netns: don't repeat cli definitions

1. Saves some code.
2. Guarantees that the netns and no-netns cli defs are always in sync.

modules/bitcoind.nix

@@ -265,20 +265,16 @@ in {
       };
       cli = mkOption {
         type = types.package;
-        default = cfg.cli-nonetns-exec;
+        # Overriden on netns-isolation
+        default = cfg.cliBase;
         description = "Binary to connect with the bitcoind instance.";
       };
-      # Needed because bitcoin-cli commands executed through systemd already
-      # run inside nb-bitcoind, hence they don't need netns-exec prefixed.
-      cli-nonetns-exec = mkOption {
+      cliBase = mkOption {
         readOnly = true;
         type = types.package;
         default = pkgs.writeScriptBin "bitcoin-cli" ''
           exec ${cfg.package}/bin/bitcoin-cli -datadir='${cfg.dataDir}' "$@"
         '';
-        description = ''
-          Binary to connect with the bitcoind instance without netns-exec.
-        '';
       };
       enforceTor =  nix-bitcoin-services.enforceTor;
     };
@@ -315,7 +311,7 @@ in {
         fi
       '';
       postStart = ''
-        cd ${cfg.cli-nonetns-exec}/bin
+        cd ${cfg.cliBase}/bin
         # Poll until bitcoind accepts commands. This can take a long time.
         while ! ./bitcoin-cli getnetworkinfo &> /dev/null; do
           sleep 1
@@ -342,7 +338,7 @@ in {
       bindsTo = [ "bitcoind.service" ];
       after = [ "bitcoind.service" ];
       script = ''
-        cd ${cfg.cli-nonetns-exec}/bin
+        cd ${cfg.cliBase}/bin
         echo "Importing node banlist..."
         cat ${./banlist.cli.txt} | while read line; do
             if ! err=$(eval "$line" 2>&1) && [[ $err != *already\ banned* ]]; then

modules/lightning-loop.nix

@@ -30,10 +30,11 @@ in {
       default = pkgs.writeScriptBin "loop"
       # Switch user because lnd makes datadir contents readable by user only
       ''
-        exec sudo -u lnd ${cfg.package}/bin/loop "$@"
+        ${cfg.cliExec} sudo -u lnd ${cfg.package}/bin/loop "$@"
       '';
       description = "Binary to connect with the lnd instance.";
     };
+    inherit (nix-bitcoin-services) cliExec;
     enforceTor =  nix-bitcoin-services.enforceTor;
   };
 

modules/liquid.nix

@@ -210,17 +210,19 @@ in {
         '';
       };
       cli = mkOption {
+        readOnly = true;
         default = pkgs.writeScriptBin "elements-cli" ''
-          exec ${pkgs.nix-bitcoin.elementsd}/bin/elements-cli -datadir='${cfg.dataDir}' "$@"
+          ${cfg.cliExec} ${pkgs.nix-bitcoin.elementsd}/bin/elements-cli -datadir='${cfg.dataDir}' "$@"
         '';
         description = "Binary to connect with the liquidd instance.";
       };
-      swap-cli = mkOption {
+      swapCli = mkOption {
         default = pkgs.writeScriptBin "liquidswap-cli" ''
-          exec ${pkgs.nix-bitcoin.liquid-swap}/bin/liquidswap-cli -c '${cfg.dataDir}/elements.conf' "$@"
+          ${cfg.cliExec} ${pkgs.nix-bitcoin.liquid-swap}/bin/liquidswap-cli -c '${cfg.dataDir}/elements.conf' "$@"
         '';
         description = "Binary for managing liquid swaps.";
       };
+      inherit (nix-bitcoin-services) cliExec;
       enforceTor =  nix-bitcoin-services.enforceTor;
     };
   };
@@ -229,7 +231,7 @@ in {
     environment.systemPackages = [
       pkgs.nix-bitcoin.elementsd
       (hiPrio cfg.cli)
-      (hiPrio cfg.swap-cli)
+      (hiPrio cfg.swapCli)
     ];
 
     systemd.tmpfiles.rules = [

modules/lnd.nix

@@ -115,11 +115,12 @@ in {
       default = pkgs.writeScriptBin "lncli"
       # Switch user because lnd makes datadir contents readable by user only
       ''
-        exec sudo -u lnd ${cfg.package}/bin/lncli --tlscertpath ${secretsDir}/lnd-cert \
+        ${cfg.cliExec} sudo -u lnd ${cfg.package}/bin/lncli --tlscertpath ${secretsDir}/lnd-cert \
           --macaroonpath '${cfg.dataDir}/chain/bitcoin/mainnet/admin.macaroon' "$@"
       '';
       description = "Binary to connect with the lnd instance.";
     };
+    inherit (nix-bitcoin-services) cliExec;
     enforceTor =  nix-bitcoin-services.enforceTor;
   };
 

modules/netns-isolation.nix

@@ -9,6 +9,7 @@ let
     inherit (v) id;
     address = "169.254.${toString cfg.addressblock}.${toString v.id}";
     availableNetns = availableNetns.${n};
+    netnsName = "nb-${n}";
   }) enabledServices;
 
