adding payments for VM contracts

final_tables.surql

@@ -1,91 +0,0 @@
-DEFINE TABLE account SCHEMAFULL;
-DEFINE FIELD balance ON TABLE account TYPE int;
-DEFINE FIELD tmp_locked ON TABLE account TYPE int;
-DEFINE FIELD escrow ON TABLE account TYPE int;
-DEFINE FIELD email ON TABLE account TYPE string;
-DEFINE FIELD hratls_pubkey ON TABLE account TYPE string;
-DEFINE FIELD vm_nodes ON TABLE account TYPE array<record>;
-DEFINE FIELD app_nodes ON TABLE account TYPE array<record>;
-
-DEFINE TABLE package SCHEMAFULL;
-DEFINE FIELD url ON TABLE package TYPE array<string>;
-
-DEFINE TABLE kernel SCHEMAFULL;
-DEFINE FIELD url ON TABLE kernel TYPE array<string>;
-
-DEFINE TABLE dtrfs SCHEMAFULL;
-DEFINE FIELD url ON TABLE dtrfs TYPE array<string>;
-DEFINE FIELD kernel ON TABLE dtrfs TYPE record<kernel>;
-
-DEFINE TABLE vm_node SCHEMAFULL;
-DEFINE FIELD country ON TABLE vm_node TYPE string;
-DEFINE FIELD region ON TABLE vm_node TYPE string;
-DEFINE FIELD city ON TABLE vm_node TYPE string;
-DEFINE FIELD ip ON TABLE vm_node TYPE string;
-DEFINE FIELD avail_mem_mb ON TABLE vm_node TYPE int;
-DEFINE FIELD avail_vcpus ON TABLE vm_node TYPE int;
-DEFINE FIELD avail_storage_gbs ON TABLE vm_node TYPE int;
-DEFINE FIELD avail_ipv4 ON TABLE vm_node TYPE int;
-DEFINE FIELD avail_ipv6 ON TABLE vm_node TYPE int;
-DEFINE FIELD avail_ports ON TABLE vm_node TYPE int;
-DEFINE FIELD max_ports_per_vm ON TABLE vm_node TYPE int;
-DEFINE FIELD price ON TABLE vm_node TYPE int;
-DEFINE FIELD offline_minutes ON TABLE vm_node TYPE int;
-
-DEFINE TABLE vm_contract TYPE RELATION FROM account TO vm_node SCHEMAFULL;
-DEFINE FIELD state ON TABLE vm_contract TYPE string;
-DEFINE FIELD hostname ON TABLE vm_contract TYPE string;
-DEFINE FIELD mapped_ports ON TABLE vm_contract TYPE array<[int, int]>;
-DEFINE FIELD public_ipv4 ON TABLE vm_contract TYPE string;
-DEFINE FIELD public_ipv6 ON TABLE vm_contract TYPE string;
-DEFINE FIELD disk_size_gb ON TABLE vm_contract TYPE int;
-DEFINE FIELD vcpus ON TABLE vm_contract TYPE int;
-DEFINE FIELD memory_mb ON TABLE vm_contract TYPE int;
-DEFINE FIELD dtrfs ON TABLE vm_contract TYPE record<dtrfs>;
-DEFINE FIELD created_at ON TABLE vm_contract TYPE datetime;
-DEFINE FIELD updated_at ON TABLE vm_contract TYPE datetime;
-DEFINE FIELD price_per_unit ON TABLE vm_contract TYPE int;
-DEFINE FIELD locked_nano ON TABLE vm_contract TYPE int;
-DEFINE FIELD collected_at ON TABLE vm_contract TYPE datetime;
-
-DEFINE TABLE app_node SCHEMAFULL;
-DEFINE FIELD country ON TABLE app_node TYPE string;
-DEFINE FIELD region ON TABLE app_node TYPE string;
-DEFINE FIELD city ON TABLE app_node TYPE string;
-DEFINE FIELD ip ON TABLE app_node TYPE string;
-DEFINE FIELD avail_mem_mb ON TABLE app_node TYPE int;
-DEFINE FIELD avail_vcpus ON TABLE app_node TYPE int;
-DEFINE FIELD avail_storage_gbs ON TABLE app_node TYPE int;
-DEFINE FIELD avail_ports ON TABLE app_node TYPE int;
-DEFINE FIELD max_ports_per_app ON TABLE app_node TYPE int;
-DEFINE FIELD price ON TABLE app_node TYPE int;
-DEFINE FIELD offline_minutes ON TABLE app_node TYPE int;
-
-DEFINE TABLE app_contract TYPE RELATION FROM account TO app_node SCHEMAFULL;
-DEFINE FIELD state ON TABLE app_contract TYPE string;
-DEFINE FIELD app_name ON TABLE app_contract TYPE string;
-DEFINE FIELD mapped_ports ON TABLE app_contract TYPE array<[int, int]>;
-DEFINE FIELD host_ipv4 ON TABLE app_contract TYPE string;
-DEFINE FIELD vcpus ON TABLE app_contract TYPE int;
-DEFINE FIELD memory_mb ON TABLE app_contract TYPE int;
-DEFINE FIELD disk_size_gb ON TABLE app_contract TYPE int;
-DEFINE FIELD created_at ON TABLE app_contract TYPE datetime;
-DEFINE FIELD updated_at ON TABLE app_contract TYPE datetime;
-DEFINE FIELD price_per_unit ON TABLE app_contract TYPE int;
-DEFINE FIELD locked_nano ON TABLE app_contract TYPE int;
-DEFINE FIELD collected_at ON TABLE app_contract TYPE datetime;
-DEFINE FIELD mr_enclave ON TABLE app_contract TYPE record<package>;
-
-DEFINE TABLE ban TYPE RELATION FROM account TO account;
-DEFINE FIELD created_at ON TABLE ban TYPE datetime;
-
-DEFINE TABLE kick TYPE RELATION FROM account TO account;
-DEFINE FIELD created_at ON TABLE kick TYPE datetime;
-DEFINE FIELD reason ON TABLE kick TYPE string;
-DEFINE FIELD contract ON TABLE kick TYPE record<vm_contract|app_contract>;
-
-DEFINE TABLE report TYPE RELATION FROM account TO vm_node|app_node;
-DEFINE FIELD created_at ON TABLE ban TYPE datetime;
-DEFINE FIELD reason ON TABLE ban TYPE string;
-
-DEFINE TABLE operator TYPE RELATION FROM account TO vm_node|app_node;

