Add ability to set environment variables via CLI

cmd_env.go

@@ -10,7 +10,7 @@ var commandEnv = cli.Command{
 		var err error
 
 		proc := NewProcess("env")
-		proc.AppendConfigSource(configSourceFromContext(c))
+		proc.AppendConfigSource(configSourcesFromContext(c)...)
 
 		err = proc.Start()
 		if err != nil {

cmd_run.go

@@ -12,7 +12,7 @@ var commandRun = cli.Command{
 		}
 
 		proc := NewProcess(c.Args().First(), c.Args().Tail()...)
-		proc.AppendConfigSource(configSourceFromContext(c))
+		proc.AppendConfigSource(configSourcesFromContext(c)...)
 
 		err = proc.Start()
 		if err != nil {

cmd_start.go

@@ -32,7 +32,7 @@ var commandStart = cli.Command{
 		}
 
 		proc := NewProcess(command[0], command[1:]...)
-		proc.AppendConfigSource(configSourceFromContext(c))
+		proc.AppendConfigSource(configSourcesFromContext(c)...)
 
 		err = proc.Start()
 		if err != nil {

config.go

@@ -12,12 +12,16 @@ type ConfigSource interface {
 
 const metadataConfigSourceKey = "configSource"
 
-func setConfigSource(c *cli.Context, src ConfigSource) {
-	c.App.Metadata[metadataConfigSourceKey] = src
+func appendConfigSource(c *cli.Context, src ConfigSource) {
+	m, ok := c.App.Metadata[metadataConfigSourceKey].([]ConfigSource)
+	if !ok {
+		m = []ConfigSource{}
+	}
+	c.App.Metadata[metadataConfigSourceKey] = append(m, src)
 }
 
-func configSourceFromContext(c *cli.Context) ConfigSource {
-	if src, ok := c.App.Metadata[metadataConfigSourceKey].(ConfigSource); ok {
+func configSourcesFromContext(c *cli.Context) []ConfigSource {
+	if src, ok := c.App.Metadata[metadataConfigSourceKey].([]ConfigSource); ok {
 		return src
 	}
 	return nil

config_stringslice.go

@@ -0,0 +1,19 @@
+package main
+
+import "context"
+
+type StringSliceConfigSource struct {
+	Config []string
+}
+
+func NewStringSliceConfigSource(config []string) *StringSliceConfigSource {
+	src := &StringSliceConfigSource{
+		Config: make([]string, len(config)),
+	}
+	copy(src.Config, config)
+	return src
+}
+
+func (src *StringSliceConfigSource) List(ctx context.Context) ([]string, error) {
+	return src.Config, nil
+}

main.go

@@ -19,8 +19,13 @@ func main() {
 			Name:   "config-table",
 			EnvVar: "SIDEKICK_CONFIG_TABLE",
 		},
+		cli.StringSliceFlag{
+			Name:  "env, e",
+			Usage: "set environment variables",
+		},
 	}
 	app.Before = func(c *cli.Context) error {
+		// TODO: support multiple config sources
 		var configSource ConfigSource
 		switch c.String("config-source") {
 		case "dynamodb":
@@ -32,7 +37,12 @@ func main() {
 			return cli.NewExitError("couldn't find that config source type", 2)
 		}
 
-		setConfigSource(c, configSource)
+		appendConfigSource(c, configSource)
+
+		envs := c.StringSlice("env")
+		if len(envs) > 0 {
+			appendConfigSource(c, NewStringSliceConfigSource(envs))
+		}
 
 		return nil
 	}

process.go

@@ -23,8 +23,8 @@ func NewProcess(name string, arg ...string) *Process {
 	return p
 }
 
-func (p *Process) AppendConfigSource(src ConfigSource) {
-	p.configSources = append(p.configSources, src)
+func (p *Process) AppendConfigSource(sources ...ConfigSource) {
+	p.configSources = append(p.configSources, sources...)
 }
 
 func (p *Process) resetAndInstallEnv() error {