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https://github.com/zekiunal/swarm-template
Generic template rendering for Docker Swarm Mode
https://github.com/zekiunal/swarm-template
devops docker service-discovery swarm-mode swarm-template templating
Last synced: 15 days ago
JSON representation
Generic template rendering for Docker Swarm Mode
- Host: GitHub
- URL: https://github.com/zekiunal/swarm-template
- Owner: zekiunal
- License: apache-2.0
- Created: 2016-12-18T15:18:01.000Z (almost 8 years ago)
- Default Branch: v2
- Last Pushed: 2017-07-23T08:35:41.000Z (over 7 years ago)
- Last Synced: 2024-08-02T15:48:54.896Z (4 months ago)
- Topics: devops, docker, service-discovery, swarm-mode, swarm-template, templating
- Language: Go
- Homepage:
- Size: 22.5 KB
- Stars: 7
- Watchers: 2
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
Swarm Template
===============
The daemon swarm-template queries a Docker Swarm API and updates any number of specified templates on the file system.
swarm-template can optionally run arbitrary commands when the update process completes.
Installation
------------
You can download a released `swarm-template` artifact from
[the Swarm Template release page](https://github.com/zekiunal/swarm-template/releases/). If you wish to compile from source,
please see the instructions in the [Contributing](#contributing) section.
Usage
-----
### Command Line
The CLI interface supports all of the options detailed above.
#### Help
```shell
# ./swarm-template -h
Usage: swarm-template [options]
Generate files from docker swarm api
Options:
-cmd restart xyz
run command after template is regenerated (e.g restart xyz) (default "true")
-host string
swarm manager address. (default "unix:///var/run/docker.sock")
-interval int
notify command interval (secs) (default 1)
-target_file string
path to a write the template. (default "example/template.cfg")
-template_file string
path to a template to generate (default "example/template.tmpl")
-version
show version
For more information, see https://github.com/zekiunal/swarm-template
```
#### Run
```shell
$ ./swarm-template \
-host="tcp://0.0.0.0:2375"
-template_file="example/template.tmpl" \
-target_file="example/target_file" \
-cmd="/usr/sbin/nginx -s reload" \
```
### Example
#### 1 - Create example services
```shell
docker service rm api-example-com_v1-000 api-example-com_v1-001 anotherapi-example-com_v1-0000 anotherapi-example-com_v1-0001 anotherapi-example-com_v1-0002 logs-example-com static-example-com www-example-com
docker service create --name www-example-com --label st.tags="backend,development,public" --label st.version="1.000" --label st.group=www.example.com alpine ping docker.com
docker service create --name static-example-com --label st.tags="static,development,public" --label st.version="1.000" --label st.group=static.example.com alpine ping docker.com
docker service create --name logs-example-com --label st.tags="backend,development,internal" --label st.version="1.000" --label st.group=logs.example.com alpine ping docker.com
docker service create --name api-example-com_v1-000 --label st.tags="backend,development,public,internal,api" --label st.version="1.000" --label st.group=api.example.com alpine ping docker.com
docker service create --name api-example-com_v1-001 --label st.tags="backend,development,public,internal,api" --label st.version="1.001" --label st.group=api.example.com alpine ping docker.com
docker service create --name anotherapi-example-com_v1-0000 --label st.tags="backend,development,public,internal,api" --label st.version="1.000" --label st.group=anotherapi.example.com alpine ping docker.com
docker service create --name anotherapi-example-com_v1-0001 --label st.tags="backend,development,public,internal,api" --label st.version="1.001" --label st.group=anotherapi.example.com alpine ping docker.com
