Initial commit

GLOCKFILE

@@ -0,0 +1,3 @@
+github.com/ActiveState/tail 068b72961a6bc5b4a82cf4fc14ccc724c0cfa73a
+github.com/howeyc/fsnotify 6b1ef893dc11e0447abda6da20a5203481878dda
+gopkg.in/tomb.v1 c131134a1947e9afd9cecfe11f4c6dff0732ae58

Makefile

@@ -0,0 +1,21 @@
+.SILENT :
+.PHONY : dockerize clean fmt
+
+TAG:=`git describe --abbrev=0 --tags`
+LDFLAGS:=-X main.buildVersion $(TAG)
+
+all: dockerize
+
+dockerize:
+	echo "Building dockerize"
+	go install -ldflags "$(LDFLAGS)"
+
+dist-clean:
+	rm -rf dist
+	rm -f dockerize-linux-*.tar.gz
+
+dist: dist-clean
+	mkdir -p dist/linux/amd64 && GOOS=linux GOARCH=amd64 go build -ldflags "$(LDFLAGS)" -o dist/linux/amd64/dockerize
+
+release: dist
+	tar -cvzf dockerize-linux-amd64-$(TAG).tar.gz -C dist/linux/amd64 dockerize

README.md

@@ -0,0 +1,95 @@
+dockerize
+=============
+
+Utility to simplify running applications in docker containers.
+
+dockerize is a utility to simplify running applications in docker containers.  It allows you
+to generate application configuration files at container startup time from templates and
+container environment variables.  It also allows log files to be tailed to stdout and/or
+stderr.
+
+The typical use case for dockerize is when you have an application that has one or more
+configuration files and you would like to control some of the values using environment variables.
+
+For example, a Python application using Sqlalchemy may be able to use environment variables directly.
+It may require that the database URL be read from a python settings file with a variable named
+`SQLALCHEMY_DATABASE_URI`.  dockerize allows you to set an environment variable such as
+`DATABASE_URL` and update the python file when the container starts.
+
+Another use case is when the application logs to specific files on the filesystem and not stdout
+or stderr.  This makes it difficult to troubleshoot the container using the `docker logs` command.
+For example, nginx will log to `/var/log/nginx/access.log' and
+'/var/log/nginx/error.log' by default.  While you can sometimes work around this, it's tedious to find
+the a solution for every application.  dockerize allows you to specify which logs files should
+be tailed and where they should be sent.
+
+
+## Installation
+
+Download the latest version in your container:
+
+* [linux/amd64](https://github.com/jwilder/dockerize/releases/download/v0.0.1/dockerize-linux-amd64-v0.0.1.tar.gz)
+
+For Ubuntu Images:
+
+```
+RUN apt-get update && apt-get install -y wget
+RUN wget https://github.com/jwilder/dockerize/releases/download/v0.0.1/dockerize-linux-amd64-v0.0.1.tar.gz
+RUN tar -C /usr/local/bin -xzvf dockerize-linux-amd64-v0.0.1.tar.gz
+```
+
+## Usage
+
+dockerize works by wrapping the call to your application using the `ENTRYPOINT` or `CMD` directives.
+
+This would generate `/etc/nginx/nginx.conf` from the template located at `/etc/nginx/nginx.tmpl` and
+send `/var/log/nginx/access.log' to `STDOUT` and `/var/log/nginx/error.log` to `STDERR` after running
+`nginx`.
+
+```
+CMD dockerize -template /etc/nginx/nginx.tmpl:/etc/nginx/nginx.conf -stdout /var/log/nginx/access.log -stderr /var/log/nginx/error.log nginx
+```
+
+### Command-line Options
+
+You can specify multiple template by passing using `-template` multiple times:
+
+```
+$ dockerize -template template1.tmpl:file1.cfg -template template2.tmpl:file3
+
+```
+
+You can tail multiple files to `STDOUT` and `STDERR` by passing the options multiple times.
+
+```
+$ dockerize -stdout info.log -stdout perf.log
+
+```
+
+If your file uses `{{` and `}}` as part of it's syntax, you can change the template escape characters using the `-delims`.
+
+```
+$ dockerize -delims "<%:%>"
+```
+
+## Using Templates
+
+Templates use Golang [text/template](http://golang.org/pkg/text/template/). You can access environment
+variables within a template with `.Env`.
+
+```
+{{ .Env.PATH }} is my path
+```
+
+There are a few built in functions as well:
+
+  * `default` - Returns a default value for one that does not exist
+  * `contains` - Returns true if a string is within another string
+  * `exists` - Determines if a file path exists or not
+  * `split` - Splits a string into an array using a separator string
+  * `replace` - Replaces all occurences of a string within another string
+  * `parseUrl`- Parses a URL into it's protocol, scheme, host, etc. parts.
+
+## License
+
+MIT

