Save BuildKit state on client for cache support

README.md

@@ -197,8 +197,11 @@ Following inputs can be used as `step.with` keys
 | `endpoint`         | String  | [Optional address for docker socket](https://github.com/docker/buildx/blob/master/docs/reference/buildx_create.md#description) or context from `docker context ls` |
 | `config`           | String  | [BuildKit config file](https://github.com/docker/buildx/blob/master/docs/reference/buildx_create.md#config) |
 | `config-inline`    | String  | Same as `config` but inline |
+| `state-dir`        | String  | Path to [BuildKit state volume](https://github.com/docker/buildx/blob/master/docs/reference/buildx_rm.md#-keep-buildkit-state---keep-state) directory |
 
-> `config` and `config-inline` are mutually exclusive.
+> :bulb: `config` and `config-inline` are mutually exclusive.
+
+> :bulb: `state-dir` can only be used with the `docker-container` driver and a builder with a single node.
 
 > `CSV` type must be a newline-delimited string
 > ```yaml

action.yml

@@ -38,6 +38,9 @@ inputs:
   config-inline:
     description: 'Inline BuildKit config'
     required: false
+  state-dir:
+    description: 'Path to BuildKit state volume directory'
+    required: false
 
 outputs:
   name:

src/buildx.ts

@@ -3,11 +3,16 @@ import * as path from 'path';
 import * as semver from 'semver';
 import * as util from 'util';
 import * as context from './context';
+import * as docker from './docker';
 import * as git from './git';
 import * as github from './github';
 import * as core from '@actions/core';
 import * as exec from '@actions/exec';
 import * as tc from '@actions/tool-cache';
+import child_process from 'child_process';
+
+const uid = parseInt(child_process.execSync(`id -u`, {encoding: 'utf8'}).trim());
+const gid = parseInt(child_process.execSync(`id -g`, {encoding: 'utf8'}).trim());
 
 export type Builder = {
   name?: string;
@@ -81,6 +86,19 @@ export function satisfies(version: string, range: string): boolean {
   return semver.satisfies(version, range) || /^[0-9a-f]{7}$/.exec(version) !== null;
 }
 
+export async function createStateVolume(stateDir: string, nodeName: string): Promise<void> {
+  return await docker.volumeCreate(stateDir, `${nodeName}_state`);
+}
+
+export async function saveStateVolume(dir: string, nodeName: string): Promise<void> {
+  const ctnid = await docker.containerCreate('busybox', `${nodeName}_state:/data`);
+  const outdir = await docker.containerCopy(ctnid, `${ctnid}:/data`);
+  await docker.volumeRemove(`${nodeName}_state`);
+  fs.rmdirSync(dir, {recursive: true});
+  fs.renameSync(outdir, dir);
+  await docker.containerRemove(ctnid);
+}
+
 export async function inspect(name: string): Promise<Builder> {
   return await exec
     .getExecOutput(`docker`, ['buildx', 'inspect', name], {

src/context.ts

@@ -30,6 +30,7 @@ export interface Inputs {
   endpoint: string;
   config: string;
   configInline: string;
+  stateDir: string;
 }
 
 export async function getInputs(): Promise<Inputs> {
@@ -42,7 +43,8 @@ export async function getInputs(): Promise<Inputs> {
     use: core.getBooleanInput('use'),
     endpoint: core.getInput('endpoint'),
     config: core.getInput('config'),
-    configInline: core.getInput('config-inline')
+    configInline: core.getInput('config-inline'),
+    stateDir: core.getInput('state-dir')
   };
 }
 