docker service create --name anotherapi-example-com_v1-0002 --label st.tags="backend,development,public,internal,api" --label st.version="1.002" --label st.group=anotherapi.example.com alpine ping docker.com
```
#### 2 - Run swarm-template
```shell
go get -d -v -t && go build -v && ./swarm-template -template_file="example/template.tmpl" -target_file="example/nginx.conf"
```
#### Results
```shell
# ./swarm-template -template_file="example/template.tmpl" -target_file="example/nginx.conf"
_/zeki/swarm-template
2016/12/20 12:20:47 Starting Swarm Template
2016/12/20 12:20:47 Added : api-example-com_v1-001
2016/12/20 12:20:47 Added : www-example-com
2016/12/20 12:20:47 Added : anotherapi-example-com_v1-0000
2016/12/20 12:20:47 Added : anotherapi-example-com_v1-0001
2016/12/20 12:20:47 Added : anotherapi-example-com_v1-0002
2016/12/20 12:20:47 Added : logs-example-com
2016/12/20 12:20:47 Added : api-example-com_v1-000
2016/12/20 12:20:47 Added : static-example-com
```
##### template file
```
{{ define "main" }}
########################################################################################################################
# List Backend UpStreams
########################################################################################################################
{{ range $service := . }}{{$service_name:=.Name}}{{ range $label := .Labels }}{{ if and ( . | contains "backend") ( . | contains "development") }}
upstream {{$service_name}} {
server {{$service_name}}:9000 weight=100 max_fails=5000 fail_timeout=5;
}{{ end }}{{ end }}{{ end }}
########################################################################################################################
# List External Services
########################################################################################################################
{{$services := .}}{{ range group . }}{{$service_name:=.Name}}{{$domain := index .Labels "st.group"}}{{ range $label := .Labels }}{{ if and ( . | contains "backend") ( . | contains "development") }}
server {
listen 80;
server_name {{$domain}};
..
...
location @rewrite3 {
rewrite ^({{ range keyBy $services $domain}}/v{{index .Labels "st.version"}}|{{end}})/(.*)$ $1/index.php?_url=/$2;
}
{{ range keyBy $services $domain}}{{$version := index .Labels "st.version"}}
location /v{{$version}} {
root /www/http/public/;
try_files $uri $uri/ @rewrite3;
location ~ ^/v{{$version}}(.+\.php)$ {
fastcgi_pass {{$service_name}};
..
...
fastcgi_param VERSION v{{$version}};
}
}{{end}}
}{{ end }}{{end}}{{end}}
########################################################################################################################
# List Internal Setup
########################################################################################################################
server {
listen 80 default_server;
server_name _;
..
...
location @rewrite2 {
rewrite ^({{ range $service := . }}{{$service_name:=.Name}}{{ range $label := .Labels }}{{ if and ( . | contains "development") ( . | contains "backend") ( . | contains "internal") }}{{$service_parse := $service_name | split "_"}}{{range $key, $value := $service_parse}}{{if eq $key 1}}{{$value_v := $value | replaceAll "-" "."}}/{{$value_v}}{{else}}/{{$value}}{{end}}{{end}}|{{end}}{{end}}{{end}})/(.*)$ $1/index.php?_url=/$2;
}
{{ range $service := . }}{{$service_name:=.Name}}{{ range $label := .Labels }}{{ if and ( . | contains "development") ( . | contains "backend") ( . | contains "internal") }}{{$service_parse := $service_name | split "_"}}
location {{range $key, $value := $service_parse}}{{if eq $key 1}}{{$value_v := $value | replaceAll "-" "."}}/{{$value_v}}{{else}}/{{$value}}{{end}}{{end}} {
root /www/http/public/;
try_files $uri $uri/ @rewrite2;
location ~ ^{{$service_parse := $service_name | split "_"}}{{range $key, $value := $service_parse}}{{if eq $key 1}}{{$value_v := $value | replaceAll "-" "."}}/{{$value_v}}{{else}}/{{$value}}{{end}}{{end}}(.+\.php)$ {
fastcgi_pass {{$service_name}};
..
