Support for specifying the URL on the command line

src/api.rs

@@ -15,8 +15,8 @@
  */
 
 use serde::Deserialize;
+use url::Url;
 
-use crate::config::Config;
 use crate::error::ApiError;
 
 /// Iterate over a paginated result set, collecting and returning the response
@@ -37,7 +37,7 @@ use crate::error::ApiError;
 /// error deserializing the HTTP response body as JSON, or if there is an
 /// error parsing the `Link` header value as an RFC5988 URL.
 pub async fn fetch_all<T: for<'de> Deserialize<'de>>(
-    config: &Config,
+    base: &Url,
     path: &str,
 ) -> Result<Vec<T>, ApiError> {
     log::trace!("fetch_all({path:?})");
@@ -46,7 +46,7 @@ pub async fn fetch_all<T: for<'de> Deserialize<'de>>(
     let mut path = String::from(path);
     loop {
         log::debug!("GET {path:?}");
-        let url = config.registry_url.join(&path)?;
+        let url = base.join(&path)?;
 
         let resp = reqwest::get(url).await?;
         let headers = resp.headers().clone();

src/cli.rs

@@ -47,6 +47,9 @@ pub(crate) struct Cli {
     value_enum
     )]
     pub log_level: LogLevel,
+
+    /// The host or host:port for the Docker Registry
+    pub registry: String,
 }
 
 #[derive(ValueEnum, Copy, Clone, Debug, PartialEq, Eq)]

src/commands.rs

@@ -15,9 +15,9 @@
  */
 
 use serde::Deserialize;
+use url::Url;
 
 use crate::api;
-use crate::config::Config;
 use crate::error::ApiError;
 
 /// Handler for the `Catalog` endpoint
@@ -29,7 +29,7 @@ use crate::error::ApiError;
 ///
 /// Returns an `ApiError` if there is a problem fetching or parsing the
 /// responses from the Docker Registry API.  
-pub async fn catalog_handler(config: &Config) -> Result<(), ApiError> {
+pub async fn catalog_handler(registry_url: &Url) -> Result<(), ApiError> {
     #[derive(Deserialize)]
     struct Response {
         repositories: Vec<String>,
@@ -38,7 +38,7 @@ pub async fn catalog_handler(config: &Config) -> Result<(), ApiError> {
     log::trace!("catalog_handler()");
     let path = "v2/_catalog";
 
-    let responses: Vec<Response> = api::fetch_all(config, path).await?;
+    let responses: Vec<Response> = api::fetch_all(registry_url, path).await?;
     let repository_list: Vec<&str> = responses
         .iter()
         .flat_map(|r| r.repositories.iter().map(String::as_str))
@@ -60,7 +60,7 @@ pub async fn catalog_handler(config: &Config) -> Result<(), ApiError> {
 ///
 /// Returns an `ApiError` if there is a problem fetching or parsing the
 /// responses from the Docker Registry API.  
-pub async fn tags_handler(config: &Config, name: &str) -> Result<(), ApiError> {
+pub async fn tags_handler(registry_url: &Url, name: &str) -> Result<(), ApiError> {
     #[derive(Deserialize)]
     struct Response {
         tags: Vec<String>,
@@ -69,7 +69,7 @@ pub async fn tags_handler(config: &Config, name: &str) -> Result<(), ApiError> {
     log::trace!("tags_handler(name: {name})");
     let path = format!("/v2/{name}/tags/list");
 
-    let responses: Vec<Response> = api::fetch_all(config, &path).await?;
+    let responses: Vec<Response> = api::fetch_all(registry_url, &path).await?;
     let tag_list: Vec<&str> = responses
         .iter()
         .flat_map(|r| r.tags.iter().map(String::as_str))
@@ -89,11 +89,10 @@ pub async fn tags_handler(config: &Config, name: &str) -> Result<(), ApiError> {
 /// Returns an `ApiError` if there is a problem fetching the manifest or if there
 /// is a problem parsing the response from the Docker Registry API.
 #[allow(clippy::unused_async)]
-pub async fn show_handler(config: &Config, image: &str, tag: &str) -> Result<(), ApiError> {
+pub async fn show_handler(registry_url: &Url, image: &str, tag: &str) -> Result<(), ApiError> {
     log::trace!("show_handler(image: {image}, tag: {tag})");
-    let base = config.registry_url.clone();
     let path = format!("/v2/{image}/manifests/{tag}");
-    let _url = base.join(&path)?;
+    let _url = registry_url.join(&path)?;
     Ok(())
 }
 
@@ -105,7 +104,7 @@ pub async fn show_handler(config: &Config, image: &str, tag: &str) -> Result<(),
 /// manifest digest, or if there is a problem deleting the manifest from the
 /// Docker Registry API.
 #[allow(clippy::unused_async)]
-pub async fn delete_handler(_config: &Config, image: &str, tag: &str) -> Result<(), ApiError> {
+pub async fn delete_handler(_registry_url: &Url, image: &str, tag: &str) -> Result<(), ApiError> {
     log::trace!("delete_handler(image: {image}, tag: {tag})");
     todo!()
 }
@@ -118,12 +117,11 @@ pub async fn delete_handler(_config: &Config, image: &str, tag: &str) -> Result<
 ///
 /// Returns an `ApiError` if there is a problem communicating with the
 /// endpoint or if the required version is not supported.
-pub async fn check_handler(config: &Config) -> Result<(), ApiError> {
+pub async fn check_handler(registry_url: &Url) -> Result<(), ApiError> {
     log::trace!("check_handler()");
 