scripts/deploy.sh

@@ -17,5 +17,10 @@ ssh $server systemctl stop detee-brain.service
 scp target/release/brain $server:/usr/local/bin/detee-brain
 ssh $server mkdir -p /etc/detee/brain/
 scp scripts/detee-brain.service $server:/etc/systemd/system/detee-brain.service
+scp surql/detee-brain-contracts.service $server:/etc/systemd/system/detee-brain-contracts.service
+scp surql/detee-brain-contracts.timer $server:/etc/systemd/system/detee-brain-contracts.timer
+scp surql/brain-timer.sh $server:/etc/detee/brain/brain-timer.sh
+scp surql/timer.sql $server:/etc/detee/brain/timer.surql
 ssh $server systemctl daemon-reload
 ssh $server systemctl start detee-brain.service
+ssh $server systemctl enable --now detee-brain-contracts.timer

src/db/general.rs

@@ -192,8 +192,8 @@ impl Operator {
     pub async fn inspect(db: &Surreal<Client>, account: &str) -> Result<Option<Self>, Error> {
         let mut result = db
             .query(format!(
-                "$vm_nodes = (select id from vm_node where operator = account:{account}).id;
+                "LET $vm_nodes = (select id from vm_node where operator = account:{account}).id;
-                $app_nodes = (select id from app_node where operator = account:{account}).id;
+                LET $app_nodes = (select id from app_node where operator = account:{account}).id;
                 select *,
                     id as account,
                     email,

src/db/vm.rs

@@ -30,7 +30,27 @@ pub struct VmNode {
     pub avail_ports: u32,
     pub max_ports_per_vm: u32,
     pub price: u64,
-    pub offline_minutes: u64,
+    pub connected_at: Datetime,
+    pub disconnected_at: Datetime,
+}
+
+impl VmNode {
+    pub async fn register(self, db: &Surreal<Client>) -> Result<(), Error> {
+        Account::get_or_create(db, &self.operator.key().to_string()).await?;
+        let _: Option<VmNode> = db.upsert(self.id.clone()).content(self).await?;
+        Ok(())
+    }
+
+    pub async fn set_online(db: &Surreal<Client>, vm_node_id: &str) -> Result<(), Error> {
+        db.query(format!("UPDATE {VM_NODE}:{vm_node_id} SET connected_at = time::now();")).await?;
+        Ok(())
+    }
+
+    pub async fn set_offline(db: &Surreal<Client>, vm_node_id: &str) -> Result<(), Error> {
+        db.query(format!("UPDATE {VM_NODE}:{vm_node_id} SET disconnected_at = time::now();"))
+            .await?;
+        Ok(())
+    }
 }
 
