https://github.com/sgreben/http-subst-server
tiny static file server, with dead simple templates (just $VARIABLES). single binary, no dependencies. linux, osx, windows. #golang
https://github.com/sgreben/http-subst-server
binary environment-variables golang http server subst
Last synced: 10 months ago
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tiny static file server, with dead simple templates (just $VARIABLES). single binary, no dependencies. linux, osx, windows. #golang
- Host: GitHub
- URL: https://github.com/sgreben/http-subst-server
- Owner: sgreben
- License: mit
- Created: 2018-12-16T10:20:57.000Z (about 7 years ago)
- Default Branch: master
- Last Pushed: 2018-12-17T20:00:33.000Z (about 7 years ago)
- Last Synced: 2025-02-07T14:39:33.988Z (about 1 year ago)
- Topics: binary, environment-variables, golang, http, server, subst
- Language: Go
- Homepage:
- Size: 50.8 KB
- Stars: 1
- Watchers: 3
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# http-subst-server
`http-subst-server` is a minimal HTTP server that serves files and renders templates with `$VARIABLES` in them.
A mash-up of [http-file-server](https://github.com/sgreben/http-file-server) and [subst](https://github.com/sgreben/subst).
## Contents
- [Contents](#contents)
- [Get it](#get-it)
- [Using `go get`](#using-go-get)
- [Pre-built binary](#pre-built-binary)
- [Examples](#examples)
- [Variables from command-line options](#variables-from-command-line-options)
- [Variables from the environment](#variables-from-the-environment)
- [Variables and routes from the environment](#variables-and-routes-from-the-environment)
- [Variables from files](#variables-from-files)
- [Variables from standard input](#variables-from-standard-input)
- [Usage](#usage)
## Get it
### Using `go get`
```sh
go get -u github.com/sgreben/http-subst-server
```
### Pre-built binary
[Download a binary](https://github.com/sgreben/http-subst-server/releases/latest) from the releases page or from the shell:
```sh
# Linux
curl -L https://github.com/sgreben/http-subst-server/releases/download/1.2.9/http-subst-server_1.2.9_linux_x86_64.tar.gz | tar xz
# OS X
curl -L https://github.com/sgreben/http-subst-server/releases/download/1.2.9/http-subst-server_1.2.9_osx_x86_64.tar.gz | tar xz
# Windows
curl -LO https://github.com/sgreben/http-subst-server/releases/download/1.2.9/http-subst-server_1.2.9_windows_x86_64.zip
unzip http-subst-server_1.2.9_windows_x86_64.zip
```
## Examples
The CLI has the following general syntax:
```text
http-subst-server [OPTIONS] [[ROUTE=]PATH...]
```
Template variables can be set via [command-line options](#variables-from-command-line-options), [environment variables](#variables-from-environment), [files](#variables-from-files), and [standard input](#variables-from-standard-input).
### Variables from command-line options
```sh
$ cat example/index.html
$GREETING $SUBJECT
```
```sh
$ http-subst-server -v GREETING=hello -v SUBJECT=world /=example
2018/12/16 09:49:09 serving "./example" on "/"
2018/12/16 09:49:09 http-subst-server listening on ":8080"
```
```sh
$ curl localhost:8080
hello world
```
### Variables from the environment
Environment variables with a name prefixed with `SUBST_VAR_` (or a custom prefix set via `-var-prefix`) can be used in the templates. The prefix is stripped from the variable name, so e.g. `$SUBST_VAR_hello` is `$hello` in the templates.
```sh
$ cat example/index.html
$GREETING $SUBJECT
```
```sh
$ export SUBST_VAR_GREETING=hello
$ export SUBST_VAR_SUBJECT=world
$ http-subst-server /=example
2018/12/16 09:49:09 serving "./example" on "/"
2018/12/16 09:49:09 http-subst-server listening on ":8080"
```
```sh
$ curl localhost:8080
hello world
```
Environment variables can also be injected by using the shorthand `-v NAME` (short for `-variable NAME`) instead of `-v NAME=VALUE`. When `=VALUE` is left off, `http-subst-server` sets `NAME` to the value of `$NAME` in the current environment:
```
$ export GREETING=hello
$ export SUBJECT=world
$ http-subst-server -v GREETING -v SUBJECT /=example
2018/12/16 09:49:09 serving "./example" on "/"
2018/12/16 09:49:09 http-subst-server listening on ":8080"
```
### Variables and routes from the environment
The values of environment variables with names prefixed `SUBST_ROUTE_` (or a custom prefix set via `-route-prefix`) are used as routes. Apart from the name prefix, only the value of the environment variable is relevant.
