Merge pull request #1961 from deitch/compose-examples

add compose dynamic
2025-07-19 09:16:29 +00:00 · 2017-06-04 16:25:04 +01:00 · 2017-06-04 16:25:04 +01:00 · 982bddb185
commit 982bddb185
parent 11b1eb75ad e4512864ac
11 changed files with 356 additions and 0 deletions
--- a/projects/compose/.gitignore
+++ b/projects/compose/.gitignore
@ -0,0 +1,2 @@
+image-cache/
+dist/
--- a/projects/compose/Makefile
+++ b/projects/compose/Makefile
@ -0,0 +1,49 @@
+.PHONY: tag push hash dynamic static cache-images run-static run-dynamic
+
+ORG?=linuxkitprojects
+IMAGE=compose
+DEPS=image/Dockerfile docker-compose.yml image/waitfordocker.sh image/load-images-and-compose.sh
+COMMON_IMAGES := \
+	nginx:alpine \
+	traefik
+
+
+HASH?=$(shell git ls-tree HEAD -- ./image | awk '{print $$3}')
+
+hash:
+	@echo ${HASH}
+
+tag: $(DEPS)
+	docker build --squash --no-cache -t $(ORG)/$(IMAGE):$(HASH) image/
+
+push: tag
+	DOCKER_CONTENT_TRUST=1 docker pull $(ORG)/$(IMAGE):$(HASH) || \
+	DOCKER_CONTENT_TRUST=1 docker push $(ORG)/$(IMAGE):$(HASH)
+
+dynamic:
+	mkdir -p dist
+	moby build -name compose-dynamic -dir dist/ compose-dynamic.yml
+
+static: cache-images
+	mkdir -p dist
+	moby build -name compose-static -dir dist/ compose-static.yml
+
+run-dynamic:
+	linuxkit run dist/compose-dynamic
+
+run-static:
+	linuxkit run dist/compose-static
+
+clean:
+	rm -rf image-cache
+
+image-cache/%.tar:
+	mkdir -p $(dir $@)
+	DOCKER_CONTENT_TRUST=1 docker image pull $(shell basename $@ .tar)
+	docker image save -o $@ $(shell basename $@ .tar)
+
+# use make here for each image rather than a single for loop so we can cache dependencies
+cache-images:
+	for image in $(COMMON_IMAGES) ; do \
+		make "image-cache/$${image}.tar" ; \
+	done
--- a/projects/compose/README.md
+++ b/projects/compose/README.md
@ -0,0 +1,57 @@
+# Compose Project
+
+The purpose of this project is to show how moby and linuxkit can be used to build a runnable linuxkit image with compose-style apps ready-to-run.
+
+The apps are simple:
+
+* nginx serving app A
+* nginx serving app B
+* traefik routing on the basis of hostname between apps A and B
+
+
+## Compose Methods
+We provide samples of two methods for using compose: dynamic and static.
+
+Both methods use the image `linuxkit/compose`. The image does the following:
+
+1. Wait for compose to be ready.
+2. If there are any tar files available in `/images/*.tar`, treat them as tarred up docker images and load them into docker via `docker load ...`
+3. Run `docker compose ...`
+
+The only difference between dynamic and static is whether or not container images are pre-loaded in the linuxkit image.
+
+* Compose: the `linuxkit/compose` image looks for a compose file at `/compose/docker-compose.yml`
+* Images: the `linuxkit/compose` image looks for tarred container images at `/compose/images/*.tar`
+
+### Dynamic
+Dynamic loads the _compose_ config into the linuxkit image at build time. Container images are not pre-loaded, and thus docker loads the container images from the registry **at run-time**. This is no different than doing the following:
+
+1. Using the docker linuxkit image
+2. Connecting remotely via the docker API
+3. Running the compose file remotely
+
+Except that the compose is run at launch time, and there is no need for a remote connection to the docker API.
+
+It works by loading the `docker-compose.yml` file onto the linuxkit image, and making it available to the `compose` container image via a bind-mount.
