Implement input

examples/cmd-proxy/assets/summon.config.yaml

@@ -104,3 +104,11 @@ exec:
       cmd: [docker, run, -ti, -v, '{{ env "PWD"}}:/workdir', -w, /workdir, alpine]
       args: [echo]
       help: use alpine to echo a string
+
+    prompt:
+      prompts: '{{ prompt "slotA" "What is your name" "David" }}'
+      cmd: [bash, -c]
+      args:
+        - |
+          echo hello {{ promptValue "slotA" }}! \
+          How should I continue {{ prompt "continue" "Select One" (list "A" "B" "C") }}

go.mod

@@ -1,16 +1,17 @@
 module github.com/davidovich/summon
 
-go 1.21
+go 1.23
 
 require (
 	github.com/DiSiqueira/GoTree v1.0.1-0.20190529205929-3e23dcd4532b
 	github.com/Masterminds/sprig/v3 v3.2.3
+	github.com/cqroot/prompt v0.9.4
 	github.com/google/go-cmp v0.6.0
 	github.com/lithammer/dedent v1.1.0
 	github.com/spf13/afero v1.11.0
 	github.com/spf13/cobra v1.8.0
 	github.com/spf13/pflag v1.0.5
-	github.com/stretchr/testify v1.8.4
+	github.com/stretchr/testify v1.9.0
 	golang.org/x/exp v0.0.0-20231226003508-02704c960a9b
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -19,16 +20,36 @@ require (
 	github.com/Masterminds/goutils v1.1.1 // indirect
 	github.com/Masterminds/semver/v3 v3.2.1 // indirect
 	github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be
+	github.com/atotto/clipboard v0.1.4 // indirect
+	github.com/aymanbagabas/go-osc52/v2 v2.0.1 // indirect
+	github.com/charmbracelet/bubbles v0.16.1 // indirect
+	github.com/charmbracelet/bubbletea v0.24.2 // indirect
+	github.com/charmbracelet/lipgloss v0.11.0 // indirect
+	github.com/charmbracelet/x/ansi v0.1.1 // indirect
+	github.com/containerd/console v1.0.4-0.20230313162750-1ae8d489ac81 // indirect
+	github.com/cqroot/multichoose v0.1.1 // indirect
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/google/uuid v1.5.0 // indirect
 	github.com/huandu/xstrings v1.4.0 // indirect
 	github.com/imdario/mergo v0.3.16 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
+	github.com/lucasb-eyer/go-colorful v1.2.0 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/mattn/go-localereader v0.0.1 // indirect
+	github.com/mattn/go-runewidth v0.0.15 // indirect
 	github.com/mitchellh/copystructure v1.2.0 // indirect
 	github.com/mitchellh/reflectwalk v1.0.2 // indirect
+	github.com/muesli/ansi v0.0.0-20211018074035-2e021307bc4b // indirect
+	github.com/muesli/cancelreader v0.2.2 // indirect
+	github.com/muesli/reflow v0.3.0 // indirect
+	github.com/muesli/termenv v0.15.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/rivo/uniseg v0.4.7 // indirect
 	github.com/shopspring/decimal v1.3.1 // indirect
 	github.com/spf13/cast v1.6.0 // indirect
 	golang.org/x/crypto v0.17.0 // indirect
+	golang.org/x/sync v0.5.0 // indirect
+	golang.org/x/sys v0.19.0 // indirect
+	golang.org/x/term v0.15.0 // indirect
 	golang.org/x/text v0.14.0 // indirect
 )

