dockerTools.buildImage: make VM memSize configurable

Fixes #186752. This adds buildVMMemorySize (defaults to 512 MiB) to
buildImage, which is passed to vm.runInLinuxVM. This is needed for
larger base images, which may otherwise cause container build failures
due to OOM in the VM.

doc/builders/images/dockertools.section.md

@@ -36,6 +36,9 @@ buildImage {
     WorkingDir = "/data";
     Volumes = { "/data" = { }; };
   };
+
+  diskSize = 1024;
+  buildVMMemorySize = 512;
 }
 ```
 
@@ -59,6 +62,10 @@ The above example will build a Docker image `redis/latest` from the given base i
 
 - `config` is used to specify the configuration of the containers that will be started off the built image in Docker. The available options are listed in the [Docker Image Specification v1.2.0](https://github.com/moby/moby/blob/master/image/spec/v1.2.md#image-json-field-descriptions).
 
+- `diskSize` is used to specify the disk size of the VM used to build the image in megabytes. By default it's 1024 MiB.
+
+- `buildVMMemorySize` is used to specify the memory size of the VM to build the image in megabytes. By default it's 512 MiB.
+
 After the new layer has been created, its closure (to which `contents`, `config` and `runAsRoot` contribute) will be copied in the layer itself. Only new dependencies that are not already in the existing layers will be copied.
 
 At the end of the process, only one new single layer will be produced and added to the resulting image.

pkgs/build-support/docker/default.nix

@@ -205,6 +205,7 @@ rec {
     , fromImageName ? null
     , fromImageTag ? null
     , diskSize ? 1024
+    , buildVMMemorySize ? 512
     , preMount ? ""
     , postMount ? ""
     , postUmount ? ""
@@ -218,6 +219,7 @@ rec {
               destination = "./image";
             };
             inherit fromImage fromImageName fromImageTag;
+            memSize = buildVMMemorySize;
 
             nativeBuildInputs = [ util-linux e2fsprogs jshon rsync jq ];
           } ''
@@ -407,6 +409,8 @@ rec {
       fromImageTag ? null
     , # How much disk to allocate for the temporary virtual machine.
       diskSize ? 1024
+    , # How much memory to allocate for the temporary virtual machine.
+      buildVMMemorySize ? 512
     , # Commands (bash) to run on the layer; these do not require sudo.
       extraCommands ? ""
     }:
@@ -418,7 +422,7 @@ rec {
     runWithOverlay {
       name = "docker-layer-${name}";
 
-      inherit fromImage fromImageName fromImageTag diskSize;
+      inherit fromImage fromImageName fromImageTag diskSize buildVMMemorySize;
 
       preMount = lib.optionalString (copyToRoot != null && copyToRoot != [ ]) ''
         echo "Adding contents..."
@@ -517,6 +521,8 @@ rec {
       runAsRoot ? null
     , # Size of the virtual machine disk to provision when building the image.
       diskSize ? 1024
+    , # Size of the virtual machine memory to provision when building the image.
+      buildVMMemorySize ? 512
     , # Time of creation of the image.
       created ? "1970-01-01T00:00:01Z"
     , # Deprecated.
@@ -563,7 +569,7 @@ rec {
           mkRootLayer {
             name = baseName;
             inherit baseJson fromImage fromImageName fromImageTag
-              keepContentsDirlinks runAsRoot diskSize
+              keepContentsDirlinks runAsRoot diskSize buildVMMemorySize
               extraCommands;
             copyToRoot = rootContents;
           };