Minor bump changesets for all search plugins with upgrade instructions

Signed-off-by: Eric Peterson <ericpeterson@spotify.com>

.changeset/search-new-fantastic-pov.md

@@ -0,0 +1,76 @@
+---
+'@backstage/plugin-search-backend': minor
+'@backstage/plugin-search-backend-node': minor
+---
+
+This release represents a move out of a pre-alpha phase of the Backstage Search
+plugin, into an alpha phase. With this release, you gain more control over the
+layout of your search page on the frontend, as well as the ability to extend
+search on the backend to encompass everything Backstage users may want to find.
+
+If you are updating to version `v0.4.0` of `@backstage/plugin-search` from a
+prior release, you will need to make modifications to your app backend.
+
+First, navigate to your backend package and install the two related search
+backend packages:
+
+```sh
+cd packages/backend
+yarn add @backstage/plugin-search-backend @backstage/plugin-search-backend-node
+```
+
+Wire up these new packages into your app backend by first creating a new
+`search.ts` file at `src/plugins/search.ts` with contents like the following:
+
+```typescript
+import { useHotCleanup } from '@backstage/backend-common';
+import { createRouter } from '@backstage/plugin-search-backend';
+import {
+  IndexBuilder,
+  LunrSearchEngine,
+} from '@backstage/plugin-search-backend-node';
+import { PluginEnvironment } from '../types';
+import { DefaultCatalogCollator } from '@backstage/plugin-catalog-backend';
+
+export default async function createPlugin({
+  logger,
+  discovery,
+}: PluginEnvironment) {
+  // Initialize a connection to a search engine.
+  const searchEngine = new LunrSearchEngine({ logger });
+  const indexBuilder = new IndexBuilder({ logger, searchEngine });
+
+  // Collators are responsible for gathering documents known to plugins. This
+  // particular collator gathers entities from the software catalog.
+  indexBuilder.addCollator({
+    defaultRefreshIntervalSeconds: 600,
+    collator: new DefaultCatalogCollator({ discovery }),
+  });
+
+  // The scheduler controls when documents are gathered from collators and sent
+  // to the search engine for indexing.
+  const { scheduler } = await indexBuilder.build();
+
+  // A 3 second delay gives the backend server a chance to initialize before
+  // any collators are executed, which may attempt requests against the API.
+  setTimeout(() => scheduler.start(), 3000);
+  useHotCleanup(module, () => scheduler.stop());
+
+  return await createRouter({
+    engine: indexBuilder.getSearchEngine(),
+    logger,
+  });
+}
+```
+
+Then, ensure the search plugin you configured above is initialized by modifying
+your backend's `index.ts` file in the following ways:
+
+```diff
++import search from './plugins/search';
+// ...
++const searchEnv = useHotMemoize(module, () => createEnv('search'));
+// ...
++apiRouter.use('/search', await search(searchEnv));
+// ...
+```

.changeset/search-whole-new-world.md

@@ -0,0 +1,118 @@
+---
+'@backstage/plugin-search': minor
+---
+
+This release represents a move out of a pre-alpha phase of the Backstage Search
+plugin, into an alpha phase. With this release, you gain more control over the
+layout of your search page on the frontend, as well as the ability to extend
+search on the backend to encompass everything Backstage users may want to find.
+
+If you are updating to this version of `@backstage/plugin-search` from a prior
+release, you will need to make the following modifications to your App:
+
+In your app package, create a new `searchPage` component at, for example,
+`packages/app/src/components/search/SearchPage.tsx` with contents like the
+following:
+
+```tsx
+import React from 'react';
+import { makeStyles, Theme, Grid, List, Paper } from '@material-ui/core';
+
+import { Content, Header, Lifecycle, Page } from '@backstage/core';
+import { CatalogResultListItem } from '@backstage/plugin-catalog';
+import {
+  SearchBar,
+  SearchFilter,
+  SearchResult,
+  DefaultResultListItem,
+} from '@backstage/plugin-search';
+
+const useStyles = makeStyles((theme: Theme) => ({
+  bar: {
+    padding: theme.spacing(1, 0),
+  },
+  filters: {
+    padding: theme.spacing(2),
+  },
+  filter: {
+    '& + &': {
+      marginTop: theme.spacing(2.5),
+    },
+  },
+}));
+
+const SearchPage = () => {
+  const classes = useStyles();
+
+  return (
+    <Page themeId="home">
+      <Header title="Search" subtitle={<Lifecycle alpha />} />
+      <Content>
+        <Grid container direction="row">
+          <Grid item xs={12}>
+            <Paper className={classes.bar}>
+              <SearchBar debounceTime={100} />
+            </Paper>
+          </Grid>
+          <Grid item xs={3}>
+            <Paper className={classes.filters}>
+              <SearchFilter.Select
+                className={classes.filter}
+                name="kind"
+                values={['Component', 'Template']}
+              />
+              <SearchFilter.Checkbox
+                className={classes.filter}
+                name="lifecycle"
+                values={['experimental', 'production']}
+              />
+            </Paper>
+          </Grid>
+          <Grid item xs={9}>
+            <SearchResult>
+              {({ results }) => (
+                <List>
+                  {results.map(({ type, document }) => {
+                    switch (type) {
+                      case 'software-catalog':
+                        return (
+                          <CatalogResultListItem
+                            key={document.location}
+                            result={document}
+                          />
+                        );
+                      default:
+                        return (
+                          <DefaultResultListItem
+                            key={document.location}
+                            result={document}
+                          />
+                        );
+                    }
+                  })}
+                </List>
+              )}
+            </SearchResult>
+          </Grid>
+        </Grid>
+      </Content>
+    </Page>
+  );
+};
+
+export const searchPage = <SearchPage />;
+```
+
+Then in `App.tsx`, import this new `searchPage` component, and set it as a
+child of the existing `<SearchPage />` route so that it looks like this:
+
+```tsx
+import { searchPage } from './components/search/SearchPage';
+// ...
+<Route path="/search" element={<SearchPage />}>
+  {searchPage}
+</Route>;
+```
+
+You will also need to update your backend. For details, check the changeset for
+`v0.2.0` of `@backstage/plugin-search-backend`.