Update state directory defaults

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

README.md

@@ -108,48 +108,17 @@ buildctl du -v
 
 #### Running containerized buildkit
 
-buildkit daemon supports communicating with clients over TCP. This is supports some use cases like:
-
-* Docker for Mac or Windows users which cannot yet run natively buildkit daemon on their platform,
-* Centralized daemon for remote build scripts execution in a team settings
-* ...
+buildkit can be also used by running the `buildd` daemon inside a Docker container and accessing it remotely. The client tool `buildctl` is also available for Mac and Windows.
 
 To run daemon in a container:
 
 ```
-$ docker run --rm --privileged -p 12345:12345 --tmpfs /tmp  buildkit:buildd-standalone buildd-standalone --addr tcp://0.0.0.0:12345 --root /tmp/buildkit
+docker run --d --privileged -p 1234:1234 tonistiigi/buildkit:standalone --addr tcp://0.0.0.0:1234
+export BUILDKIT_HOST=tcp://0.0.0.0:1234
+buildctl build --help
 ```
 
-Notes:
-
-* `--privileged` is needed to grant [enough rights](https://docs.docker.com/engine/reference/run/#runtime-privilege-and-linux-capabilities) to buildkit
-* You need to make sure the --root directory exists on a filesystem that is supported by overlay filesystem. e.g. tmpfs, ext4, xfs.
-
-Build a script:
-
-```
-$ go build examples/buildkit0
-```
-
-Run build script:
-
-On MacOS:
-
-```
-$ ./buildkit0 | ./bin/buildctl-darwin --addr tcp://localhost:12345 build
-```
-
-On Windows:
-
-```
-$ ./buildkit0 | ./bin/buildctl.exe --addr tcp://localhost:12345 build
-```
-
-On Linux:
-
-```
-$ ./buildkit0 | ./bin/buildctl --addr tcp://localhost:12345 build
-```
+The `tonistiigi/buildkit:standalone` image can be built locally using the Dockerfile in `./hack/dockerfiles/test.Dockerfile`.
 
 
 #### Supported runc version

cmd/buildctl/main.go

@@ -16,6 +16,11 @@ func main() {
 	app.Name = "buildctl"
 	app.Usage = "build utility"
 
+	defaultAddress := os.Getenv("BUILDKIT_HOST")
+	if defaultAddress == "" {
+		defaultAddress = appdefaults.Address
+	}
+
 	app.Flags = []cli.Flag{
 		cli.BoolFlag{
 			Name:  "debug",
@@ -24,7 +29,7 @@ func main() {
 		cli.StringFlag{
 			Name:  "addr",
 			Usage: "listening address",
-			Value: appdefaults.Address,
+			Value: defaultAddress,
 		},
 	}
 

hack/dockerfiles/test.Dockerfile

@@ -1,5 +1,6 @@
 ARG RUNC_VERSION=e775f0fba3ea329b8b766451c892c41a3d49594d
 ARG CONTAINERD_VERSION=d1e11f17ec7b325f89608dd46c128300b8727d50
+ARG BUILDKIT_TARGET=standalone
 
 FROM golang:1.8-alpine@sha256:2287e0e274c1d2e9076c1f81d04f1a63c86b73c73603b09caada5da307a8f86d AS gobuild-base
 RUN apk add --no-cache g++ linux-headers
@@ -54,3 +55,23 @@ RUN go build -o /buildctl.exe ./cmd/buildctl
 
 FROM cross-windows AS buildd.exe
 RUN go build -o /buildd.exe ./cmd/buildd
+
+# Copy together all binaries needed for standalone mode
+FROM alpine AS buildkit-standalone
+COPY --from=runc /usr/bin/runc /usr/bin/
+COPY --from=buildd-standalone /usr/bin/buildd-standalone /usr/bin/
+COPY --from=buildctl /usr/bin/buildctl /usr/bin/
+ENTRYPOINT ["buildd-standalone"]
+
+# Copy together all binaries for containerd mode
+FROM alpine AS buildkit-containerd
+COPY --from=buildd-containerd /usr/bin/buildd-containerd /usr/bin/
+COPY --from=buildctl /usr/bin/buildctl /usr/bin/
+COPY --from=runc /usr/bin/runc /usr/bin/
+COPY --from=containerd /go/src/github.com/containerd/containerd/bin/containerd /usr/bin/
+COPY --from=containerd /go/src/github.com/containerd/containerd/bin/containerd-shim /usr/bin/
+ENTRYPOINT ["buildd-containerd"]
+
+FROM buildkit-${BUILDKIT_TARGET}
+RUN apk add --no-cache git
+VOLUME /var/lib/buildkit

util/appdefaults/appdefaults_unix.go

@@ -4,5 +4,5 @@ package appdefaults
 
 const (
 	Address = "unix:///run/buildkit/buildd.sock"
-	Root    = ".buildstate"
+	Root    = "/var/lib/buildkit"
 )