exposing env variables from runner with DOCKER_ envs to respect docker options set on host (#40)

* exposing env variables from runner with DOCKER_ prefix to respect rootless docker

* Prioritize DOCKER cli over workflow envs

* formatted

packages/docker/tests/utils-test.ts

@@ -1,4 +1,4 @@
-import { sanitize } from '../src/utils'
+import { optionsWithDockerEnvs, sanitize } from '../src/utils'
 
 describe('Utilities', () => {
   it('should return sanitized image name', () => {
@@ -9,4 +9,41 @@ describe('Utilities', () => {
     const validStr = 'teststr8_one'
     expect(sanitize(validStr)).toBe(validStr)
   })
+
+  describe('with docker options', () => {
+    it('should augment options with docker environment variables', () => {
+      process.env.DOCKER_HOST = 'unix:///run/user/1001/docker.sock'
+      process.env.DOCKER_NOTEXIST = 'notexist'
+
+      const optionDefinitions: any = [
+        undefined,
+        {},
+        { env: {} },
+        { env: { DOCKER_HOST: 'unix://var/run/docker.sock' } }
+      ]
+      for (const opt of optionDefinitions) {
+        let options = optionsWithDockerEnvs(opt)
+        expect(options).toBeDefined()
+        expect(options?.env).toBeDefined()
+        expect(options?.env?.DOCKER_HOST).toBe(process.env.DOCKER_HOST)
+        expect(options?.env?.DOCKER_NOTEXIST).toBeUndefined()
+      }
+    })
+
+    it('should not overwrite other options', () => {
+      process.env.DOCKER_HOST = 'unix:///run/user/1001/docker.sock'
+      const opt = {
+        workingDir: 'test',
+        input: Buffer.from('test')
+      }
+
+      const options = optionsWithDockerEnvs(opt)
+      expect(options).toBeDefined()
+      expect(options?.workingDir).toBe(opt.workingDir)
+      expect(options?.input).toBe(opt.input)
+      expect(options?.env).toStrictEqual({
+        DOCKER_HOST: process.env.DOCKER_HOST
+      })
+    })
+  })
 })