go.sum

@@ -9,7 +9,25 @@ github.com/Masterminds/sprig/v3 v3.2.3 h1:eL2fZNezLomi0uOLqjQoN6BfsDD+fyLtgbJMAj
 github.com/Masterminds/sprig/v3 v3.2.3/go.mod h1:rXcFaZ2zZbLRJv/xSysmlgIM1u11eBaRMhvYXJNkGuM=
 github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be h1:9AeTilPcZAjCFIImctFaOjnTIavg87rW78vTPkQqLI8=
 github.com/anmitsu/go-shlex v0.0.0-20200514113438-38f4b401e2be/go.mod h1:ySMOLuWl6zY27l47sB3qLNK6tF2fkHG55UZxx8oIVo4=
+github.com/atotto/clipboard v0.1.4 h1:EH0zSVneZPSuFR11BlR9YppQTVDbh5+16AmcJi4g1z4=
+github.com/atotto/clipboard v0.1.4/go.mod h1:ZY9tmq7sm5xIbd9bOK4onWV4S6X0u6GY7Vn0Yu86PYI=
+github.com/aymanbagabas/go-osc52/v2 v2.0.1 h1:HwpRHbFMcZLEVr42D4p7XBqjyuxQH5SMiErDT4WkJ2k=
+github.com/aymanbagabas/go-osc52/v2 v2.0.1/go.mod h1:uYgXzlJ7ZpABp8OJ+exZzJJhRNQ2ASbcXHWsFqH8hp8=
+github.com/charmbracelet/bubbles v0.16.1 h1:6uzpAAaT9ZqKssntbvZMlksWHruQLNxg49H5WdeuYSY=
+github.com/charmbracelet/bubbles v0.16.1/go.mod h1:2QCp9LFlEsBQMvIYERr7Ww2H2bA7xen1idUDIzm/+Xc=
+github.com/charmbracelet/bubbletea v0.24.2 h1:uaQIKx9Ai6Gdh5zpTbGiWpytMU+CfsPp06RaW2cx/SY=
+github.com/charmbracelet/bubbletea v0.24.2/go.mod h1:XdrNrV4J8GiyshTtx3DNuYkR1FDaJmO3l2nejekbsgg=
+github.com/charmbracelet/lipgloss v0.11.0 h1:UoAcbQ6Qml8hDwSWs0Y1cB5TEQuZkDPH/ZqwWWYTG4g=
+github.com/charmbracelet/lipgloss v0.11.0/go.mod h1:1UdRTH9gYgpcdNN5oBtjbu/IzNKtzVtb7sqN1t9LNn8=
+github.com/charmbracelet/x/ansi v0.1.1 h1:CGAduulr6egay/YVbGc8Hsu8deMg1xZ/bkaXTPi1JDk=
+github.com/charmbracelet/x/ansi v0.1.1/go.mod h1:dk73KoMTT5AX5BsX0KrqhsTqAnhZZoCBjs7dGWp4Ktw=
+github.com/containerd/console v1.0.4-0.20230313162750-1ae8d489ac81 h1:q2hJAaP1k2wIvVRd/hEHD7lacgqrCPS+k8g1MndzfWY=
+github.com/containerd/console v1.0.4-0.20230313162750-1ae8d489ac81/go.mod h1:YynlIjWYF8myEu6sdkwKIvGQq+cOckRm6So2avqoYAk=
 github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/cqroot/multichoose v0.1.1 h1:diGuKYKea9ePOTwUyUDor9zKRqKFWXGkYGqUa9+firU=
+github.com/cqroot/multichoose v0.1.1/go.mod h1:BJzIGqbQZNADPDuA3IzhmTMpRc2F3fZKysMRYP+Ydw8=
+github.com/cqroot/prompt v0.9.4 h1:uFRlhXuOP3CSD+Pii0Z8VJhgXpavSloFf7/KAERwjz8=
+github.com/cqroot/prompt v0.9.4/go.mod h1:6BVZiEv7XkW1K64y1k2wdzToDwspL3n/RkUIyPjQ808=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
@@ -34,14 +52,35 @@ github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/lithammer/dedent v1.1.0 h1:VNzHMVCBNG1j0fh3OrsFRkVUwStdDArbgBWoPAffktY=
 github.com/lithammer/dedent v1.1.0/go.mod h1:jrXYCQtgg0nJiN+StA2KgR7w6CiQNv9Fd/Z9BP0jIOc=
+github.com/lucasb-eyer/go-colorful v1.2.0 h1:1nnpGOrhyZZuNyfu1QjKiUICQ74+3FNCN69Aj6K7nkY=
+github.com/lucasb-eyer/go-colorful v1.2.0/go.mod h1:R4dSotOR9KMtayYi1e77YzuveK+i7ruzyGqttikkLy0=
+github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
+github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/mattn/go-localereader v0.0.1 h1:ygSAOl7ZXTx4RdPYinUpg6W99U8jWvWi9Ye2JC/oIi4=
+github.com/mattn/go-localereader v0.0.1/go.mod h1:8fBrzywKY7BI3czFoHkuzRoWE9C+EiG4R1k4Cjx5p88=
+github.com/mattn/go-runewidth v0.0.12/go.mod h1:RAqKPSqVFrSLVXbA8x7dzmKdmGzieGRCM46jaSJTDAk=
+github.com/mattn/go-runewidth v0.0.15 h1:UNAjwbU9l54TA3KzvqLGxwWjHmMgBUVhBiTjelZgg3U=
+github.com/mattn/go-runewidth v0.0.15/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
 github.com/mitchellh/copystructure v1.0.0/go.mod h1:SNtv71yrdKgLRyLFxmLdkAbkKEFWgYaq1OVrnRcwhnw=
 github.com/mitchellh/copystructure v1.2.0 h1:vpKXTN4ewci03Vljg/q9QvCGUDttBOGBIa15WveJJGw=
