feat(backend): remove the google books API key

.github/workflows/main.yml

@@ -179,7 +179,6 @@ jobs:
           APP_VERSION: ${{ steps.build.outputs.version }}
           DEFAULT_TMDB_ACCESS_TOKEN: ${{ secrets.DEFAULT_TMDB_ACCESS_TOKEN }}
           DEFAULT_MAL_CLIENT_ID: ${{ secrets.DEFAULT_MAL_CLIENT_ID }}
-          DEFAULT_GOOGLE_BOOKS_API_KEY: ${{ secrets.DEFAULT_GOOGLE_BOOKS_API_KEY }}
         run: |
           ${{ matrix.platform.command }} build --locked --target ${{ matrix.platform.target }} --release
       - name: Upload build artifact

Cross.toml

@@ -3,7 +3,6 @@ passthrough = [
     "APP_VERSION",
     "DEFAULT_TMDB_ACCESS_TOKEN",
     "DEFAULT_MAL_CLIENT_ID",
-    "DEFAULT_GOOGLE_BOOKS_API_KEY",
 ]
 
 [build]

crates/config/src/lib.rs

@@ -23,16 +23,6 @@ fn default_mal_client_id(_ctx: &()) -> Result<Option<String>, HandlerError> {
     Ok(Some(DEFAULT_MAL_CLIENT_ID.to_owned()))
 }
 
-#[cfg(debug_assertions)]
-pub const DEFAULT_GOOGLE_BOOKS_API_KEY: &str =
-    dotenvy_macro::dotenv!("DEFAULT_GOOGLE_BOOKS_API_KEY");
-#[cfg(not(debug_assertions))]
-pub const DEFAULT_GOOGLE_BOOKS_API_KEY: &str = env!("DEFAULT_GOOGLE_BOOKS_API_KEY");
-
-fn default_google_books_api_key(_ctx: &()) -> Result<Option<String>, HandlerError> {
-    Ok(Some(DEFAULT_GOOGLE_BOOKS_API_KEY.to_owned()))
-}
-
 #[derive(Debug, Serialize, Deserialize, Clone, Config)]
 #[config(rename_all = "snake_case", env_prefix = "ANIME_AND_MANGA_MAL_")]
 pub struct MalConfig {
@@ -123,7 +113,6 @@ pub struct OpenlibraryConfig {
 #[config(rename_all = "snake_case", env_prefix = "BOOKS_GOOGLE_BOOKS_")]
 pub struct GoogleBooksConfig {
     /// The API key to be used for the Google Books API.
-    #[setting(default = default_google_books_api_key)]
     pub api_key: String,
     /// Whether to pass the raw query string to the search API.
     pub pass_raw_query: bool,

docs/content/guides/books.md

@@ -0,0 +1,32 @@
+# Books
+
+A guide about books integration for Ryot.
+
+## Integration with Google Books
+
+Ryot also supports tracking books via [Google Books](https://books.google.com). However,
+the API is heavily rate limited, so it is not possible to hardcode the API keys in the
+application (unlike the others).
+
+You can follow the below steps to obtain your own API keys and enable book tracking with
+Google Books.
+
+### Steps
+
+1. Create a [Google Cloud Platform](https://cloud.google.com) account. Open your [Google
+   Cloud Platform Console](https://console.cloud.google.com).
+
+2. Use the default project or click on "Create a project" on the dashboard.
+
+3. Open the [APIs & Services Dashboard](https://console.cloud.google.com/apis/dashboard).
+
+4. Click on "Enable APIs and Services". Search for "Google Books API" and click on
+   "Enable".
+
+5. Click on "Credentials" on the left sidebar. Click on "Create Credentials" and select
+   "API key".
+
+6.  Click on "Create" and copy the API key.
+
+7. Set the `books.google_books.api_key` configuration variable in the environment as
+   described in the [configuration](../configuration.md#important-parameters) docs.