src/docker.ts

@@ -0,0 +1,71 @@
+import * as fs from 'fs';
+import * as path from 'path';
+import * as uuid from 'uuid';
+import * as context from './context';
+import * as exec from '@actions/exec';
+
+export async function volumeCreate(dir: string, name: string): Promise<void> {
+  if (!fs.existsSync(dir)) {
+    fs.mkdirSync(dir, {recursive: true});
+  }
+  return await exec
+    .getExecOutput(`docker`, ['volume', 'create', '--name', `${name}`, '--driver', 'local', '--opt', `o=bind,acl`, '--opt', 'type=none', '--opt', `device=${dir}`], {
+      ignoreReturnCode: true
+    })
+    .then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        throw new Error(res.stderr.trim());
+      }
+    });
+}
+
+export async function volumeRemove(name: string): Promise<void> {
+  return await exec
+    .getExecOutput(`docker`, ['volume', 'rm', '-f', `${name}`], {
+      ignoreReturnCode: true
+    })
+    .then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        throw new Error(res.stderr.trim());
+      }
+    });
+}
+
+export async function containerCreate(image: string, volume: string): Promise<string> {
+  return await exec
+    .getExecOutput(`docker`, ['create', '--rm', '-v', `${volume}`, `${image}`], {
+      ignoreReturnCode: true
+    })
+    .then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        throw new Error(res.stderr.trim());
+      }
+      return res.stdout.trim();
+    });
+}
+
+export async function containerCopy(ctnid: string, src: string): Promise<string> {
+  const outdir = path.join(context.tmpDir(), `ctn-copy-${uuid.v4()}`).split(path.sep).join(path.posix.sep);
+  return await exec
+    .getExecOutput(`docker`, ['cp', '-a', `${src}`, `${outdir}`], {
+      ignoreReturnCode: true
+    })
+    .then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        throw new Error(res.stderr.trim());
+      }
+      return outdir;
+    });
+}
+
+export async function containerRemove(ctnid: string): Promise<void> {
+  return await exec
+    .getExecOutput(`docker`, ['rm', '-f', '-v', `${ctnid}`], {
+      ignoreReturnCode: true
+    })
+    .then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        throw new Error(res.stderr.trim());
+      }
+    });
+}

src/main.ts

@@ -16,8 +16,10 @@ async function run(): Promise<void> {
     core.endGroup();
 
     const inputs: context.Inputs = await context.getInputs();
-    const dockerConfigHome: string = process.env.DOCKER_CONFIG || path.join(os.homedir(), '.docker');
+    const builderName: string = inputs.driver == 'docker' ? 'default' : `builder-${uuid.v4()}`;
+    stateHelper.setStateDir(inputs.stateDir);
 
+    const dockerConfigHome: string = process.env.DOCKER_CONFIG || path.join(os.homedir(), '.docker');
     if (util.isValidUrl(inputs.version)) {
       core.startGroup(`Build and install buildx`);
       await buildx.build(inputs.version, dockerConfigHome);
@@ -29,11 +31,15 @@ async function run(): Promise<void> {
     }
 
     const buildxVersion = await buildx.getVersion();
-    const builderName: string = inputs.driver == 'docker' ? 'default' : `builder-${uuid.v4()}`;
     context.setOutput('name', builderName);
     stateHelper.setBuilderName(builderName);
 
     if (inputs.driver !== 'docker') {
+      if (inputs.stateDir.length > 0) {
+        await core.group(`Creating BuildKit state volume from ${inputs.stateDir}`, async () => {
+          await buildx.createStateVolume(inputs.stateDir, `buildx_buildkit_${builderName}0`);
+        });
+      }
       core.startGroup(`Creating a new builder instance`);
       const createArgs: Array<string> = ['buildx', 'create', '--name', builderName, '--driver', inputs.driver];
       if (buildx.satisfies(buildxVersion, '>=0.3.0')) {
@@ -114,8 +120,12 @@ async function cleanup(): Promise<void> {
 
   if (stateHelper.builderName.length > 0) {
     core.startGroup(`Removing builder`);
+    const rmArgs: Array<string> = ['buildx', 'rm', `${stateHelper.builderName}`];
+    if (stateHelper.stateDir.length > 0) {
+      rmArgs.push('--keep-state');
+    }
     await exec
-      .getExecOutput('docker', ['buildx', 'rm', `${stateHelper.builderName}`], {
+      .getExecOutput('docker', rmArgs, {
         ignoreReturnCode: true
       })
       .then(res => {
@@ -125,6 +135,12 @@ async function cleanup(): Promise<void> {
       });
     core.endGroup();
   }
+
+  if (stateHelper.stateDir.length > 0) {
+    core.startGroup(`Saving state volume`);
+    await buildx.saveStateVolume(stateHelper.stateDir, stateHelper.containerName);
+    core.endGroup();
+  }
 }
 
 if (!stateHelper.IsPost) {

src/state-helper.ts

@@ -2,8 +2,10 @@ import * as core from '@actions/core';
 
 export const IsPost = !!process.env['STATE_isPost'];
 export const IsDebug = !!process.env['STATE_isDebug'];
+
 export const builderName = process.env['STATE_builderName'] || '';
 export const containerName = process.env['STATE_containerName'] || '';
+export const stateDir = process.env['STATE_stateDir'] || '';
 
 export function setDebug(debug: string) {
   core.saveState('isDebug', debug);
@@ -17,6 +19,10 @@ export function setContainerName(containerName: string) {
   core.saveState('containerName', containerName);
 }
 
+export function setStateDir(stateDir: string) {
+  core.saveState('stateDir', stateDir);
+}
+
 if (!IsPost) {
   core.saveState('isPost', 'true');
 }