 #[derive(Serialize)]
@@ -51,14 +71,6 @@ impl VmNodeResources {
     }
 }
 
-impl VmNode {
-    pub async fn register(self, db: &Surreal<Client>) -> Result<(), Error> {
-        Account::get_or_create(db, &self.operator.key().to_string()).await?;
-        let _: Option<VmNode> = db.upsert(self.id.clone()).content(self).await?;
-        Ok(())
-    }
-}
-
 #[derive(Debug, Serialize, Deserialize)]
 pub struct VmNodeWithReports {
     pub id: RecordId,
@@ -75,13 +87,10 @@ pub struct VmNodeWithReports {
     pub avail_ports: u32,
     pub max_ports_per_vm: u32,
     pub price: u64,
-    pub offline_minutes: u64,
     pub reports: Vec<Report>,
 }
 
 impl VmNodeWithReports {
-    // TODO: find a more elegant way to do this than importing gRPC in the DB module
-    // https://en.wikipedia.org/wiki/Dependency_inversion_principle
     pub async fn find_by_filters(
         db: &Surreal<Client>,
         filters: vm_proto::VmNodeFilters,
@@ -115,7 +124,7 @@ impl VmNodeWithReports {
         if !filters.ip.is_empty() {
             query += &format!("&& ip = '{}' ", filters.ip);
         }
-        query += ";";
+        query += " && connected_at > disconnected_at;";
         let mut result = db.query(query).await?;
         let vm_nodes: Vec<Self> = result.take(0)?;
         Ok(vm_nodes)
@@ -191,7 +200,46 @@ impl NewVmReq {
     }
 
     pub async fn submit(self, db: &Surreal<Client>) -> Result<(), Error> {
-        let _: Vec<Self> = db.insert(NEW_VM_REQ).relation(self).await?;
+        let locked_nano = self.locked_nano;
+        let account = self.admin.key().to_string();
+        let vm_id = self.id.key().to_string();
+        let vm_node = self.vm_node.key().to_string();
+        // TODO: check for possible injection and maybe use .bind()
+        let query = format!(
+            "
+            BEGIN TRANSACTION;
+            UPDATE account:{account} SET balance -= {locked_nano};
+            IF account:{account}.balance < 0 {{
+                THROW 'Insufficient funds.'
+            }};
+            UPDATE account:{account} SET tmp_locked += {locked_nano};
+            RELATE
+                account:{account}
+                ->new_vm_req:{vm_id}
+                ->vm_node:{vm_node}
+            CONTENT {{
+                created_at: time::now(), hostname: '{}', vcpus: {}, memory_mb: {}, disk_size_gb: {},
+                extra_ports: {}, public_ipv4: {:?}, public_ipv6: {:?},
+                dtrfs_url: '{}', dtrfs_sha: '{}', kernel_url: '{}', kernel_sha: '{}',
+                price_per_unit: {}, locked_nano: {locked_nano}, error: ''
+            }};
+            COMMIT TRANSACTION;
+        ",
+            self.hostname,
+            self.vcpus,
+            self.memory_mb,
+            self.disk_size_gb,
+            format!("{:?}", self.extra_ports,),
+            self.public_ipv4,
+            self.public_ipv6,
+            self.dtrfs_url,
+            self.dtrfs_sha,
+            self.kernel_url,
+            self.kernel_sha,
+            self.price_per_unit
+        );
+        //let _: Vec<Self> = db.insert(NEW_VM_REQ).relation(self).await?;
+        db.query(query).await?;
         Ok(())
     }
 }
@@ -366,9 +414,12 @@ impl ActiveVm {
             collected_at: new_vm_req.created_at,
         };
 