...
fastcgi_param VERSION {{$service_parse := $service_name | split "_"}}{{range $key, $value := $service_parse}}{{if eq $key 1}}{{$value_v := $value | replaceAll "-" "."}}{{$value_v}}{{end}}{{end}};
}
}{{end}}{{end}}{{end}}
}
{{end}}
```
##### generated target file
```
########################################################################################################################
# List Backend UpStreams
########################################################################################################################
upstream anotherapi-example-com_v1-0000 {
server anotherapi-example-com_v1-0000:9000 weight=100 max_fails=5000 fail_timeout=5;
}
upstream api-example-com_v1-001 {
server api-example-com_v1-001:9000 weight=100 max_fails=5000 fail_timeout=5;
}
upstream www-example-com {
server www-example-com:9000 weight=100 max_fails=5000 fail_timeout=5;
}
upstream api-example-com_v1-000 {
server api-example-com_v1-000:9000 weight=100 max_fails=5000 fail_timeout=5;
}
upstream logs-example-com {
server logs-example-com:9000 weight=100 max_fails=5000 fail_timeout=5;
}
upstream anotherapi-example-com_v1-0001 {
server anotherapi-example-com_v1-0001:9000 weight=100 max_fails=5000 fail_timeout=5;
}
upstream anotherapi-example-com_v1-0002 {
server anotherapi-example-com_v1-0002:9000 weight=100 max_fails=5000 fail_timeout=5;
}
########################################################################################################################
# List External Services
########################################################################################################################
server {
listen 80;
server_name anotherapi.example.com;
..
...
location @rewrite3 {
rewrite ^(/v1.000|/v1.001|/v1.002|)/(.*)$ $1/index.php?_url=/$2;
}
location /v1.000 {
root /www/http/public/;
try_files $uri $uri/ @rewrite3;
location ~ ^/v1.000(.+\.php)$ {
fastcgi_pass anotherapi-example-com_v1-0000;
..
...
fastcgi_param VERSION v1.000;
}
}
location /v1.001 {
root /www/http/public/;
try_files $uri $uri/ @rewrite3;
location ~ ^/v1.001(.+\.php)$ {
fastcgi_pass anotherapi-example-com_v1-0000;
..
...
fastcgi_param VERSION v1.001;
}
}
location /v1.002 {
root /www/http/public/;
try_files $uri $uri/ @rewrite3;
location ~ ^/v1.002(.+\.php)$ {
fastcgi_pass anotherapi-example-com_v1-0000;
..
...
fastcgi_param VERSION v1.002;
}
}
}
server {
listen 80;
server_name api.example.com;
..
...
location @rewrite3 {
rewrite ^(/v1.001|/v1.000|)/(.*)$ $1/index.php?_url=/$2;
}
location /v1.001 {
root /www/http/public/;
try_files $uri $uri/ @rewrite3;
location ~ ^/v1.001(.+\.php)$ {
fastcgi_pass api-example-com_v1-001;
..
...
fastcgi_param VERSION v1.001;
}
}
location /v1.000 {
root /www/http/public/;
try_files $uri $uri/ @rewrite3;
location ~ ^/v1.000(.+\.php)$ {
fastcgi_pass api-example-com_v1-001;
..
...
fastcgi_param VERSION v1.000;
}
}
}
server {
listen 80;
server_name www.example.com;
..
...
location @rewrite3 {
rewrite ^(/v1.000|)/(.*)$ $1/index.php?_url=/$2;
}
location /v1.000 {
root /www/http/public/;
try_files $uri $uri/ @rewrite3;
location ~ ^/v1.000(.+\.php)$ {
fastcgi_pass www-example-com;
..
...
fastcgi_param VERSION v1.000;
}
}
}
server {
listen 80;
server_name logs.example.com;
..
...
location @rewrite3 {
rewrite ^(/v1.000|)/(.*)$ $1/index.php?_url=/$2;
}
location /v1.000 {
root /www/http/public/;
try_files $uri $uri/ @rewrite3;
location ~ ^/v1.000(.+\.php)$ {
fastcgi_pass logs-example-com;
..
...
fastcgi_param VERSION v1.000;
}
}
}
########################################################################################################################
# List Internal Setup
########################################################################################################################
server {
listen 80 default_server;
server_name _;
..