 github.com/mitchellh/copystructure v1.2.0/go.mod h1:qLl+cE2AmVv+CoeAwDPye/v+N2HKCj9FbZEVFJRxO9s=
 github.com/mitchellh/reflectwalk v1.0.0/go.mod h1:mSTlrgnPZtwu0c4WaC2kGObEpuNDbx0jmZXqmk4esnw=
 github.com/mitchellh/reflectwalk v1.0.2 h1:G2LzWKi524PWgd3mLHV8Y5k7s6XUvT0Gef6zxSIeXaQ=
 github.com/mitchellh/reflectwalk v1.0.2/go.mod h1:mSTlrgnPZtwu0c4WaC2kGObEpuNDbx0jmZXqmk4esnw=
+github.com/muesli/ansi v0.0.0-20211018074035-2e021307bc4b h1:1XF24mVaiu7u+CFywTdcDo2ie1pzzhwjt6RHqzpMU34=
+github.com/muesli/ansi v0.0.0-20211018074035-2e021307bc4b/go.mod h1:fQuZ0gauxyBcmsdE3ZT4NasjaRdxmbCS0jRHsrWu3Ho=
+github.com/muesli/cancelreader v0.2.2 h1:3I4Kt4BQjOR54NavqnDogx/MIoWBFa0StPA8ELUXHmA=
+github.com/muesli/cancelreader v0.2.2/go.mod h1:3XuTXfFS2VjM+HTLZY9Ak0l6eUKfijIfMUZ4EgX0QYo=
+github.com/muesli/reflow v0.3.0 h1:IFsN6K9NfGtjeggFP+68I4chLZV2yIKsXJFNZ+eWh6s=
+github.com/muesli/reflow v0.3.0/go.mod h1:pbwTDkVPibjO2kyvBQRBxTWEEGDGq0FlB1BIKtnHY/8=
+github.com/muesli/termenv v0.15.2 h1:GohcuySI0QmI3wN8Ok9PtKGkgkFIk7y6Vpb5PvrY+Wo=
+github.com/muesli/termenv v0.15.2/go.mod h1:Epx+iuz8sNs7mNKhxzH4fWXGNpZwUaJKRS1noLXviQ8=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
+github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=
+github.com/rivo/uniseg v0.4.7/go.mod h1:FN3SvrM+Zdj16jyLfmOkMNblXMcoc8DfTHruCPUcx88=
 github.com/rogpeppe/go-internal v1.9.0 h1:73kH8U+JUqXU8lRuOHeVHaa/SZPifC7BkcraZVejAe8=
 github.com/rogpeppe/go-internal v1.9.0/go.mod h1:WtVeX8xhTBvf0smdhujwtBcq4Qrzq/fJaraNFVN+nFs=
 github.com/russross/blackfriday/v2 v2.1.0/go.mod h1:+Rmxgy9KzJVeS9/2gXHxylqXiyQDYRxCVz55jmeOWTM=
@@ -60,8 +99,8 @@ github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
-github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
-github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210921155107-089bfa567519/go.mod h1:GvvjBRRGRdwPK5ydBHafDWAxML/pGHZbMvKqRZ5+Abc=
@@ -77,15 +116,23 @@ golang.org/x/net v0.0.0-20220722155237-a158d28d115b/go.mod h1:XRhObCWvk6IyKnWLug
 golang.org/x/net v0.2.0/go.mod h1:KqCZLdyyvdV855qA2rE3GC2aiw5xGR5TEjj8smXukLY=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20220722155255-886fb9371eb4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.5.0 h1:60k92dhOjHxJkrqnwsfl8KuaHbn/5dl0lUPUklKo3qE=
+golang.org/x/sync v0.5.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20201119102817-f84b799fce68/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20210615035016-665e8c7367d1/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.0.0-20220722155257-8c9f86f7a55f/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.2.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.19.0 h1:q5f1RH2jigJ1MoAWp2KTp3gm5zAGFUTarQZ5U386+4o=
+golang.org/x/sys v0.19.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
 golang.org/x/term v0.0.0-20201126162022-7de9c90e9dd1/go.mod h1:bj7SfCRtBDWHUb9snDiAeCFNEtKQo2Wmx5Cou7ajbmo=
 golang.org/x/term v0.0.0-20210927222741-03fcf44c2211/go.mod h1:jbD1KX2456YbFQfuXm/mYQcufACuNUgVhRMnK/tPxf8=
 golang.org/x/term v0.2.0/go.mod h1:TVmDHMZPmdnySmBfhjOoOdhjzdE1h4u1VwSiw2l1Nuc=
+golang.org/x/term v0.15.0 h1:y/Oo/a/q3IXu26lQgl04j/gjuBDOBlx7X6Om1j2CPW4=
+golang.org/x/term v0.15.0/go.mod h1:BDl952bC7+uMoWR75FIrCDx79TPU9oHkTZ9yRbYOrX0=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.3/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
 golang.org/x/text v0.3.7/go.mod h1:u+2+/6zg+i71rQMx5EYifcz6MCKuco9NR6JIITiCfzQ=

