Flatpak - Safely Relocate Sandboxed Home Directory
I would like to transparently provide a Flatpak app with a fully sandboxed ~/ directory located at an arbitrary location of my choosing.
- That is, I want to sandbox the entirety of
~/such that writing to arbitrary subdirectories works as expected, and map it to a location on an external disk (mounted at/mnt/<disk-id>) instead of~/.var/app/<app-id>. - Ideally I'd like to relocate all of the per-user data for a particular app, but I'm trying to limit the scope of this question.
- I know that I can grant access to arbitrary locations via
--filesystem=<path>and that I can map individual subdirectories under user~/to the corresponding sandbox directory via--persist=<path>. However, neither of these options would appear to satisfy my use case.
The Flatpak docs (sandbox permissions and flatpak-override) seem to indicate that the sandbox uses a tempfs and only bind mounts specific directories into it. In particular, the flatpak-override --persist docs seem to imply that individual subdirectories must be mapped on a case by case basis in order for data to be persisted. Contradicting this, the sandbox overview seems to be saying that ~/.var/app/<app-id> is simply bind mounted to sandbox ~/. The latter appears to be what actually happens. When I used a sandboxed app to create a directory within ~/ that had not been mapped into the sandbox, the corresponding directory was created under ~/.var/app/<app-id> and persisted across app restarts.
Given the apparent behavior, would it be safe to simply bind mount the desired location to ~/.var/app/<app-id>? I'm hesitant to blindly attempt this because I know that Flatpak is engaging in a great deal of file system shenanigans under the hood in order to create a robust sandbox. In particular, it pivot_roots the sandbox filesystem, would be bind mounting the location I had bind mounted to (do I need an rbind here?), could be performing further bind mounts in subdirectories (will this play well with my bind mount?), and is likely taking other precautions (now or in the future) which I'm worried might break any indirections done by me in strange and creative ways.
linux software-installation package-management flatpak
asked yesterday
AnOccasionalCashewAnOccasionalCashew
1063
New contributor
AnOccasionalCashew is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I would like to transparently provide a Flatpak app with a fully sandboxed ~/ directory located at an arbitrary location of my choosing.
- That is, I want to sandbox the entirety of
~/such that writing to arbitrary subdirectories works as expected, and map it to a location on an external disk (mounted at/mnt/<disk-id>) instead of~/.var/app/<app-id>. - Ideally I'd like to relocate all of the per-user data for a particular app, but I'm trying to limit the scope of this question.
- I know that I can grant access to arbitrary locations via
--filesystem=<path>and that I can map individual subdirectories under user~/to the corresponding sandbox directory via--persist=<path>. However, neither of these options would appear to satisfy my use case.
The Flatpak docs (sandbox permissions and flatpak-override) seem to indicate that the sandbox uses a tempfs and only bind mounts specific directories into it. In particular, the flatpak-override --persist docs seem to imply that individual subdirectories must be mapped on a case by case basis in order for data to be persisted. Contradicting this, the sandbox overview seems to be saying that ~/.var/app/<app-id> is simply bind mounted to sandbox ~/. The latter appears to be what actually happens. When I used a sandboxed app to create a directory within ~/ that had not been mapped into the sandbox, the corresponding directory was created under ~/.var/app/<app-id> and persisted across app restarts.
Given the apparent behavior, would it be safe to simply bind mount the desired location to ~/.var/app/<app-id>? I'm hesitant to blindly attempt this because I know that Flatpak is engaging in a great deal of file system shenanigans under the hood in order to create a robust sandbox. In particular, it pivot_roots the sandbox filesystem, would be bind mounting the location I had bind mounted to (do I need an rbind here?), could be performing further bind mounts in subdirectories (will this play well with my bind mount?), and is likely taking other precautions (now or in the future) which I'm worried might break any indirections done by me in strange and creative ways.
linux software-installation package-management flatpak
asked yesterday
AnOccasionalCashewAnOccasionalCashew
1063
New contributor
AnOccasionalCashew is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
I would like to transparently provide a Flatpak app with a fully sandboxed ~/ directory located at an arbitrary location of my choosing.
- That is, I want to sandbox the entirety of
~/such that writing to arbitrary subdirectories works as expected, and map it to a location on an external disk (mounted at/mnt/<disk-id>) instead of~/.var/app/<app-id>. - Ideally I'd like to relocate all of the per-user data for a particular app, but I'm trying to limit the scope of this question.