   # Symmetric netns connection matrix
@@ -42,6 +43,7 @@ let
 
   bridgeIp = "169.254.${toString cfg.addressblock}.10";
 
+  mkCliExec = service: "exec netns-exec ${netns.${service}.netnsName}";
 in {
   options.nix-bitcoin.netns-isolation = {
     enable = mkEnableOption "netns isolation";
@@ -114,7 +116,7 @@ in {
     (let
       makeNetnsServices = n: v: let
         vethName = "nb-veth-${toString v.id}";
-        netnsName = "nb-${n}";
+        inherit (v) netnsName;
         ipNetns = "${ip} -n ${netnsName}";
         netnsIptables = "${ip} netns exec ${netnsName} ${config.networking.firewall.package}/bin/iptables";
       in {
@@ -219,8 +221,10 @@ in {
       rpcallowip = [
         "127.0.0.1"
       ] ++ map (n: "${netns.${n}.address}") netns.bitcoind.availableNetns;
-      cli = pkgs.writeScriptBin "bitcoin-cli" ''
-        netns-exec nb-bitcoind ${config.services.bitcoind.package}/bin/bitcoin-cli -datadir='${config.services.bitcoind.dataDir}' "$@"
+      cli = let
+        inherit (config.services.bitcoind) cliBase;
+      in pkgs.writeScriptBin cliBase.name ''
+        exec netns-exec ${netns.bitcoind.netnsName} ${cliBase}/bin/${cliBase.name} "$@"
       '';
     };
     systemd.services.bitcoind-import-banlist.serviceConfig.NetworkNamespacePath = "/var/run/netns/nb-bitcoind";
@@ -241,12 +245,7 @@ in {
         "127.0.0.1"
       ];
       bitcoind-host = netns.bitcoind.address;
-      cli = pkgs.writeScriptBin "lncli"
-      # Switch user because lnd makes datadir contents readable by user only
-      ''
-        netns-exec nb-lnd sudo -u lnd ${config.services.lnd.package}/bin/lncli --tlscertpath ${config.nix-bitcoin.secretsDir}/lnd-cert \
-          --macaroonpath '${config.services.lnd.dataDir}/chain/bitcoin/mainnet/admin.macaroon' "$@"
-      '';
+      cliExec = mkCliExec "lnd";
     };
 
     services.liquidd = {
@@ -259,12 +258,7 @@ in {
         "127.0.0.1"
       ] ++ map (n: "${netns.${n}.address}") netns.liquidd.availableNetns;
       mainchainrpchost = netns.bitcoind.address;
-      cli = pkgs.writeScriptBin "elements-cli" ''
-        netns-exec nb-liquidd ${pkgs.nix-bitcoin.elementsd}/bin/elements-cli -datadir='${config.services.liquidd.dataDir}' "$@"
-      '';
-      swap-cli = pkgs.writeScriptBin "liquidswap-cli" ''
-        netns-exec nb-liquidd ${pkgs.nix-bitcoin.liquid-swap}/bin/liquidswap-cli -c '${config.services.liquidd.dataDir}/elements.conf' "$@"
-      '';
+      cliExec = mkCliExec "liquidd";
     };
 
     services.electrs = {
@@ -286,13 +280,7 @@ in {
 
     services.nix-bitcoin-webindex.host = netns.nginx.address;
 
-    services.lightning-loop = {
-      cli = pkgs.writeScriptBin "loop"
-      # Switch user because lnd makes datadir contents readable by user only
-      ''
-        netns-exec nb-lightning-loop sudo -u lnd ${config.services.lightning-loop.package}/bin/loop "$@"
-      '';
-    };
+    services.lightning-loop.cliExec = mkCliExec "lightning-loop";
   }
   ]);
 }

modules/nix-bitcoin-services.nix

@@ -55,4 +55,11 @@ with lib;
     set -eo pipefail
     ${src}
   '';
+
+  cliExec = mkOption {
+    # Used by netns-isolation to execute the cli in the service's private netns
+    internal = true;
+    type = types.str;
+    default = "exec";
+  };
 }