+
+To build a dynamic image, do `make dynamic`. To run it, do `make run-dynamic`.
+
+### Static
+Static loads the _compose_ config **and** the container _images_ into the linuxkit image at build time. When run, docker loads the images from its local cache and does not depend on access to a registry.
+
+It works by loading the `docker-compose.yml` file onto the linuxkit image and tarred up container image files. It then makes them available to the `compose` container image via bind-mounts.
+
+
+To build a static image, do `make static`. To run it, do `make run-static`.
+
+Static images pre-load them by doing:
+
+1. Download the image locally `docker image pull <image>`
+2. Save the image to a local tar file `docker image save -o <image> <imagename>.tar`
+3. copy the tar file to the container image
+4. When starting the container from the image with the files, load the images into docker before running compose: `docker image load -i <image> && rm -f <imagename>.tar`
+
+### Conversion
+A final option would be converting all of the containers defined in a `docker-compose.yml` into linuxkit `services`. It also would require setting up appropriate networks and other services provided by docker when running compose.
+
+An example may be added in the future.
--- a/projects/compose/compose-dynamic.yml
+++ b/projects/compose/compose-dynamic.yml
@ -0,0 +1,56 @@
+kernel:
+  image: "linuxkit/kernel:4.9.x"
+  cmdline: "console=ttyS0 page_poison=1"
+init:
+  - linuxkit/init:1b8a7e394d2ec2f1fdb4d67645829d1b5bdca037
+  - linuxkit/runc:3a4e6cbf15470f62501b019b55e1caac5ee7689f
+  - linuxkit/containerd:b1766e4c4c09f63ac4925a6e4612852a93f7e73b
+  - linuxkit/ca-certificates:75cf419fb58770884c3464eb687ec8dfc704169d
+onboot:
+  - name: sysctl
+    image: "linuxkit/sysctl:3aa6bc663c2849ef239be7d941d3eaf3e6fcc018"
+  - name: sysfs
+    image: linuxkit/sysfs:1244c5a86dfa2318c4e304af68d37e12367e1b7f
+  - name: dhcpcd
+    image: "linuxkit/dhcpcd:7d2b8aaaf20c24ad7d11a5ea2ea5b4a80dc966f1"
+    command: ["/sbin/dhcpcd", "--nobackground", "-f", "/dhcpcd.conf", "-1"]
+  - name: binfmt
+    image: "linuxkit/binfmt:8ac5535f57f0c6f5fe88317b9d22a7677093c765"
+  - name: format
+    image: "linuxkit/format:180cb2dc1de5e60373385080f8148abf10a3afac"
+  - name: mount
+    image: "linuxkit/mount:ff5338822f20375b8913f5a80f9ed4f6ea9a592b"
+    command: ["/mount.sh", "/var/lib/docker"]
+services:
+  - name: rngd
+    image: "linuxkit/rngd:1fa4de44c961bb5075647181891a3e7e7ba51c31"
+  - name: ntpd
+    image: "linuxkit/openntpd:45deeb05f736162d941c9bf494983f655ab80aa5"
+  - name: docker
+    image: "linuxkit/docker-ce:668d62da6e3da081a8f8aca7db3e2a98adf5da59"
+    capabilities:
+     - all
+    net: host
+    mounts:
+     - type: cgroup
+       options: ["rw","nosuid","noexec","nodev","relatime"]
+    binds:
+     - /var/lib/docker:/var/lib/docker
+     - /lib/modules:/lib/modules
+     - /var/run:/var/run
+     - /var/html:/var/html
+  - name: compose
+    image: "linuxkitprojects/compose:0535e78608f57702745dfd56fbe78d28d237e469"
+    binds:
+     - /var/run:/var/run
+     - /var/compose:/compose
+files:
+  - path: var/html/a/index.html
