fix: clarify what the dev docs install

On the dev docs, the Helm tab installs the latest release, but the
kubectl tab installs the main branch. Nothing on the page said
this, and Helm was the tab shown by default.

Add a note, and make both tabs link to each other, so a reader can
jump straight to the right one.

Signed-off-by: Marco Nenciarini <marco.nenciarini@enterprisedb.com>

web/docs/installation.mdx

@@ -59,10 +59,12 @@ import TabItem from '@theme/TabItem';
 import { InstallationSnippet, ManifestVersion } from '@site/src/components/Installation';
 import { HelmInstallationSnippet } from '@site/src/components/HelmInstallation';
 
-<Tabs groupId="install-method">
+<Tabs groupId="install-method" queryString>
   <TabItem value="helm" label="Helm Chart" default>
 
-The plugin can be installed using the provided [Helm chart](https://github.com/cloudnative-pg/charts/tree/main/charts/plugin-barman-cloud):
+The plugin can be installed using the provided [Helm chart](https://github.com/cloudnative-pg/charts/tree/main/charts/plugin-barman-cloud).
+This installs the latest published chart release; to test an unreleased
+development snapshot instead, switch to the [**Manifest (kubectl)**](./?install-method=kubectl#installing-the-barman-cloud-plugin) tab.
 
 <HelmInstallationSnippet />
 

web/src/components/HelmInstallation/index.tsx

@@ -1,22 +1,36 @@
-import { ReactElement } from "react";
-import CodeBlock from "@theme/CodeBlock";
+import {ReactElement} from 'react';
+import CodeBlock from '@theme/CodeBlock';
+import {useActiveVersion, useLatestVersion} from '@docusaurus/plugin-content-docs/client';
 
-type HelmInstallationProps = {
-  chartVersion?: string;
-};
-
-// HelmInstallationSnippet is the Helm incantation to install a specific
-// or latest available version of the Barman Cloud Plugin.
-export function HelmInstallationSnippet({
-  chartVersion,
-}: HelmInstallationProps): ReactElement<null> {
-  const versionArg = chartVersion ? `\n  --version ${chartVersion} \\` : "";
-  return (
-    <CodeBlock language="sh">
-      {`helm repo add cnpg https://cloudnative-pg.github.io/charts --force-update
+// HelmInstallationSnippet is the Helm command to install the plugin.
+//
+// - Latest release: no override. The chart already defaults to
+//   itself.
+// - Older release: pin image.tag and sidecarImage.tag to that
+//   version. We check this again on every build using
+//   useLatestVersion, so an old page updates itself once a newer
+//   version ships.
+// - Dev docs: also no override, but this does NOT install a dev
+//   build. Setting the tag alone would not be enough, since the
+//   chart's own templates (CRDs, RBAC...) can be older than what
+//   main needs. Use the kubectl method to test a dev build.
+export function HelmInstallationSnippet(): ReactElement<null> {
+    const activeVersion = useActiveVersion('default');
+    const latestVersion = useLatestVersion('default');
+    const isOlderRelease = activeVersion
+        && activeVersion.name !== 'current'
+        && activeVersion.name !== latestVersion.name;
+    const setArgs = isOlderRelease
+        ? ` \\
+  --set image.tag=v${activeVersion.name} \\
+  --set sidecarImage.tag=v${activeVersion.name}`
+        : '';
+    return (
+        <CodeBlock language="sh">
+            {`helm repo add cnpg https://cloudnative-pg.github.io/charts --force-update
 helm upgrade --install plugin-barman-cloud \\
-  --namespace cnpg-system \\${versionArg}
+  --namespace cnpg-system${setArgs} \\
   cnpg/plugin-barman-cloud`}
-    </CodeBlock>
-  );
+        </CodeBlock>
+    );
 }

web/src/components/Installation/index.tsx

@@ -1,5 +1,7 @@
 import {ReactElement} from 'react';
 import CodeBlock from '@theme/CodeBlock';
+import Link from '@docusaurus/Link';
+import {useLocation} from '@docusaurus/router';
 import {useActiveVersion} from '@docusaurus/plugin-content-docs/client';
 
 // DEV_MANIFEST_URL is the URL of the manifest.yaml on the main branch of the plugin repo.
@@ -31,14 +33,17 @@ export function ManifestVersion(): ReactElement<null> {
         : <>the latest development snapshot from the <code>main</code> branch</>;
 }
 
-// DevSnapshotSection offers the main-branch manifest as an alternative;
-// on the Dev docs the main install already is that manifest, so hide it.
+// DevSnapshotSection shows how to test the main-branch manifest. On
+// the Dev docs, the kubectl install above already does that, so we
+// hide this section there. (The Helm tab there installs the latest
+// release, not a dev build.)
 export function DevSnapshotSection(): ReactElement {
     const activeVersion = useActiveVersion('default');
+    const {pathname} = useLocation();
     if (!activeVersion || activeVersion.name === 'current') {
         return (
-            <p>The <a href="#installing-the-barman-cloud-plugin">install
-                command above</a> already applies the latest development
+            <p>The <Link to={`${pathname}?install-method=kubectl#installing-the-barman-cloud-plugin`}>kubectl
+                install command above</Link> already applies the latest development
                 snapshot from the <code>main</code> branch.</p>
         );
     }

web/versioned_docs/version-0.13.0/installation.mdx

@@ -64,7 +64,7 @@ import { HelmInstallationSnippet } from '@site/src/components/HelmInstallation';
 
 The plugin can be installed using the provided [Helm chart](https://github.com/cloudnative-pg/charts/tree/main/charts/plugin-barman-cloud):
 
-<HelmInstallationSnippet chartVersion="0.7.0" />
+<HelmInstallationSnippet />
 
 Example output:
 

web/versioned_docs/version-0.14.0/installation.mdx

@@ -64,7 +64,7 @@ import { HelmInstallationSnippet } from '@site/src/components/HelmInstallation';
 
 The plugin can be installed using the provided [Helm chart](https://github.com/cloudnative-pg/charts/tree/main/charts/plugin-barman-cloud):
 
-<HelmInstallationSnippet chartVersion="0.7.1" />
+<HelmInstallationSnippet />
 
 Example output: