Merge pull request #18 from ba32107/add_signkey_env_var

Add SIGN_KEY environment variable to choose GPG signing key

Author: TheAssassin

README.md

@@ -35,5 +35,6 @@ linuxdeploy-plugin-appimage can be configured using environment variables.
 
 - `UPDATE_INFORMATION="..."`: embed [update information](https://github.com/AppImage/AppImageSpec/blob/master/draft.md#update-information) in the AppImage, and generate corresponding `.zsync` file
 - `SIGN=1`: set this variable to any value to enable signing of the AppImage
+- `SIGN_KEY=key_id`: GPG Key ID to use for signing. This environment variable is only used if `SIGN` is set.
 - `VERBOSE=1`: set this variable to any value to enable verbose output
 - `OUTPUT=filename`: change filename of resulting AppImage

src/main.cpp

@@ -113,6 +113,12 @@ int main(const int argc, const char* const* const argv) {
 
     if (getenv("SIGN") != nullptr) {
         args.push_back(strdup("-s"));
+
+        const char* signingKey;
+        if ((signingKey = getenv("SIGN_KEY")) != nullptr) {
+            args.push_back(strdup("--sign-key"));
+            args.push_back(strdup(signingKey));
+        }
     }
 
     if (getenv("VERBOSE") != nullptr) {