[pve-devel] [PATCH proxmox-perl-rs v4 4/5] pve-rs: sdn: fabrics: add helper to generate ifupdown2 configuration

[Gabriel Goller]

From: Stefan Hanreich <s.hanreich at proxmox.com>

SDN fabrics can be used to configure IP addresses on interfaces
directly, so we need to generate the respective ifupdown2
configuration from the fabrics configuration. We also set some
additional properties that are required for interfaces that are part
of a fabric (IP forwarding). We use dummy interfaces, instead of
loopback interfaces, for configuring the router IP of the node, so for
each fabric we generate a dummy interface that carries the IP.

Currently this is a simple implementation that builds a String from
the SDN fabrics configuration, but in the future we intend to create a
full-fledged crate for reading / writing ifupdown2 configuration
files.

Co-authored-by: Gabriel Goller <g.goller at proxmox.com>
Signed-off-by: Stefan Hanreich <s.hanreich at proxmox.com>
---
 pve-rs/Cargo.toml                  |   2 +
 pve-rs/src/bindings/sdn/fabrics.rs | 104 +++++++++++++++++++++++++++++
 2 files changed, 106 insertions(+)

diff --git a/pve-rs/Cargo.toml b/pve-rs/Cargo.toml
index 19c7431206e9..6917ae511927 100644
--- a/pve-rs/Cargo.toml
+++ b/pve-rs/Cargo.toml
@@ -33,9 +33,11 @@ proxmox-apt = { version = "0.99", features = ["cache"] }
 proxmox-apt-api-types = "2"
 proxmox-base64 = "1"
 proxmox-config-digest = "1"
+proxmox-frr = { version = "0.1" }
 proxmox-http = { version = "1", features = ["client-sync", "client-trait"] }
 proxmox-http-error = "1"
 proxmox-log = "1"
+proxmox-network-types = "0.1"
 proxmox-notify = { version = "1", features = ["pve-context"] }
 proxmox-openid = "1"
 proxmox-resource-scheduling = "1"
diff --git a/pve-rs/src/bindings/sdn/fabrics.rs b/pve-rs/src/bindings/sdn/fabrics.rs
index a7a740f5aac9..099c1a7ab515 100644
--- a/pve-rs/src/bindings/sdn/fabrics.rs
+++ b/pve-rs/src/bindings/sdn/fabrics.rs
@@ -6,6 +6,8 @@ pub mod pve_rs_sdn_fabrics {
     //! / writing the configuration, as well as for generating ifupdown2 and FRR configuration.
 
     use std::collections::{BTreeMap, HashSet};
+    use std::fmt::Write;
+    use std::net::IpAddr;
     use std::ops::Deref;
     use std::sync::Mutex;
 
@@ -15,6 +17,7 @@ pub mod pve_rs_sdn_fabrics {
 
     use perlmod::Value;
     use proxmox_frr::serializer::to_raw_config;
+    use proxmox_network_types::ip_address::Cidr;
     use proxmox_section_config::typed::SectionConfigData;
     use proxmox_ve_config::common::valid::Validatable;
 
@@ -349,4 +352,105 @@ pub mod pve_rs_sdn_fabrics {
 
         to_raw_config(&frr_config)
     }
+
+    /// Helper method to generate the default /e/n/i config for a given CIDR.
+    fn render_interface(name: &str, cidr: Cidr, is_dummy: bool) -> Result<String, Error> {
+        let mut interface = String::new();
+
+        writeln!(interface)?;
+        writeln!(interface, "auto {name}")?;
+        match cidr {
+            Cidr::Ipv4(_) => writeln!(interface, "iface {name} inet static")?,
+            Cidr::Ipv6(_) => writeln!(interface, "iface {name} inet6 static")?,
+        }
+        writeln!(interface, "\taddress {cidr}")?;
+        if is_dummy {
+            writeln!(interface, "\tlink-type dummy")?;
+        }
+        writeln!(interface, "\tip-forward 1")?;
+
+        Ok(interface)
+    }
+
+    /// Class method: Generate the ifupdown2 configuration for a given node.
+    #[export]
+    fn get_interfaces_etc_network_config(
+        #[try_from_ref] this: &PerlFabricConfig,
+        node_id: NodeId,
+    ) -> Result<String, Error> {
+        let config = this.fabric_config.lock().unwrap();
+        let mut interfaces = String::new();
+
+        let node_fabrics = config.values().filter_map(|entry| {
+            entry
+                .get_node(&node_id)
+                .map(|node| (entry.fabric(), node))
+                .ok()
+        });
+
+        for (fabric, node) in node_fabrics {
+            // dummy interface
+            if let Some(ip) = node.ip() {
+                let interface = render_interface(
+                    &format!("dummy_{}", fabric.id()),
+                    Cidr::new_v4(ip, 32)?,
+                    true,
+                )?;
+                write!(interfaces, "{interface}")?;
+            }
+            if let Some(ip6) = node.ip6() {
+                let interface = render_interface(
+                    &format!("dummy_{}", fabric.id()),
+                    Cidr::new_v6(ip6, 128)?,
+                    true,
+                )?;
+                write!(interfaces, "{interface}")?;
+            }
+            match node {
+                ConfigNode::Openfabric(node_section) => {
+                    for interface in node_section.properties().interfaces() {
+                        if let Some(ip) = interface.ip() {
+                            let interface =
+                                render_interface(interface.name(), Cidr::from(ip), false)?;
+                            write!(interfaces, "{interface}")?;
+                        }
+                        if let Some(ip) = interface.ip6() {
+                            let interface =
+                                render_interface(interface.name(), Cidr::from(ip), false)?;
+                            write!(interfaces, "{interface}")?;
+                        }
+
+                        // If not ip is configured, add auto and empty iface to bring interface up
+                        if let (None, None) = (interface.ip(), interface.ip6()) {
+                            writeln!(interfaces)?;
+                            writeln!(interfaces, "auto {}", interface.name())?;
+                            writeln!(interfaces, "iface {}", interface.name())?;
+                            writeln!(interfaces, "\tip-forward 1")?;
+                        }
+                    }
+                }
+                ConfigNode::Ospf(node_section) => {
+                    for interface in node_section.properties().interfaces() {
+                        if let Some(ip) = interface.ip() {
+                            let interface =
+                                render_interface(interface.name(), Cidr::from(ip), false)?;
+                            write!(interfaces, "{interface}")?;
+                        } else {
+                            let interface = render_interface(
+                                interface.name(),
+                                Cidr::from(IpAddr::from(
+                                    node.ip()
+                                        .ok_or(anyhow::anyhow!("there has to be a ipv4 address"))?,
+                                )),
+                                false,
+                            )?;
+                            write!(interfaces, "{interface}")?;
+                        }
+                    }
+                }
+            }
+        }
+
+        Ok(interfaces)
+    }
 }
-- 
2.39.5