubectl";
 
 export class LocalShellSession extends ShellSession {
   ShellType = "shell";
 
+  constructor(protected shellEnvModify: (clusterId: ClusterId, env: Record<string, string>) => Record<string, string>, kubectl: Kubectl, websocket: WebSocket, cluster: Cluster, terminalId: string) {
+    super(kubectl, websocket, cluster, terminalId);
+  }
+  
   protected getPathEntries(): string[] {
     return [helmCli.getBinaryDir()];
   }
@@ -20,7 +28,11 @@ export class LocalShellSession extends ShellSession {
   }
 
   public async open() {
-    const env = await this.getCachedShellEnv();
+    let env = await this.getCachedShellEnv();
+
+    // extensions can modify the env
+    env = this.shellEnvModify(this.cluster.id, env);
+
     const shell = env.PTYSHELL;
     const args = await this.getShellArgs(shell);
 

src/main/shell-session/shell-env-modifier/shell-env-modifier-registration.ts

@@ -0,0 +1,12 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+
+import type { CatalogEntity } from "../../../common/catalog";
+
+export interface ShellEnvContext {
+  catalogEntity: CatalogEntity;
+}
+
+export type ShellEnvModifier = (ctx: ShellEnvContext, env: Record<string, string | undefined>) => Record<string, string | undefined>;

src/main/shell-session/shell-env-modifier/terminal-shell-env-modifiers.ts

@@ -0,0 +1,39 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+
+import { computed, IComputedValue } from "mobx";
+import type { ClusterId } from "../../../common/cluster-types";
+import type { LensMainExtension } from "../../../extensions/lens-main-extension";
+import { catalogEntityRegistry } from "../../catalog";
+ 
+interface Dependencies {
+  extensions: IComputedValue<LensMainExtension[]>;
+}
+ 
+export const terminalShellEnvModify = ({ extensions }: Dependencies) => 
+  (clusterId: ClusterId, env: Record<string, string>) => {
+    const terminalShellEnvModifiers = computed(() => (
+      extensions.get()
+        .map((extension) => extension.terminalShellEnvModifier)
+        .filter(Boolean)
+    ))
+      .get();
+
+    if (terminalShellEnvModifiers.length === 0) {
+      return env;
+    }
+
+    const entity = catalogEntityRegistry.getById(clusterId);
+
+    if (entity) {
+      const ctx = { catalogEntity: entity };
+
+      // clone it so the passed value is not also modified
+      env = JSON.parse(JSON.stringify(env));
+      env = terminalShellEnvModifiers.reduce((env, modifier) => modifier(ctx, env), env);
+    }
+
+    return env;
+  };

src/main/shell-session/shell-env-modifier/terminal-shell-env-modify.injectable.ts

@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+
+import { getInjectable, lifecycleEnum } from "@ogre-tools/injectable";
+import mainExtensionsInjectable from "../../../extensions/main-extensions.injectable";
+import { terminalShellEnvModify } from "./terminal-shell-env-modifiers";
+ 
+const terminalShellEnvModifyInjectable = getInjectable({
+  instantiate: (di) =>
+    terminalShellEnvModify({
+      extensions: di.inject(mainExtensionsInjectable),
+    }),
+ 
+  lifecycle: lifecycleEnum.singleton,
+});
+ 
+export default terminalShellEnvModifyInjectable;