Function Specification
function.json file in the function directory is optional. tc infers the language and build instructions from the function code. However, for custom options, add a function.json that looks like the following
{
"name": String,
"runtime": RuntimeSpec,
"build": BuildSpec,
"infra": InfraSpec,
"test": TestSpec
}
RuntimeSpec
| Key | Default | Optional? | Comments |
|---|---|---|---|
| lang | Inferred | yes | |
| handler | handler.handler | ||
| package_type | zip | possible values: zip, image | |
| uri | file:./lambda.zip | ||
| mount_fs | false | yes | |
| snapstart | false | yes | |
| memory | 128 | yes | |
| timeout | 30 | yes | |
| provisioned_concurrency | 0 | yes | |
| reserved_concurrency | 0 | yes | |
| layers | [] | yes | |
| extensions | [] | yes | |
| environment | {} | yes | Environment variables |
BuildSpec
JSON Spec
{
"name": "string",
// Optional
"dir": "string",
// Optional
"description": "string",
// Optional
"namespace": "string",
// Optional
"fqn": "string",
// Optional
"layer_name": "string",
// Optional
"version": "string",
// Optional
"revision": "string",
// Optional
"runtime": {
"lang": "Python39" | "Python310" | "Python311" | "Python312" | "Python313" | "Ruby32" | "Java21" | "Rust" | "Node22" | "Node20",
"handler": "string",
"package_type": "string",
// Optional
"uri": "string",
// Optional
"mount_fs": true,
// Optional
"snapstart": true,
"layers": [
"string",
/* ... */
],
"extensions": [
"string",
/* ... */
]
},
// Optional
"build": {
"kind": "Code" | "Inline" | "Layer" | "Slab" | "Library" | "Extension" | "Runtime" | "Image",
"pre": [
"dnf install git -yy",
/* ... */
],
"post": [
"string",
/* ... */
],
// Command to use when build kind is Code
"command": "zip -9 lambda.zip *.py",
"images": {
"string": {
// Optional
"dir": "string",
// Optional
"parent": "string",
// Optional
"version": "string",
"commands": [
"string",
/* ... */
]
},
/* ... */
},
"layers": {
"string": {
"commands": [
"string",
/* ... */
]
},
/* ... */
}
},
// Optional
"infra": {
"dir": "string",
// Optional
"vars_file": "string",
"role": {
"name": "string",
"path": "string"
}
}
}