[Upgrade Assistant] Make infra plugin optional

x-pack/plugins/upgrade_assistant/__jest__/client_integration/helpers/app_context.mock.ts

@@ -74,6 +74,7 @@ export const getAppContextMock = () => ({
   },
   plugins: {
     share: shareMock,
+    infra: undefined,
     cloud: {
       ...cloudMock.createSetup(),
       isCloudEnabled: false,

x-pack/plugins/upgrade_assistant/__jest__/client_integration/overview/fix_logs_step/fix_logs_step.test.tsx

@@ -198,6 +198,9 @@ describe('Overview - Fix deprecation logs step', () => {
               prepend: (url: string) => url,
             },
           },
+          plugins: {
+            infra: {},
+          },
         });
       });
 
@@ -211,6 +214,14 @@ describe('Overview - Fix deprecation logs step', () => {
       );
     });
 
+    test(`Doesn't show observability app link if infra app is not available`, async () => {
+      const { component, exists } = testBed;
+
+      component.update();
+
+      expect(exists('viewObserveLogs')).toBe(false);
+    });
+
     test('Has a link to see logs in discover app', async () => {
       await act(async () => {
         testBed = await setupOverviewPage();

x-pack/plugins/upgrade_assistant/kibana.json

@@ -8,7 +8,7 @@
     "githubTeam": "kibana-stack-management"
   },
   "configPath": ["xpack", "upgrade_assistant"],
-  "requiredPlugins": ["management", "data", "licensing", "features", "infra", "share"],
-  "optionalPlugins": ["usageCollection", "cloud"],
+  "requiredPlugins": ["management", "data", "licensing", "features", "share"],
+  "optionalPlugins": ["usageCollection", "cloud", "infra"],
   "requiredBundles": ["esUiShared", "kibanaReact", "kibanaUtils"]
 }

x-pack/plugins/upgrade_assistant/public/application/components/overview/fix_logs_step/external_links.tsx

@@ -105,22 +105,26 @@ const ObservabilityAppLink: FunctionComponent<Props> = ({ checkpoint }) => {
 };
 
 export const ExternalLinks: FunctionComponent<Props> = ({ checkpoint }) => {
+  const { infra: hasInfraPlugin } = useAppContext().plugins;
+
   return (
     <EuiFlexGroup>
-      <EuiFlexItem>
-        <EuiPanel>
-          <EuiText size="s">
-            <p>
-              <FormattedMessage
-                id="xpack.upgradeAssistant.overview.observe.observabilityDescription"
-                defaultMessage="Get insight into which deprecated APIs are being used and what applications you need to update."
-              />
-            </p>
-          </EuiText>
-          <EuiSpacer size="m" />
-          <ObservabilityAppLink checkpoint={checkpoint} />
-        </EuiPanel>
-      </EuiFlexItem>
+      {hasInfraPlugin && (
+        <EuiFlexItem>
+          <EuiPanel>
+            <EuiText size="s">
+              <p>
+                <FormattedMessage
+                  id="xpack.upgradeAssistant.overview.observe.observabilityDescription"
+                  defaultMessage="Get insight into which deprecated APIs are being used and what applications you need to update."
+                />
+              </p>
+            </EuiText>
+            <EuiSpacer size="m" />
+            <ObservabilityAppLink checkpoint={checkpoint} />
+          </EuiPanel>
+        </EuiFlexItem>
+      )}
       <EuiFlexItem>
         <EuiPanel>
           <EuiText size="s">

x-pack/plugins/upgrade_assistant/public/plugin.ts

@@ -42,7 +42,7 @@ export class UpgradeAssistantUIPlugin
       title: pluginName,
       order: 1,
       async mount(params) {
-        const [coreStart, { data }] = await coreSetup.getStartServices();
+        const [coreStart, { data, ...plugins }] = await coreSetup.getStartServices();
 
         const {
           chrome: { docTitle },
@@ -56,6 +56,10 @@ export class UpgradeAssistantUIPlugin
           plugins: {
             cloud,
             share,
+            // Infra plugin doesnt export anything as a public interface. So the only
+            // way we have at this stage for checking if the plugin is available or not
+            // is by checking if the startServices has the `infra` key.
+            infra: plugins.hasOwnProperty('infra') ? {} : undefined,
           },
           services: {
             core: coreStart,

x-pack/plugins/upgrade_assistant/public/types.ts

@@ -38,6 +38,7 @@ export interface AppDependencies {
   plugins: {
     cloud?: CloudSetup;
     share: SharePluginSetup;
+    infra: object | undefined;
   };
   services: {
     core: CoreStart;

x-pack/plugins/upgrade_assistant/server/plugin.ts

@@ -94,7 +94,7 @@ export class UpgradeAssistantServerPlugin implements Plugin {
 
     // We need to initialize the deprecation logs plugin so that we can
     // navigate from this app to the observability app using a source_id.
-    infra.defineInternalSourceConfiguration(DEPRECATION_LOGS_SOURCE_ID, {
+    infra?.defineInternalSourceConfiguration(DEPRECATION_LOGS_SOURCE_ID, {
       name: 'deprecationLogs',
       description: 'deprecation logs',
       logIndices: {