Support multiple GitHub SSH deploy keys (#568)

* add sshPublicKeysDirectoryPath and GIT_CONFIG_EXTENSIONS parameters that adds git configs and mounts .ssh/config and public keys to the container, in order to allow multiple sh deploy key trick by webplatform@ssh-agent

* remove sshPublicKeysDirectoryPath and GIT_CONFIG_EXTENSIONS from windows runner for now

src/model/docker.ts

@@ -40,7 +40,15 @@ class Docker {
     additionalVariables: StringKeyValuePair[] = [],
     entrypointBash: boolean = false,
   ): string {
-    const { workspace, actionFolder, runnerTempPath, sshAgent, gitPrivateToken, dockerWorkspacePath } = parameters;
+    const {
+      workspace,
+      actionFolder,
+      runnerTempPath,
+      sshAgent,
+      sshPublicKeysDirectoryPath,
+      gitPrivateToken,
+      dockerWorkspacePath,
+    } = parameters;
 
     const githubHome = path.join(runnerTempPath, '_github_home');
     if (!existsSync(githubHome)) mkdirSync(githubHome);
@@ -54,6 +62,7 @@ class Docker {
             ${ImageEnvironmentFactory.getEnvVarString(parameters, additionalVariables)} \
             --env UNITY_SERIAL \
             --env GITHUB_WORKSPACE=${dockerWorkspacePath} \
+            --env GIT_CONFIG_EXTENSIONS \
             ${gitPrivateToken ? `--env GIT_PRIVATE_TOKEN="${gitPrivateToken}"` : ''} \
             ${sshAgent ? '--env SSH_AUTH_SOCK=/ssh-agent' : ''} \
             --volume "${githubHome}":"/root:z" \
@@ -64,7 +73,12 @@ class Docker {
             --volume "${actionFolder}/platforms/ubuntu/entrypoint.sh:/entrypoint.sh:z" \
             --volume "${actionFolder}/unity-config:/usr/share/unity3d/config/:z" \
             ${sshAgent ? `--volume ${sshAgent}:/ssh-agent` : ''} \
-            ${sshAgent ? '--volume /home/runner/.ssh/known_hosts:/root/.ssh/known_hosts:ro' : ''} \
+            ${
+              sshAgent && !sshPublicKeysDirectoryPath
+                ? '--volume /home/runner/.ssh/known_hosts:/root/.ssh/known_hosts:ro'
+                : ''
+            } \
+            ${sshPublicKeysDirectoryPath ? `--volume ${sshPublicKeysDirectoryPath}:/root/.ssh:ro` : ''} \
             ${entrypointBash ? `--entrypoint ${commandPrefix}` : ``} \
             ${image} \
             ${entrypointBash ? `-c` : `${commandPrefix} -c`} \