singularity: init 2.2

2016-11-15 09:11:53 +11:00
parent 7f71b89454
commit 04121437be
4 changed files with 130 additions and 0 deletions
@@ -0,0 +1,100 @@
+{ runCommand
+, stdenv
+, storeDir ? builtins.storeDir
+, writeScript
+, singularity
+, writeReferencesToFile
+, bash
+, vmTools
+, gawk
+, utillinux
+, e2fsprogs
+, squashfsTools }:
+
+rec {
+  shellScript = name: text:
+    writeScript name ''
+      #!${stdenv.shell}
+      set -e
+      ${text}
+    '';
+
+  mkLayer = {
+    name,
+    contents ? [],
+  }:
+    runCommand "singularity-layer-${name}" {
+      inherit contents;
+    } ''
+      mkdir $out
+      for f in $contents ; do
+        cp -ra $f $out/
+      done
+    '';
+
+  buildImage = {
+    name,
+    contents ? [],
+    diskSize ? 1024,
+    runScript ? "#!${stdenv.shell}\nexec /bin/sh",
+    runAsRoot ? null,
+    extraSpace ? 0
+  }:
+    let layer = mkLayer {
+          inherit name;
+          contents = contents ++ [ bash runScriptFile ];
+          };
+        runAsRootFile = shellScript "run-as-root.sh" runAsRoot;
+        runScriptFile = shellScript "run-script.sh" runScript;
+        result = vmTools.runInLinuxVM (
+          runCommand "singularity-image-${name}.img" {
+            buildInputs = [ singularity e2fsprogs utillinux gawk ];
+            layerClosure = writeReferencesToFile layer;
+            preVM = vmTools.createEmptyImage {
+              size = diskSize;
+              fullName = "singularity-run-disk";
+            };
+          }
+          ''
+            rm -rf $out
+            mkdir disk
+            mkfs -t ext3 -b 4096 /dev/${vmTools.hd}
+            mount /dev/${vmTools.hd} disk
+            cd disk
+
+            # Run root script
+            ${stdenv.lib.optionalString (runAsRoot != null) ''
+              mkdir -p ./${storeDir}
+              mount --rbind ${storeDir} ./${storeDir}
+              unshare -imnpuf --mount-proc chroot ./ ${runAsRootFile}
+              umount -R ./${storeDir}
+            ''}
+
+            # Build /bin and copy across closure
+            mkdir -p bin nix/store
+            for f in $(cat $layerClosure) ; do
+              cp -ar $f ./$f
+              for f in $f/bin/* ; do
+                if [ ! -e bin/$(basename $f) ] ; then
+                  ln -s $f bin/
+                fi
+              done
+            done
+
+            # Create runScript
+            ln -s ${runScriptFile} singularity
+
+            # Size calculation
+            cd ..
+            umount disk
+            size=$(resize2fs -P /dev/${vmTools.hd} | awk '{print $NF}')
+            mount /dev/${vmTools.hd} disk
+            cd disk
+
+            export PATH=$PATH:${e2fsprogs}/bin/
+            singularity create -s $((1 + size * 4 / 1024 + ${toString extraSpace})) $out
+            tar -c . | singularity import $out
+          '');
+
+    in result;
+}