+    source: html-a.html
+  - path: var/html/b/index.html
+    source: html-b.html
+  - path: var/compose/docker-compose.yml
+    source: docker-compose.yml
+trust:
+  org:
+    - linuxkit
--- a/projects/compose/compose-static.yml
+++ b/projects/compose/compose-static.yml
@ -0,0 +1,60 @@
+kernel:
+  image: "linuxkit/kernel:4.9.x"
+  cmdline: "console=ttyS0 page_poison=1"
+init:
+  - linuxkit/init:1b8a7e394d2ec2f1fdb4d67645829d1b5bdca037
+  - linuxkit/runc:3a4e6cbf15470f62501b019b55e1caac5ee7689f
+  - linuxkit/containerd:b1766e4c4c09f63ac4925a6e4612852a93f7e73b
+  - linuxkit/ca-certificates:75cf419fb58770884c3464eb687ec8dfc704169d
+onboot:
+  - name: sysctl
+    image: "linuxkit/sysctl:3aa6bc663c2849ef239be7d941d3eaf3e6fcc018"
+  - name: sysfs
+    image: linuxkit/sysfs:1244c5a86dfa2318c4e304af68d37e12367e1b7f
+  - name: dhcpcd
+    image: "linuxkit/dhcpcd:7d2b8aaaf20c24ad7d11a5ea2ea5b4a80dc966f1"
+    command: ["/sbin/dhcpcd", "--nobackground", "-f", "/dhcpcd.conf", "-1"]
+  - name: binfmt
+    image: "linuxkit/binfmt:8ac5535f57f0c6f5fe88317b9d22a7677093c765"
+  - name: format
+    image: "linuxkit/format:180cb2dc1de5e60373385080f8148abf10a3afac"
+  - name: mount
+    image: "linuxkit/mount:ff5338822f20375b8913f5a80f9ed4f6ea9a592b"
+    command: ["/mount.sh", "/var/lib/docker"]
+services:
+  - name: rngd
+    image: "linuxkit/rngd:1fa4de44c961bb5075647181891a3e7e7ba51c31"
+  - name: ntpd
+    image: "linuxkit/openntpd:45deeb05f736162d941c9bf494983f655ab80aa5"
+  - name: docker
+    image: "linuxkit/docker-ce:668d62da6e3da081a8f8aca7db3e2a98adf5da59"
+    capabilities:
+     - all
+    net: host
+    mounts:
+     - type: cgroup
+       options: ["rw","nosuid","noexec","nodev","relatime"]
+    binds:
+     - /var/lib/docker:/var/lib/docker
+     - /lib/modules:/lib/modules
+     - /var/run:/var/run
+     - /var/html:/var/html
+  - name: compose
+    image: "linuxkitprojects/compose:0535e78608f57702745dfd56fbe78d28d237e469"
+    binds:
+     - /var/run:/var/run
+     - /var/compose:/compose
+files:
+  - path: var/html/a/index.html
+    source: html-a.html
+  - path: var/html/b/index.html
+    source: html-b.html
+  - path: var/compose/docker-compose.yml
+    source: docker-compose.yml
+  - path: var/compose/images/nginx:alpine.tar
+    source: image-cache/nginx:alpine.tar
+  - path: var/compose/images/traefik.tar
+    source: image-cache/traefik.tar
+trust:
+  org:
+    - linuxkit
--- a/projects/compose/docker-compose.yml
+++ b/projects/compose/docker-compose.yml
@ -0,0 +1,25 @@
+version: '2.1'
+services:
+  a:
+    image: nginx:alpine
+    volumes:
+      - /var/html/a:/usr/share/nginx/html
+    labels:
+      - "traefik.backend=a"
+      - "traefik.frontend.rule=Host:a.docker.localhost"
+  b:
+    image: nginx:alpine
+    volumes:
+      - /var/html/b:/usr/share/nginx/html
+    labels:
+      - "traefik.backend=b"
+      - "traefik.frontend.rule=Host:b.docker.localhost"
+      - "traefik.port=80"
+  proxy:
+    image: traefik
+    command: --web --docker --docker.domain=docker.localhost --logLevel=DEBUG
+    ports:
+      - "80:80"
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock
+      - /dev/null:/traefik.toml
--- a/projects/compose/html-a.html
+++ b/projects/compose/html-a.html
@ -0,0 +1,8 @@
+<html>
+<head>
+	<title>A index</title>
+</head>
+<body>
+	This is the index for A
+</body>
+</html>
--- a/projects/compose/html-b.html
+++ b/projects/compose/html-b.html
@ -0,0 +1,8 @@
+<html>
+<head>
+	<title>B index</title>
+</head>
+<body>
+	This is the index for B
+</body>
+</html>
--- a/projects/compose/image/Dockerfile
+++ b/projects/compose/image/Dockerfile
@ -0,0 +1,27 @@
+FROM docker/compose:1.13.0
+# because compose requires all sorts of dynamic libs, including glibc, it is much easier to
+#   add docker client to compose than the reverse
+
+ENV DOCKER_BUCKET get.docker.com
+ENV DOCKER_VERSION 17.05.0-ce
+ENV DOCKER_SHA256 340e0b5a009ba70e1b644136b94d13824db0aeb52e09071410f35a95d94316d9
+
+# we need docker compose and docker load
+# also need curl to test availability of docker API
+RUN apk add --update curl
+
+# we only need the client
+RUN set -x \
+	&& curl -fSL "https://${DOCKER_BUCKET}/builds/Linux/x86_64/docker-${DOCKER_VERSION}.tgz" -o docker.tgz \
+	&& echo "${DOCKER_SHA256} *docker.tgz" | sha256sum -c - \
+	&& tar -xzvf docker.tgz \
+	&& mv docker/docker /usr/bin/ \
+	&& rm -rf docker docker.tgz \
+	&& docker -v
+
+
+RUN mkdir -p /compose /app
+WORKDIR /app
+COPY . /app
+ENTRYPOINT ["/app/waitfordocker.sh"]
+CMD ["/app/load-images-and-compose.sh"]
--- a/projects/compose/image/load-images-and-compose.sh
+++ b/projects/compose/image/load-images-and-compose.sh
@ -0,0 +1,17 @@
+#!/bin/sh
+set -e
+
+#########
+#
+# load any cached mounted images, and run compose
+#
+########
+
+[ -n "$DEBUG" ] && set -x
+
+for image in /compose/images/*.tar ; do
+	docker image load -i $image && rm -f $image
+done
+
+
+docker-compose -f /compose/docker-compose.yml up -d
--- a/projects/compose/image/waitfordocker.sh
+++ b/projects/compose/image/waitfordocker.sh
@ -0,0 +1,47 @@
+#!/bin/sh
+set -e
+
+#########
+#
+# wait for docker socket to be ready, then run the rest of the command
+#
+########
+RETRIES=${RETRIES:-"-1"}
+WAIT=${WAIT:=10}
+[ -n "$DEBUG" ] && set -x
+
+# keep retrying until docker is ready or we hit our limut
+retry_or_fail() {
+  local retry_count=0
+  local success=1
+  local cmd=$1
+  local retryMax=$2
+  local retrySleep=$3
+  local message=$4
+  until [[ $retry_count -ge $retryMax && $retryMax -ne -1 ]]; do
+    echo "trying to $message"
+    set +e
+    $cmd
+    success=$?
+    set -e
+    [[ $success == 0 ]] && break
+    retry_count=$(( $retry_count+1 )) || true
+    echo "attempt number $retry_count failed to $message, sleeping $retrySleep seconds..."
+    sleep $retrySleep
+  done
+  # did we succeed?
+  if [[ $success != 0 ]]; then
+    echo "failed to $message after $retryMax tries. Exiting..." >&2
+    exit 1
+  fi
+}
+
+connect_to_docker() {
+  [ -S /var/run/docker.sock ] || return 1
+  curl --unix-socket /var/run/docker.sock http://localhost/containers/json >/dev/null 2>&1 || return 1
+}
+# try to connect to docker
+retry_or_fail connect_to_docker $RETRIES $WAIT "connect to docker"
+
+# if we got here, we succeeded
+$@