```sh
$ cat example/index.html
$GREETING $SUBJECT
```
```sh
$ export SUBST_VAR_GREETING=hello
$ export SUBST_VAR_SUBJECT=world
$ export SUBST_ROUTE_1=/=example
$ export SUBST_ROUTE_2=/abc=/tmp
$ http-subst-server
2018/12/16 09:49:09 serving "./example" on "/"
2018/12/16 09:49:09 serving "/tmp" on "/abc/"
2018/12/16 09:49:09 http-subst-server listening on ":8080"
```
```sh
$ curl localhost:8080
hello world
```
### Variables from files
You may specify files containing variable definitions `NAME[=VALUE]` (same syntax as `-variable`/`-v`, one per line) using `-variable-file`/`-f`.
Changes to the definitions in these files will be picked up without having to restart the server.
```sh
$ cat example/index.html
$GREETING $SUBJECT
```
```sh
$ http-subst-server -f variables.env /=example
2018/12/16 09:49:09 serving "./example" on "/"
2018/12/16 09:49:09 http-subst-server listening on ":8080"
```
```sh
$ curl localhost:8080
$GREETING $SUBJECT
```
```sh
$ echo GREETING=hello > variables.env
$ cat variables.env
GREETING=hello
```
```sh
$ curl localhost:8080
hello $SUBJECT
```
```sh
$ echo SUBJECT=world >> variables.env
$ cat variables.env
GREETING=hello
SUBJECT=world
```
```sh
$ curl localhost:8080
hello world
```
### Variables from standard input
If the `-variables-from-stdin`/`-i` flag is given, variable definitions `NAME[=VALUE]` (same syntax as `-variable`/`-v`, one per line) are continuously streamed from standard input (until it is closed). New definitions are available to templates immediately.
```sh
$ cat example/index.html
$GREETING $SUBJECT
```
```sh
$ http-subst-server -i /=example
2018/12/16 09:49:09 serving "./example" on "/"
2018/12/16 09:49:09 http-subst-server listening on ":8080"
018/12/16 21:28:17 reading variable definitions NAME[=VALUE] from stdin
GREETING=foo
SUBJECT=bar
```
```sh
$ curl localhost:8080
foo bar
```
## Usage
```text
http-subst-server [OPTIONS] [[ROUTE=]PATH...]
```
```text
Usage of http-subst-server:
-a string
(alias for -addr) (default ":8080")
-addr string
address to listen on (environment variable "ADDR") (default ":8080")
-escape string
set the escape string - a '$' preceded by this string is not treated as a variable (default "\\")
-f value
(alias for -variable-file)
-i (alias for -variables-from-stdin)
-o string
(alias for -output)
-output string
write the variable mapping to this file whenever it changes
-p int
(alias for -port)
-port int
port to listen on (overrides -addr port) (environment variable "PORT")
-q (alias for -quiet)
-quiet
disable all log output (environment variable "QUIET")
-r value
(alias for -route)
-route value
a route definition ROUTE=PATH (ROUTE defaults to basename of PATH if omitted)
-route-prefix string
use values of environment variables with this prefix as routes (default "SUBST_ROUTE_")
-template-suffix string
replace $variables in files with this suffix (default ".html")
-undefined value
handling of undefined $variables, one of [ignore empty error] (default ignore) (default ignore)
-v value
(alias for -variable)
-var-prefix string
use environment variables with this prefix in templates (default "SUBST_VAR_")
-variable value
a variable definition NAME[=VALUE] (if the value is omitted, the value of the environment variable with the given name is used)
-variable-file value
a file consisting of lines with one variable definition NAME[=VALUE] per line
-variable-file-reload duration
reload interval for variable files (default 1s)
-variables-from-stdin
read lines with variable definitions NAME[=VALUE] from stdin
```