Add context input (#16)

Signed-off-by: CrazyMax <crazy-max@users.noreply.github.com>

README.md

@@ -128,12 +128,13 @@ Following inputs can be used as `step.with` keys
 
 | Name               | Type    | Description                       |
 |--------------------|---------|-----------------------------------|
-| `version`          | String  | [Buildx](https://github.com/docker/buildx) version. (e.g. `v0.3.0`, `latest`) |
+| `version`          | String  | [Buildx](https://github.com/docker/buildx) version. (eg. `v0.3.0`, `latest`) |
 | `driver`           | String  | Sets the [builder driver](https://github.com/docker/buildx#--driver-driver) to be used (default `docker-container`) |
-| `driver-opts`      | CSV     | List of additional [driver-specific options](https://github.com/docker/buildx#--driver-opt-options) |
+| `driver-opts`      | CSV     | List of additional [driver-specific options](https://github.com/docker/buildx#--driver-opt-options) (eg. `image=moby/buildkit:master`) |
 | `buildkitd-flags`  | String  | [Flags for buildkitd](https://github.com/moby/buildkit/blob/master/docs/buildkitd.toml.md) daemon (since [buildx v0.3.0](https://github.com/docker/buildx/releases/tag/v0.3.0)) |
 | `install`          | Bool    | Sets up `docker build` command as an alias to `docker buildx` (default `false`) |
 | `use`              | Bool    | Switch to this builder instance (default `true`) |
+| `context`          | String  | [Name of a context](https://github.com/docker/buildx#buildx-create-options-contextendpoint) from `docker context ls` or an endpoint as the address for docker socket (eg. `DOCKER_HOST` value) |
 
 > `CSV` type must be a newline-delimited string
 > ```yaml

action.yml

@@ -8,14 +8,14 @@ branding:
 
 inputs:
   version:
-    description: 'Buildx version. e.g. v0.3.0'
+    description: 'Buildx version. (eg. v0.3.0)'
     required: false
   driver:
     description: 'Sets the builder driver to be used'
     default: 'docker-container'
     required: false
   driver-opts:
-    description: 'List of additional driver-specific options. Eg. image=moby/buildkit:master'
+    description: 'List of additional driver-specific options. (eg. image=moby/buildkit:master)'
     required: false
   buildkitd-flags:
     description: 'Flags for buildkitd daemon'
@@ -29,6 +29,9 @@ inputs:
     description: 'Switch to this builder instance'
     default: 'true'
     required: false
+  context:
+    description: 'Name of a context from docker context ls or an endpoint as the address for docker socket (eg. DOCKER_HOST value)'
+    required: false
 
 outputs:
   name:

src/context.ts

@@ -10,6 +10,7 @@ export interface Inputs {
   buildkitdFlags: string;
   install: boolean;
   use: boolean;
+  context: string;
 }
 
 export async function getInputs(): Promise<Inputs> {
@@ -21,7 +22,8 @@ export async function getInputs(): Promise<Inputs> {
       core.getInput('buildkitd-flags') ||
       '--allow-insecure-entitlement security.insecure --allow-insecure-entitlement network.host',
     install: /true/i.test(core.getInput('install')),
-    use: /true/i.test(core.getInput('use'))
+    use: /true/i.test(core.getInput('use')),
+    context: core.getInput('context')
   };
 }
 

src/main.ts

@@ -42,6 +42,9 @@ async function run(): Promise<void> {
       if (inputs.use) {
         createArgs.push('--use');
       }
+      if (inputs.context) {
+        createArgs.push(inputs.context);
+      }
       await exec.exec('docker', createArgs);
 
       core.info('🏃 Booting builder...');