+        let admin_account = active_vm.admin.key().to_string();
+        let locked_nano = active_vm.locked_nano;
         let _: Vec<ActiveVm> = db.insert(()).relation(active_vm).await?;
-
         NewVmReq::delete(db, id).await?;
+        db.query(format!("UPDATE {ACCOUNT}:{admin_account} SET tmp_locked -= {locked_nano};"))
+            .await?;
         Ok(())
     }
 
@@ -750,7 +801,8 @@ impl From<&old_brain::BrainData> for Vec<VmNode> {
                 avail_ports: old_node.avail_ports,
                 max_ports_per_vm: old_node.max_ports_per_vm,
                 price: old_node.price,
-                offline_minutes: old_node.offline_minutes,
+                disconnected_at: Datetime::default(),
+                connected_at: Datetime::default(),
             });
         }
         nodes

src/grpc/vm.rs

@@ -53,7 +53,8 @@ impl BrainVmDaemon for VmDaemonServer {
             avail_ipv6: 0,
             avail_ports: 0,
             max_ports_per_vm: 0,
-            offline_minutes: 0,
+            disconnected_at: surrealdb::sql::Datetime::default(),
+            connected_at: surrealdb::sql::Datetime::default(),
         }
         .register(&self.db)
         .await?;
@@ -83,6 +84,7 @@ impl BrainVmDaemon for VmDaemonServer {
             &auth.signature,
         )?;
         info!("Daemon {} connected to receive brain messages", pubkey);
+        let _ = db::VmNode::set_online(&self.db, &pubkey).await;
 
         let (tx, rx) = mpsc::channel(6);
         {
@@ -194,7 +196,8 @@ impl BrainVmDaemon for VmDaemonServer {
                     _ => {}
                 },
                 Err(e) => {
-                    log::warn!("Daemon disconnected: {e:?}");
+                    log::warn!("Daemon disconnected for {pubkey}: {e:?}");
+                    let _ = db::VmNode::set_offline(&self.db, &pubkey).await;
                 }
             }
         }

surql/README.md

@@ -0,0 +1,2 @@
+This is actually SurrealQL (`.surql`), but the files have the `.sql`
+extension to enable syntax coloring.

surql/brain-timer.sh

@@ -0,0 +1,12 @@
+#!/bin/bash
+
+source /etc/detee/brain/config.ini
+
+import="docker run -i --rm --net=host \
+  --volume "/etc/detee/brain/timer.surql:/timer.surql" \
+  surrealdb/surrealdb:latest import \
+  --endpoint "http://${DB_URL}" \
+  --username $DB_USER --password "$DB_PASS" \
+  --namespace $DB_NAMESPACE --database $DB_NAME"
+
+$import timer.surql

surql/detee-brain-contracts.service

@@ -0,0 +1,6 @@
+[Unit]
+Description=Process brain contracts
+
+[Service]
+Type=oneshot
+ExecStart=/etc/detee/brain/brain-timer.sh

surql/detee-brain-contracts.timer

@@ -0,0 +1,9 @@
+[Unit]
+Description=Run detee-brain-contracts.service every minute
+
+[Timer]
+OnCalendar=*-*-* *:*:00
+Persistent=true
+
+[Install]
+WantedBy=timers.target

surql/functions.sql

@@ -0,0 +1,30 @@
+DEFINE FUNCTION OVERWRITE fn::vm_price_per_minute(
+	$vm_id: record
+) {
+    LET $vm = (select * from $vm_id)[0];
+    LET $ip_price = 0;
+    IF $vm.public_ipv4.len() > 0 {
+        $ip_price = 10
+    };
+    RETURN (
+      ($vm.vcpus * 10) + (($vm.memory_mb + 256) / 200) + ($vm.disk_size_gb / 10) + $ip_price)
+    * $vm.price_per_unit;
+};
+
+DEFINE FUNCTION OVERWRITE fn::delete_vm(
+	$vm_id: record
+) {
+    LET $vm = (select * from $vm_id)[0];
+    LET $account = $vm.in;
+    LET $deleted_vm = $vm.patch([{
+		'op': 'replace',
+		'path': 'id',
+		'value': type::record("deleted_vm:" + record::id($vm.id))
+    }]);
+    IF $vm.locked_nano >= 0 {
+        UPDATE $account SET balance += $vm.locked_nano;
+    };
+    INSERT RELATION INTO deleted_vm ( $deleted_vm );
+    DELETE $vm.id;
+};
+