dockerize.go

@@ -0,0 +1,94 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"strings"
+	"sync"
+)
+
+type sliceVar []string
+
+type Context struct {
+}
+
+func (c *Context) Env() map[string]string {
+	env := make(map[string]string)
+	for _, i := range os.Environ() {
+		sep := strings.Index(i, "=")
+		env[i[0:sep]] = i[sep+1:]
+	}
+	return env
+}
+
+var (
+	buildVersion string
+	version      bool
+	wg           sync.WaitGroup
+
+	templatesFlag  sliceVar
+	stdoutTailFlag sliceVar
+	stderrTailFlag sliceVar
+	delimsFlag     string
+	delims         []string
+)
+
+func (s *sliceVar) Set(value string) error {
+	*s = append(*s, value)
+	return nil
+}
+
+func (s *sliceVar) String() string {
+	return strings.Join(*s, ",")
+}
+
+func main() {
+
+	flag.BoolVar(&version, "version", false, "show version")
+	flag.Var(&templatesFlag, "template", "Template (/template:/dest). Can be passed multiple times")
+	flag.Var(&stdoutTailFlag, "stdout", "Tails a file to stdout. Can be passed multiple times")
+	flag.Var(&stderrTailFlag, "stderr", "Tails a file to stderr. Can be passed multiple times")
+	flag.StringVar(&delimsFlag, "delims", "", `template tag delimiters. default "{{":"}}" `)
+
+	flag.Parse()
+
+	if version {
+		fmt.Println(buildVersion)
+		return
+	}
+
+	if flag.NArg() == 0 {
+		log.Fatalln("no command specified")
+	}
+
+	if delimsFlag != "" {
+		delims = strings.Split(delimsFlag, ":")
+		if len(delims) != 2 {
+			log.Fatalf("bad delimiters argument: %s. expected \"left:right\"", delimsFlag)
+		}
+	}
+	for _, t := range templatesFlag {
+		parts := strings.Split(t, ":")
+		if len(parts) != 2 {
+			log.Fatalf("bad template argument: %s. expected \"/template:/dest\"", t)
+		}
+		generateFile(parts[0], parts[1])
+	}
+
+	wg.Add(1)
+	go runCmd(flag.Arg(0), flag.Args()[1:]...)
+
+	for _, out := range stdoutTailFlag {
+		wg.Add(1)
+		go tailFile(out, os.Stdout)
+	}
+
+	for _, err := range stderrTailFlag {
+		wg.Add(1)
+		go tailFile(err, os.Stderr)
+	}
+
+	wg.Wait()
+}

examples/nginx/Dockerfile

@@ -0,0 +1,20 @@
+FROM ubuntu:14.04
+MAINTAINER Jason Wilder [email protected]
+
+# Install Nginx.
+RUN echo "deb http://ppa.launchpad.net/nginx/stable/ubuntu trusty main" > /etc/apt/sources.list.d/nginx-stable-trusty.list
+RUN echo "deb-src http://ppa.launchpad.net/nginx/stable/ubuntu trusty main" >> /etc/apt/sources.list.d/nginx-stable-trusty.list
+RUN apt-key adv --keyserver keyserver.ubuntu.com --recv-keys C300EE8C
+RUN apt-get update
+RUN apt-get install -y  wget nginx
+
+RUN wget https://github.com/jwilder/dockerize/releases/download/v0.0.1/dockerize-linux-amd64-v0.0.1.tar.gz
+RUN tar -C /usr/local/bin -xvzf dockerize-linux-amd64-v0.0.1.tar.gz
+
+RUN echo "daemon off;" >> /etc/nginx/nginx.conf
+
+ADD default.tmpl /etc/nginx/sites-available/default.tmpl
+
+EXPOSE 80
+
+CMD dockerize -template /etc/nginx/sites-available/default.tmpl:/etc/nginx/sites-available/default -stdout /var/log/nginx/access.log -stderr /var/log/nginx/error.log nginx

examples/nginx/default.tmpl

@@ -0,0 +1,18 @@
+server {
+    listen 80 default_server;
+    listen [::]:80 default_server ipv6only=on;
+
+    root /usr/share/nginx/html;
+    index index.html index.htm;
+
+    # Make site accessible from http://localhost/
+    server_name localhost;
+
+    location / {
+      access_log off;
+      proxy_pass {{ .Env.PROXY_URL }};
+      proxy_set_header X-Real-IP $remote_addr;
+      proxy_set_header Host $host;
+      proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
+    }
+}

exec.go

@@ -0,0 +1,20 @@
+package main
+
+import (
+	"log"
+	"os"
+	"os/exec"
+)
+
+func runCmd(cmd string, args ...string) {
+
+	//FIXME: forward signals
+	process := exec.Command(cmd, args...)
+	process.Stdin = os.Stdin
+	process.Stdout = os.Stdout
+	process.Stderr = os.Stderr
+	err := process.Run()
+	if err != nil {
+		log.Fatalf("error running command: %s, %s\n", cmd, err)
+	}
+}

tail.go

@@ -0,0 +1,25 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/ActiveState/tail"
+)
+
+func tailFile(file string, dest *os.File) {
+	defer wg.Done()
+	t, err := tail.TailFile(file, tail.Config{
+		Follow: true,
+		ReOpen: true,
+		//Poll:   true,
+		Logger: tail.DiscardingLogger,
+	})
+	if err != nil {
+		log.Fatalf("unable to tail %s: %s", "foo", err)
+	}
+	for line := range t.Lines {
+		fmt.Fprintln(dest, line.Text)
+	}
+}