Merge pull request #138 from castai/feat/config-from-file

feat: add ablity to read config from file

README.md

@@ -10,6 +10,30 @@ Visit the [docs](https://docs.cast.ai/docs/getting-started) to connect your clus
 
 The helm chart for the CAST AI Kubernetes agent is published in the [castai/helm-charts](https://github.com/castai/helm-charts) repo.
 
+
+## Reading configuration from file
+
+You can pass configuration to agent via YAML file.
+
+Example file
+```yaml
+api:
+  key: "api key"
+  url: "api.cast.ai"
+```
+or
+
+```yaml
+api.key: "api key"
+api.url: "api.cast.ai"
+```
+
+Shell example
+
+```shell 
+CONFIG_PATH=<PATH_TO_CONFIG> ./castai-agent
+```
+
 ## Contributing
 
 ### Run the agent in your IDE 

internal/config/config.go

@@ -2,6 +2,7 @@ package config
 
 import (
 	"fmt"
+	"os"
 	"strings"
 	"sync"
 	"time"
@@ -150,6 +151,16 @@ func Get() Config {
 
 	cfg = &Config{}
 	bindEnvs(*cfg)
+
+	if cfgFile := os.Getenv("CONFIG_PATH"); cfgFile != "" {
+		fmt.Println("Using config from a file", cfgFile)
+		viper.SetConfigType("yaml")
+		viper.SetConfigFile(cfgFile)
+		if err := viper.ReadInConfig(); err != nil {
+			panic(fmt.Errorf("reading default config: %v", err))
+		}
+	}
+
 	if err := viper.Unmarshal(&cfg); err != nil {
 		panic(fmt.Errorf("parsing configuration: %v", err))
 	}