surql/tables.sql

@@ -18,7 +18,8 @@ DEFINE FIELD avail_ipv6 ON TABLE vm_node TYPE int;
 DEFINE FIELD avail_ports ON TABLE vm_node TYPE int;
 DEFINE FIELD max_ports_per_vm ON TABLE vm_node TYPE int;
 DEFINE FIELD price ON TABLE vm_node TYPE int;
-DEFINE FIELD offline_minutes ON TABLE vm_node TYPE int;
+DEFINE FIELD connected_at ON TABLE vm_node TYPE datetime;
+DEFINE FIELD disconnected_at ON TABLE vm_node TYPE datetime;
 
 DEFINE TABLE new_vm_req TYPE RELATION FROM account TO vm_node SCHEMAFULL;
 DEFINE FIELD hostname ON TABLE new_vm_req TYPE string;
@@ -74,7 +75,7 @@ DEFINE FIELD memory_mb ON TABLE deleted_vm TYPE int;
 DEFINE FIELD dtrfs_sha ON TABLE deleted_vm TYPE string;
 DEFINE FIELD kernel_sha ON TABLE deleted_vm TYPE string;
 DEFINE FIELD created_at ON TABLE deleted_vm TYPE datetime;
-DEFINE FIELD deleted_at ON TABLE deleted_vm TYPE datetime;
+DEFINE FIELD deleted_at ON TABLE deleted_vm TYPE datetime DEFAULT time::now();
 DEFINE FIELD price_per_unit ON TABLE deleted_vm TYPE int;
 
 DEFINE TABLE app_node SCHEMAFULL;

surql/testing/data.sql

@@ -0,0 +1,114 @@
+INSERT {
+	id: vm_node:online_node,
+	avail_ipv4: 0,
+	avail_ipv6: 0,
+	avail_mem_mb: 25000,
+	avail_ports: 19999,
+	avail_storage_gbs: 700,
+	avail_vcpus: 27,
+	city: 'Pula',
+	connected_at: time::now(),
+	country: 'HR',
+	disconnected_at: time::now() - 1m,
+	ip: '184.107.169.199',
+	max_ports_per_vm: 5,
+	operator: account:operator1,
+	price: 18000,
+	region: 'Istria'
+};
+
+INSERT {
+	id: vm_node:offline_node,
+	avail_ipv4: 0,
+	avail_ipv6: 0,
+	avail_mem_mb: 25000,
+	avail_ports: 19999,
+	avail_storage_gbs: 700,
+	avail_vcpus: 27,
+	city: 'Pula',
+	connected_at: time::now() - 1m,
+	country: 'HR',
+	disconnected_at: time::now(),
+	ip: '184.107.200.100',
+	max_ports_per_vm: 5,
+	operator: account:operator2,
+	price: 18000,
+	region: 'Istria'
+};
+
+INSERT {
+ 	balance: 10000000000,
+	email: '',
+	escrow: 0,
+	id: account:user1,
+	tmp_locked: 0
+};
+
+
+INSERT {
+ 	balance: 10000000000,
+	email: '',
+	escrow: 0,
+	id: account:user2,
+	tmp_locked: 0
+};
+
+INSERT {
+ 	balance: 10000000000,
+	email: '',
+	escrow: 5000000000000,
+	id: account:operator1,
+	tmp_locked: 0
+};
+
+INSERT {
+ 	balance: 10000000000,
+	email: '',
+	escrow: 5000000000000,
+	id: account:operator2,
+	tmp_locked: 0
+};
+
+INSERT RELATION {
+	id: active_vm:vm1,
+	in: account:user1,
+	out: vm_node:online_node,
+	collected_at: time::now(),
+	created_at: time::now(),
+	disk_size_gb: 400,
+	dtrfs_sha: 'd207644ee60d54009b6ecdfb720e2ec251cde31774dd249fcc7435aca0377990',
+	hostname: 'vm1',
+	kernel_sha: 'e765e56166ef321b53399b9638584d1279821dbe3d46191c1f66bbaa075e7919',
+	locked_nano: 4000,
+	mapped_ports: [],
+	memory_mb: 80000,
+	price_per_unit: 20000,
+	public_ipv4: '192.168.10.10',
+	public_ipv6: '',
+	vcpus: 40
+};
+
+INSERT RELATION {
+	id: active_vm:vm2,
+	in: account:user2,
+	out: vm_node:offline_node,
+	collected_at: time::now(),
+	created_at: time::now(),
+	disk_size_gb: 10,
+	dtrfs_sha: 'd207644ee60d54009b6ecdfb720e2ec251cde31774dd249fcc7435aca0377990',
+	hostname: 'vm1',
+	kernel_sha: 'e765e56166ef321b53399b9638584d1279821dbe3d46191c1f66bbaa075e7919',
+	locked_nano: 80000000,
+	mapped_ports: [
+		[
+			44551,
+			22
+		]
+	],
+	memory_mb: 5000,
+	price_per_unit: 20000,
+	public_ipv4: '',
+	public_ipv6: '',
+	vcpus: 4
+};
+