main.go

@@ -9,13 +9,13 @@ code snippets distributed in many repos (like general makefile recipes), leverag
 management. It also allows configuring a standard set of tools that a dev team can readily
 invoke by name.
 
-Basics
+# Basics
 
 This library needs a command entrypoint in a data repository. See https://github.com/davidovich/summon-example-assets.
 It can be bootstrapped in an empty directory by using:
 
-  cd [empty data repo dir]
-  go run github.com/davidovich/summon/scaffold@latest init [module name]
+	cd [empty data repo dir]
+	go run github.com/davidovich/summon/scaffold@latest init [module name]
 */
 package summon
 
@@ -49,7 +49,7 @@ func Main(args []string, fs embed.FS, opts ...option) int {
 		return 1
 	}
 
-	c := make(chan os.Signal)
+	c := make(chan os.Signal, 1)
 	signal.Notify(c, os.Interrupt, syscall.SIGTERM)
 	go func() {
 		for range c {

pkg/config/config.go

@@ -52,6 +52,8 @@ type ArgSliceSpec []interface{}
 // Its Flags can be a one line string flag or a FlagSpec
 type CmdDesc struct {
 	Cmd ArgSliceSpec `yaml:"cmd"`
+	// Prompts are used to prompt the user with values. They can be templated.
+	Prompts string `yaml:"prompts"`
 	// Args contain the args that get appended to the ExecEnvironment
 	Args ArgSliceSpec `yaml:"args"`
 	// SubCmd describes a sub-command of current command
@@ -98,11 +100,21 @@ func (e *FlagDesc) UnmarshalYAML(value *yaml.Node) error {
 	switch value.Kind {
 	case yaml.ScalarNode:
 		var args string
-		value.Decode(&args)
+		err := value.Decode(&args)
+		if err != nil {
+			return &yaml.TypeError{
+				Errors: []string{fmt.Sprintf("could not decode flag: %s", err)},
+			}
+		}
 		e.Value = args
 	case yaml.MappingNode:
 		flag := FlagSpec{}
-		value.Decode(&flag)
+		err := value.Decode(&flag)
+		if err != nil {
+			return &yaml.TypeError{
+				Errors: []string{fmt.Sprintf("could not decode flag as mapping: %s", err)},
+			}
+		}
 		e.Value = flag
 	default:
 		return &yaml.TypeError{

pkg/summon/driver.go

@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"os"
 	"path"
 	"text/template"
@@ -35,6 +34,8 @@ type Driver struct {
 	configRead    bool
 	flagsToRender []*flagValue
 	cmdToSpec     map[*cobra.Command]*commandSpec
+	prompts       map[string]string
+	prompter      Prompter
 }
 
 // New creates the Driver.
@@ -43,6 +44,8 @@ func New(filesystem fs.FS, opts ...Option) (*Driver, error) {
 		fs:          filesystem,
 		execCommand: command.New,
 		cmdToSpec:   map[*cobra.Command]*commandSpec{},
+		prompts:     map[string]string{},
+		prompter:    &Prompt{},
 	}
 
 	err := fs.WalkDir(d.fs, ".", func(path string, de fs.DirEntry, err error) error {
@@ -131,6 +134,11 @@ func (d *Driver) Configure(opts ...Option) error {
 		d.opts.data = map[string]interface{}{}
 	}
 