-    let base = config.registry_url.clone();
     let path = "/v2";
-    let url = base.join(path)?;
+    let url = registry_url.join(path)?;
 
     let response = reqwest::get(url).await?;
 

src/error.rs

@@ -28,6 +28,10 @@ pub enum DredgeError {
     /// An error communicating with the Registry API
     #[error(transparent)]
     ApiError(#[from] ApiError),
+
+    /// An error building the registry URL
+    #[error("Error determining registry URL from {0}")]
+    RegistryUrlError(String),
 }
 
 /// An error related to the configuration fo the program.

src/main.rs

@@ -16,15 +16,12 @@
 
 #![deny(clippy::pedantic)]
 
-use std::ffi::OsString;
-use std::path::PathBuf;
-
 use clap::Parser;
+use url::Url;
 
 use crate::cli::Cli;
 use crate::cli::Commands;
-use crate::config::Config;
-use crate::error::ConfigError;
+
 use crate::error::DredgeError;
 
 mod api;
@@ -33,55 +30,27 @@ mod commands;
 mod config;
 mod error;
 
-/// The default basename of the main configuration file.
-const CONFIG_FILE_NAME: &str = "dredge.toml";
-
-/// The XDG directory prefix.
-const CONFIG_PREFIX: &str = "dredge";
-
-/// Locate the absolute path to the saved configuration file on disk.
+/// Generate the full Docker Registry URL from a given `host[:port]`
 ///
-/// If given an optional `path` to a configuration file, and that file
-/// exists on disk, the absolute path to that file will be returned.
-/// Otherwise, the XDG configuration path will be used.  If neither the
-/// optional `path` parameter refers to an existing file on disk, nor a
-/// suitable configuration file can be located within the XDG configuration
-/// path, the `None` variant will be returned.
-fn locate_config_file(path: Option<OsString>) -> Option<PathBuf> {
-    log::trace!("locate_config_file({path:?})");
-
-    if let Some(path) = path {
-        let p = PathBuf::from(path);
-        log::debug!("Checking if path {p:?} exists");
-        p.try_exists().map(|_| Some(p)).unwrap_or(None)
-    } else {
-        let xdg_dirs = xdg::BaseDirectories::with_prefix(CONFIG_PREFIX).ok()?;
-        let search_paths: Vec<PathBuf> = vec![xdg_dirs.get_config_home()]
-            .into_iter()
-            .chain(xdg_dirs.get_config_dirs())
-            .collect();
-        log::debug!("Searching configuration directories for {CONFIG_FILE_NAME} {search_paths:?}");
-        xdg_dirs.find_config_file(CONFIG_FILE_NAME)
-    }
-}
-
-/// Attempt to create a default configuration file in the XDG configuration
-/// path.  Any sub-directories of the XDG configuration path which do not
-/// already exist will be created automatically.
+/// This prepends the HTTPS scheme and converts the given string to a `Url`
+/// instance.
+///
+/// If the given `host` value is already a valid URL, then it will be returned
+/// as-is.
 ///
 /// # Errors:
 ///
-/// This returns a `ConfigError` if a problem occurred which prevented either
-/// the creation of the directory tree, or in writing the default configuration
-/// to the file.
-fn create_default_config_file() -> Result<PathBuf, ConfigError> {
-    log::trace!("create_default_config_file()");
+/// If there is a problem parsing the resulting string as a valid URL, a
+/// `DredgeError::RegistryUrlError` will be returned.
+fn make_registry_url(host: &str) -> Result<Url, DredgeError> {
+    log::trace!("make_registry_url(host: {host})");
 
-    let xdg_dirs = xdg::BaseDirectories::with_prefix(CONFIG_PREFIX)?;
-    let config_path = xdg_dirs.place_config_file(CONFIG_FILE_NAME)?;
-    let default_config = toml::to_string_pretty(&Config::default())?;
-    std::fs::write(&config_path, default_config)?;
-    Ok(config_path)
+    Url::parse(host)
+        .or_else(|_| {
+            let url_string = format!("https://{host}");
+            Url::parse(&url_string)
+        })
+        .or(Err(DredgeError::RegistryUrlError(host.to_string())))
 }
 
 #[async_std::main]
@@ -92,20 +61,20 @@ async fn main() -> Result<(), DredgeError> {
     let log_level = args.log_level;
     femme::with_level(log::LevelFilter::from(log_level));
 
-    // -- Load and parse configuration file
-    let config_file =
-        locate_config_file(args.config).map_or_else(create_default_config_file, Ok)?;
-    log::debug!("Using configuration file {config_file:?}");
+    // -- Generate the complete registry URL from the given host[:path]
+    let registry_url: Url = make_registry_url(&args.registry)?;
 
-    let config = Config::try_from(config_file.as_ref())?;
     match args.command {
-        Commands::Catalog => commands::catalog_handler(&config).await?,
-        Commands::Tags { name } => commands::tags_handler(&config, &name).await?,
+        Commands::Catalog => commands::catalog_handler(&registry_url).await?,
+        Commands::Tags { name } => commands::tags_handler(&registry_url, &name).await?,
         Commands::Show { image, tag } => {
-            commands::show_handler(&config, &image, &tag.unwrap_or("latest".to_string())).await?;
+            commands::show_handler(&registry_url, &image, &tag.unwrap_or("latest".to_string()))
+                .await?;
         }
-        Commands::Delete { image, tag } => commands::delete_handler(&config, &image, &tag).await?,
-        Commands::Check => commands::check_handler(&config).await?,
+        Commands::Delete { image, tag } => {
+            commands::delete_handler(&registry_url, &image, &tag).await?;
+        }
+        Commands::Check => commands::check_handler(&registry_url).await?,
     }
 
     Ok(())