surql/testing/run_test1.sh

@@ -0,0 +1,42 @@
+#!/bin/bash
+cd -- "$( dirname -- "${BASH_SOURCE[0]}" )"
+import="docker run -i --rm --net=host \
+  --volume "$(pwd)/../:/opt/scripts/" \
+  surrealdb/surrealdb:latest import \
+  --endpoint http://127.0.0.1:8000 \
+  --username root --password root \
+  --namespace testing --database testbrain"
+
+sql="docker run -i --rm --net=host \
+  surrealdb/surrealdb:latest sql \
+  --hide-welcome \
+  --endpoint http://127.0.0.1:8000 \
+  --username root --password root \
+  --namespace testing --database testbrain"
+
+echo DELETING EXISTING DATA:
+echo "REMOVE DATABASE testbrain;" | $sql
+
+echo CREATING TABLES:
+$import /opt/scripts/tables.sql
+
+echo LOADING FUNCTIONS:
+$import /opt/scripts/functions.sql
+
+echo LOADING MOCK DATA:
+$import /opt/scripts/testing/data.sql
+
+echo RUNNING CRON for 10 minutes:
+$import /opt/scripts/timer.sql
+$import /opt/scripts/timer.sql
+$import /opt/scripts/timer.sql
+$import /opt/scripts/timer.sql
+$import /opt/scripts/timer.sql
+$import /opt/scripts/timer.sql
+$import /opt/scripts/timer.sql
+$import /opt/scripts/timer.sql
+$import /opt/scripts/timer.sql
+$import /opt/scripts/timer.sql
+
+echo CHECK IF DATA GOT MODIFIED CORRECTLY:
+$import /opt/scripts/testing/verification.sql

surql/testing/verification.sql

@@ -0,0 +1,13 @@
+if (select balance from account:operator1)[0].balance != 10000020000 {
+    throw("Operator 1 did't get paid for serving a VM.")
+};
+if (select balance from account:user2)[0].balance != 10067000000 {
+    throw("User 2 did't get compensated for his VM going down.")
+};
+
+if (select escrow from account:operator2)[0].escrow != 4999933000000 {
+    throw("Operator 2 didn't get punished for not serving a VM.")
+};
+if (select id from deleted_vm:vm1).len() == 0 {
+    throw("VM1 didn't get deleted.")
+}

surql/timer.sql

@@ -0,0 +1,26 @@
+FOR $contract IN (select * from active_vm fetch out) {
+    LET $operator = (select * from $contract.out.operator);
+    LET $node_is_online = $contract.out.connected_at > $contract.out.disconnected_at;
+    LET $price_per_minute = fn::vm_price_per_minute($contract.id);
+    LET $amount_due = IF $price_per_minute > $contract.locked_nano {
+        $contract.locked_nano
+    } ELSE {
+        $price_per_minute
+    };
+    LET $escrow_multiplier = IF $operator.escrow >= 5_000_000_000_000 { 5 } ELSE { 1 };
+    IF $node_is_online {
+        UPDATE $contract.id SET locked_nano -= $amount_due;
+        UPDATE $operator.id SET balance += $amount_due * $escrow_multiplier;
+    } ELSE {
+        LET $compensation = IF $amount_due * 5 > $operator.escrow {
+            $operator.escrow
+        } ELSE {
+            $amount_due * 5
+        };
+        UPDATE $operator.id SET escrow -= $compensation;
+        UPDATE $contract.in SET balance += $compensation;
+    };
+    IF $amount_due >= $contract.locked_nano {
+        fn::delete_vm($contract.id);
+    };
+};