...
location @rewrite2 {
rewrite ^(/anotherapi-example-com/v1.0000|/api-example-com/v1.001|/api-example-com/v1.000|/logs-example-com|/anotherapi-example-com/v1.0001|/anotherapi-example-com/v1.0002|)/(.*)$ $1/index.php?_url=/$2;
}
location /anotherapi-example-com/v1.0000 {
root /www/http/public/;
try_files $uri $uri/ @rewrite2;
location ~ ^/anotherapi-example-com/v1.0000(.+\.php)$ {
fastcgi_pass anotherapi-example-com_v1-0000;
..
...
fastcgi_param VERSION v1.0000;
}
}
location /api-example-com/v1.001 {
root /www/http/public/;
try_files $uri $uri/ @rewrite2;
location ~ ^/api-example-com/v1.001(.+\.php)$ {
fastcgi_pass api-example-com_v1-001;
..
...
fastcgi_param VERSION v1.001;
}
}
location /api-example-com/v1.000 {
root /www/http/public/;
try_files $uri $uri/ @rewrite2;
location ~ ^/api-example-com/v1.000(.+\.php)$ {
fastcgi_pass api-example-com_v1-000;
..
...
fastcgi_param VERSION v1.000;
}
}
location /logs-example-com {
root /www/http/public/;
try_files $uri $uri/ @rewrite2;
location ~ ^/logs-example-com(.+\.php)$ {
fastcgi_pass logs-example-com;
..
...
fastcgi_param VERSION ;
}
}
location /anotherapi-example-com/v1.0001 {
root /www/http/public/;
try_files $uri $uri/ @rewrite2;
location ~ ^/anotherapi-example-com/v1.0001(.+\.php)$ {
fastcgi_pass anotherapi-example-com_v1-0001;
..
...
fastcgi_param VERSION v1.0001;
}
}
location /anotherapi-example-com/v1.0002 {
root /www/http/public/;
try_files $uri $uri/ @rewrite2;
location ~ ^/anotherapi-example-com/v1.0002(.+\.php)$ {
fastcgi_pass anotherapi-example-com_v1-0002;
..
...
fastcgi_param VERSION v1.0002;
}
}
}
```
### Templating Language
Swarm Template consumes template files in the [Go Template][] format.
#### Additional Functions
##### `env`
Wrapper for os.Getenv. Retrieves the value of the environment variable named by the key. It returns the value, which will be empty if the variable is not present. Optionally, you can give a default value that will be returned if the key is not present.
```liquid
{{env "HOSTNAME" "127.0.0.1"}}
```
##### `group`
Query Swarm API for all services in the group by "st.group" label. Services are queried using the following syntax:
```liquid
{{ range group . }}
# ...
{{ end}}
```
##### `KeyBy`
Creates a map that groups services by tag
```liquid
{{$services := . }}
{{ range keyBy $services "example_value"}}
# ...
{{end}}
```
##### `contains`
Determines if a needle is within an iterable element.
```liquid
{{ range .Labels }}
{{ if and ( . | contains "backend") ( . | contains "production") }}
# ...
{{ end }}
{{ end }}
```
##### `replaceAll`
Takes the argument as a string and replaces all occurrences of the given string with the given string.
```liquid
{{"foo.bar" | replaceAll "." "_"}}
```
This function can be chained with other functions as well:
```liquid
{{$variable := .Example | replaceAll "-" "."}}
```
##### `split`
Splits the given string on the provided separator:
```liquid
{{"application_version" | split "_"}}
```
Contributing
------------
### Build
```
docker run --rm --name go-build -v "$PWD":"/go/src/swarm-template" -w "/go/src/swarm-template" golang sh -c " go get; go build -v"
```
#### Alpine
```
docker run --rm -v "$PWD":"/go/src/swarm-template" -w "/go/src/swarm-template" golang:alpine sh -c "apk add --update git && go get -v; go build -v" && tar -zcvf swarm-template.tar.gz $PWD/swarm-template
```
If you want to contribute to our project, please follow these guidelines:
1. Fork the repo
2. Choose the correct branch to base your contribution (see details bellow)
3. Implement and test your code
4. Submit a pull request
ToDo
------------
* -cmd options multi command support
Thank You
------------
* [AzMesai](http://azmesai.net/) Group Members