feature: validate presets before starting a server

src/lib/config.rs

@@ -52,6 +52,14 @@ pub enum ProgramStartError {
     ConfigCliError(ConfigError),
     InvalidArgs(Error),
     FromFile(FromFileError),
+    PresetOptions {
+        name: String,
+        error: String
+    },
+    PresetNotSupported {
+        name: String,
+    },
+    Presets(Vec<ProgramStartError>),
     Ip,
     BindHttp(std::io::Error),
     BindHttps(std::io::Error),
@@ -93,6 +101,24 @@ impl std::fmt::Display for ProgramStartError {
             ProgramStartError::Ip => {
                 write!(f, "could not retrieve the address for the config-server")
             }
+            ProgramStartError::PresetOptions {
+                name,
+                error
+            } => {
+                write!(f, "preset {} could not be parsed\nerror: {}", name, error)
+            }
+            ProgramStartError::PresetNotSupported {
+                name,
+            } => {
+                write!(f, "preset {} is not currently supported", name)
+            }
+            ProgramStartError::Presets(errors) => {
+                let res = errors.iter()
+                    .map(|x| x.to_string())
+                    .collect::<Vec<String>>()
+                    .join("\n");
+                write!(f, "{}", res)
+            }
         }
     }
 }

src/lib/setup.rs

@@ -13,6 +13,7 @@ use serde_json;
 use std::collections::HashMap;
 use std::sync::Arc;
 use std::sync::Mutex;
+use config::ProgramStartError;
 
 pub type PresetsMap = HashMap<usize, Box<Preset<AppState>>>;
 
@@ -36,6 +37,41 @@ pub fn apply_presets(
     app.default_resource(|r| r.f(proxy_transform))
 }
 
+pub fn validate_presets(presets: Vec<&str>, program_config: &ProgramConfig) -> Result<(), ProgramStartError> {
+    let mut errors = vec![];
+    program_config.presets.iter().enumerate().for_each(|(i, preset)| {
+        match preset.name.as_str() {
+            "m2" => {
+                let preset_opts: Result<M2PresetOptions, serde_json::Error>
+                    = serde_json::from_value(preset.options.clone());
+
+                match preset_opts {
+                    Err(e) => {
+                        errors.push(ProgramStartError::PresetOptions {
+                            error: e.to_string(),
+                            name: "m2".to_string()
+                        })
+                    },
+                    _ => {}
+                }
+            }
+            _ => {
+                errors.push(
+                    ProgramStartError::PresetNotSupported {
+                        name: "m2".to_string()
+                    }
+                );
+            },
+        }
+    });
+
+    if errors.len() > 0 {
+        Err(ProgramStartError::Presets(errors))
+    } else {
+        Ok(())
+    }
+}
+
 pub fn state_and_presets(
     opts: &ProgramOptions,
     program_config: &ProgramConfig,

src/lib/system.rs

@@ -9,6 +9,7 @@ use setup::state_and_presets;
 use ssl;
 use std::net::SocketAddr;
 use std::net::SocketAddrV4;
+use setup::validate_presets;
 
 pub fn create(opts: ProgramOptions) -> Result<(actix::SystemRunner, String), ProgramStartError> {
     //
@@ -41,6 +42,11 @@ pub fn create(opts: ProgramOptions) -> Result<(actix::SystemRunner, String), Pro
     //
     let maybe_seed = server_opts.seed_file.clone();
 
+    //
+    // Exit early if any presets fail validation
+    //
+    let _validated_presets = validate_presets(vec!["m2"], &program_config)?;
+
     //
     // Now start the server
     //