api/api-types: refactor api endpoint version, add api types

Add a dedicated api type for the `version` api endpoint and helper
methods for supported feature comparison.
This will be used to detect api incompatibility of older hosts, not
supporting some features.

Use the new api type to refactor the version endpoint and set it as
return type.

Signed-off-by: Christian Ebner <c.ebner@proxmox.com>

pbs-api-types/src/lib.rs

@@ -155,6 +155,9 @@ pub use zfs::*;
 mod metrics;
 pub use metrics::*;
 
+mod version;
+pub use version::*;
+
 const_regex! {
     // just a rough check - dummy acceptor is used before persisting
     pub OPENSSL_CIPHERS_REGEX = r"^[0-9A-Za-z_:, +!\-@=.]+$";

pbs-api-types/src/version.rs

@@ -0,0 +1,88 @@
+//! Defines the types for the api version info endpoint
+use std::convert::TryFrom;
+
+use anyhow::{format_err, Context};
+
+use proxmox_schema::api;
+
+#[api(
+    description: "Api version information",
+    properties: {
+        "version": {
+            description: "Version 'major.minor'",
+            type: String,
+        },
+        "release": {
+            description: "Version release",
+            type: String,
+        },
+        "repoid": {
+            description: "Version repository id",
+            type: String,
+        },
+        "features": {
+            description: "List of supported features",
+            type: Array,
+            items: {
+                type: String,
+                description: "Feature id",
+            },
+        },
+    }
+)]
+#[derive(serde::Deserialize, serde::Serialize)]
+pub struct ApiVersionInfo {
+    pub version: String,
+    pub release: String,
+    pub repoid: String,
+    #[serde(default, skip_serializing_if = "Vec::is_empty")]
+    pub features: Vec<String>,
+}
+
+pub type ApiVersionMajor = u64;
+pub type ApiVersionMinor = u64;
+pub type ApiVersionRelease = u64;
+
+pub struct ApiVersion {
+    pub major: ApiVersionMajor,
+    pub minor: ApiVersionMinor,
+    pub release: ApiVersionRelease,
+    pub repoid: String,
+    pub features: Vec<String>,
+}
+
+impl TryFrom<ApiVersionInfo> for ApiVersion {
+    type Error = anyhow::Error;
+
+    fn try_from(value: ApiVersionInfo) -> Result<Self, Self::Error> {
+        let (major, minor) = value
+            .version
+            .split_once('.')
+            .ok_or_else(|| format_err!("malformed API version {}", value.version))?;
+
+        let major: ApiVersionMajor = major
+            .parse()
+            .with_context(|| "failed to parse major version")?;
+        let minor: ApiVersionMinor = minor
+            .parse()
+            .with_context(|| "failed to parse minor version")?;
+        let release: ApiVersionRelease = value
+            .release
+            .parse()
+            .with_context(|| "failed to parse release version")?;
+
+        Ok(Self {
+            major,
+            minor,
+            release,
+            repoid: value.repoid.clone(),
+            features: value.features.clone(),
+        })
+    }
+}
+
+impl ApiVersion {
+    pub fn supports_feature(&self, feature: &str) -> bool {
+        self.features.iter().any(|f| f == feature)
+    }
+}

src/api2/version.rs

@@ -1,27 +1,35 @@
 //! Version information
 
 use anyhow::Error;
-use serde_json::{json, Value};
+use serde_json::Value;
 
-use proxmox_router::{ApiHandler, ApiMethod, Permission, Router, RpcEnvironment};
-use proxmox_schema::ObjectSchema;
+use proxmox_router::{ApiMethod, Permission, Router, RpcEnvironment};
+use proxmox_schema::api;
 
-fn get_version(
+use pbs_api_types::ApiVersionInfo;
+
+const FEATURES: &'static [&'static str] = &[];
+
+#[api(
+    returns: {
+        type: ApiVersionInfo,
+    },
+    access: {
+        permission: &Permission::Anybody,
+    }
+)]
+///Proxmox Backup Server API version.
+fn version(
     _param: Value,
     _info: &ApiMethod,
     _rpcenv: &mut dyn RpcEnvironment,
-) -> Result<Value, Error> {
-    Ok(json!({
-        "version": pbs_buildcfg::PROXMOX_PKG_VERSION,
-        "release": pbs_buildcfg::PROXMOX_PKG_RELEASE,
-        "repoid": pbs_buildcfg::PROXMOX_PKG_REPOID
-    }))
+) -> Result<ApiVersionInfo, Error> {
+    Ok(ApiVersionInfo {
+        version: pbs_buildcfg::PROXMOX_PKG_VERSION.to_string(),
+        release: pbs_buildcfg::PROXMOX_PKG_RELEASE.to_string(),
+        repoid: pbs_buildcfg::PROXMOX_PKG_REPOID.to_string(),
+        features: FEATURES.iter().map(|feature| feature.to_string()).collect(),
+    })
 }
 
-pub const ROUTER: Router = Router::new().get(
-    &ApiMethod::new(
-        &ApiHandler::Sync(&get_version),
-        &ObjectSchema::new("Proxmox Backup Server API version.", &[]),
-    )
-    .access(None, &Permission::Anybody),
-);
+pub const ROUTER: Router = Router::new().get(&API_METHOD_VERSION);