A string render with version control.

Sometimes, we store some text file at server, like nginx, e.g.: shell script, python and so on, then we will do something like: curl www.gogap.cn/xxx.sh | sh for install or run something, but we want it can be replaced by some values that we told the server, it was usefull for storage shell script and run mutil server, we could pass the serverName, branch, commitID and just what you want to replace with.

And also we need support version control for string, you cloud tell string keeper which revision you want to render, you just need to pass branch name or commit id to revision field.

We could do this by golang tmplate, the client side post the file name and key-values to server, the server will build by golang template then replace the values to the raw text stirng

Do some preper

create text file

create file: namespace/bucket/dir1/dir2/abc.sh in public dir

content of namespace/bucket/dir1/dir2/abc.sh

you can use any name with namespace and bucket in real world

#!/bin/bash
echo hello
echo {{.hello}}

configure the conf/string_keeper.conf

{
    "http": {
        "address": ":8080",
        "cors": {
            "allow_origins": ["http://*.gogap.cn"],
            "allow_methods": ["POST"],
            "allow_headers": ["Origin"],
            "expose_headers": ["Content-Length"],
            "allow_cerdentials": false
        }
    },
    "acl": {
        "ip_acl_enabled": true,
        "ip_white_list": ["127.0.0.1"],
        "auth_enabled": true,
        "basic_auth": {
            "namespace/bucket": "token"
        }
    }
}

we have ip white list and bucket auth, it was safe for only deply script

start string_keeper

$ go build
$ ./string_keeper

The post data like following:

{
    "namespace": "namespace",
    "bucket": "bucket",
    "revision": "",
    "file": "dir1/dir2/abc.sh",
    "envs": {
        "hello": "world"
    },
    "raw_data": false
}

envs is an key-value style, the key is in the template file like {{.hello}}, and it will use go template and replace the world with it.

if raw_data is true, we will get the raw template, not replaced with envs values.

if dir1 is git dir, then you could input revision info to pick file with any version, e.g.: master develop HEAD or commit id

Take a look with curl

$ curl -X POST --basic -u "namespace/bucket:token" -d '{
"namespace":"namespace",
"bucket":"bucket",
"file":"dir1/dir2/abc.sh",
"envs": {"hello":"world"},
"raw_data":false
}' http://127.0.0.1:8080/

we got this:

#!/bin/bash
echo hello
echo world

change the "raw_data" to false, we got this:

#!/bin/bash
echo hello
echo {{.hello}}

We are using gitlab-ci for continuous integration, and we have about 20 components project, and these project had same test and deploy shell script, storage the script at string_keeper, and put following bash script in gitlab-ci deploy jobs.

gitlab-ci deploy job

curl -X POST --basic -u "ci-scripts-development/components:password" -d '{
    "namespace": "ci-scripts-development",
    "bucket": "components",
    "revision": "develop",
    "file": "common/build_and_run.sh",
    "raw_data":false,
    "envs":{
           "gopath":"/gopath",
           "launchboard_path":"/launchboard/components",
           "package":"git.xxx.com/components/sms",
           "component_name":"sms",
           "compose_name":"sms",
           "brunch":"develop" 
    }
}' https://string-keeper.xxx.com | sh

deploy script

File:ci-scripts-development/components/common/build_and_run.sh

#/bin/bash
cd  {{.gopath}}/src/{{.package}}
git checkout {{.brunch}}

cd {{.launchboard_path}}/{{.component_name}}
make
cd ..
docker-compose build {{.compose_name}}
docker-compose stop {{.compose_name}}
docker-compose rm -f {{.compose_name}}
docker-compose up -d {{.compose_name}}
pid=$(docker inspect --format='{{"{{.State.Pid}}"}}' components_{{.compose_name}}_1)
if [ $pid = "0"  ]; then
    exit  3
fi