+	// override prompter
+	if d.opts.prompter != nil {
+		d.prompter = d.opts.prompter
+	}
+
 	d.opts.data["osArgs"] = os.Args
 
 	return nil
@@ -156,9 +164,9 @@ func (jv *jsonValue) Set(s string) error {
 		var j []byte
 		var err error
 		if s == "-" {
-			j, err = ioutil.ReadAll(jv.cmd.InOrStdin())
+			j, err = io.ReadAll(jv.cmd.InOrStdin())
 		} else {
-			j, err = ioutil.ReadFile(s)
+			j, err = os.ReadFile(s)
 		}
 		if err != nil {
 			return err

pkg/summon/interface.go

@@ -36,3 +36,10 @@ type ConfigurableLister interface {
 type Lister interface {
 	List(opts ...Option) ([]string, error)
 }
+
+// Prompter allows prompting the user.
+type Prompter interface {
+	NewPrompt(userPrompt string)
+	Choose(choices []string) (string, error)
+	Input(defaultVal string) (string, error)
+}

pkg/summon/options.go

@@ -22,7 +22,7 @@ type options struct {
 	all bool
 	// where the summoned file will land or stdout if "-"
 	destination string
-	// single file to instanciate
+	// single file to instantiate
 	filename string
 	// show tree of files
 	tree bool
@@ -50,6 +50,8 @@ type options struct {
 	dryrun bool
 	// execCommand overrides the command used to run external processes
 	execCommand command.ExecCommandFn
+	//prompter
+	prompter Prompter
 }
 
 type helpInfo struct {
@@ -188,3 +190,11 @@ func (o *options) DefaultsFrom(conf config.Config) {
 		o.destination = conf.OutputDir
 	}
 }
+
+// WithPrompter configures the prompter. This is mostly used in testing.
+func WithPrompter(p Prompter) Option {
+	return func(opts *options) error {
+		opts.prompter = p
+		return nil
+	}
+}

pkg/summon/run.go

@@ -20,6 +20,8 @@ import (
 type commandSpec struct {
 	// command is the caller environment (docker, bash, python)
 	command config.ArgSliceSpec
+	// Inputs are used to prompt the user with values. They can be templated.
+	prompts string
 	// args is the command and args that get appended to the ExecEnvironment
 	args config.ArgSliceSpec
 	// subCmd sub-command of current command
@@ -80,6 +82,11 @@ func (d *Driver) buildCmdArgs() ([]string, error) {
 		return nil, fmt.Errorf("could not find exec handle reference '%s' in config %s", ref, config.ConfigFileName)
 	}
 
+	_, err := d.renderTemplate(cmdSpec.prompts)
+	if err != nil {
+		return nil, fmt.Errorf("could not get all prompts for exec handle '%s' in config %s, error: %s", ref, config.ConfigFileName, err)
+	}
+
 	execEnv, err := d.RenderArgs(FlattenStrings(cmdSpec.command)...)
 	if err != nil {
 		return nil, err
@@ -144,18 +151,17 @@ func (d *Driver) buildCmdArgs() ([]string, error) {
 func (d *Driver) getCmdSpec() (*commandSpec, string) {
 	var cmdSpec *commandSpec
 	var ref string
-	if d.opts.cobraCmd != nil {
-		cmdSpec = d.cmdToSpec[d.opts.cobraCmd]
-		ref = d.opts.cobraCmd.Name()
-	} else {
-
+	if d.opts.cobraCmd == nil {
 		for cmd, spec := range d.cmdToSpec {
 			if cmd.Name() == d.opts.ref {
 				cmdSpec = spec
 				ref = d.opts.ref
 				break
 			}
 		}
+	} else {
+		cmdSpec = d.cmdToSpec[d.opts.cobraCmd]
+		ref = d.opts.cobraCmd.Name()
 	}
 	return cmdSpec, ref
 }
@@ -216,6 +222,7 @@ func normalizeExecDesc(argsDesc interface{}) (*commandSpec, error) {
 	case config.CmdDesc:
 		c.command = descType.Cmd
 		c.args = descType.Args
+		c.prompts = descType.Prompts
 		c.help = descType.Help
 		c.completion = descType.Completion
 		c.hidden = descType.Hidden
@@ -229,7 +236,7 @@ func normalizeExecDesc(argsDesc interface{}) (*commandSpec, error) {
 				if err != nil {
 					return nil, err
 				}
-				// inherit command if not set explicitely
+				// inherit command if not set explicitly
 				if subCmd.command == nil {
 					subCmd.command = c.command
 				}