- I know that I can grant access to arbitrary locations via
--filesystem=<path>and that I can map individual subdirectories under user~/to the corresponding sandbox directory via--persist=<path>. However, neither of these options would appear to satisfy my use case.
The Flatpak docs (sandbox permissions and flatpak-override) seem to indicate that the sandbox uses a tempfs and only bind mounts specific directories into it. In particular, the flatpak-override --persist docs seem to imply that individual subdirectories must be mapped on a case by case basis in order for data to be persisted. Contradicting this, the sandbox overview seems to be saying that ~/.var/app/<app-id> is simply bind mounted to sandbox ~/. The latter appears to be what actually happens. When I used a sandboxed app to create a directory within ~/ that had not been mapped into the sandbox, the corresponding directory was created under ~/.var/app/<app-id> and persisted across app restarts.
Given the apparent behavior, would it be safe to simply bind mount the desired location to ~/.var/app/<app-id>? I'm hesitant to blindly attempt this because I know that Flatpak is engaging in a great deal of file system shenanigans under the hood in order to create a robust sandbox. In particular, it pivot_roots the sandbox filesystem, would be bind mounting the location I had bind mounted to (do I need an rbind here?), could be performing further bind mounts in subdirectories (will this play well with my bind mount?), and is likely taking other precautions (now or in the future) which I'm worried might break any indirections done by me in strange and creative ways.
linux software-installation package-management flatpak
asked yesterday
AnOccasionalCashewAnOccasionalCashew
1063
New contributor
AnOccasionalCashew is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
I would like to transparently provide a Flatpak app with a fully sandboxed ~/ directory located at an arbitrary location of my choosing.
- That is, I want to sandbox the entirety of
~/such that writing to arbitrary subdirectories works as expected, and map it to a location on an external disk (mounted at/mnt/<disk-id>) instead of~/.var/app/<app-id>. - Ideally I'd like to relocate all of the per-user data for a particular app, but I'm trying to limit the scope of this question.
- I know that I can grant access to arbitrary locations via
--filesystem=<path>and that I can map individual subdirectories under user~/to the corresponding sandbox directory via--persist=<path>. However, neither of these options would appear to satisfy my use case.
The Flatpak docs (sandbox permissions and flatpak-override) seem to indicate that the sandbox uses a tempfs and only bind mounts specific directories into it. In particular, the flatpak-override --persist docs seem to imply that individual subdirectories must be mapped on a case by case basis in order for data to be persisted. Contradicting this, the sandbox overview seems to be saying that ~/.var/app/<app-id> is simply bind mounted to sandbox ~/. The latter appears to be what actually happens. When I used a sandboxed app to create a directory within ~/ that had not been mapped into the sandbox, the corresponding directory was created under ~/.var/app/<app-id> and persisted across app restarts.
Given the apparent behavior, would it be safe to simply bind mount the desired location to ~/.var/app/<app-id>? I'm hesitant to blindly attempt this because I know that Flatpak is engaging in a great deal of file system shenanigans under the hood in order to create a robust sandbox. In particular, it pivot_roots the sandbox filesystem, would be bind mounting the location I had bind mounted to (do I need an rbind here?), could be performing further bind mounts in subdirectories (will this play well with my bind mount?), and is likely taking other precautions (now or in the future) which I'm worried might break any indirections done by me in strange and creative ways.
linux software-installation package-management flatpak
linux software-installation package-management flatpak
asked yesterday
AnOccasionalCashewAnOccasionalCashew
1063
New contributor
AnOccasionalCashew is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked yesterday
AnOccasionalCashewAnOccasionalCashew
1063
New contributor
AnOccasionalCashew is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
edited 2 hours ago
AnOccasionalCashew
asked yesterday
AnOccasionalCashewAnOccasionalCashew
1063
New contributor
AnOccasionalCashew is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
asked yesterday
AnOccasionalCashewAnOccasionalCashew
1063
asked yesterday
AnOccasionalCashewAnOccasionalCashew
1063
1063
New contributor
AnOccasionalCashew is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
New contributor
AnOccasionalCashew is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
AnOccasionalCashew is a new contributor to this site. Take care in asking for clarification, commenting, and answering.
Check out our Code of Conduct.
add a comment |
add a comment |
0
active
oldest
votes
Your Answer
StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "106"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);
StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});
function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: false,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: null,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});
}
});
AnOccasionalCashew is a new contributor. Be nice, and check out our Code of Conduct.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f502434%2fflatpak-safely-relocate-sandboxed-home-directory%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
0
active
oldest
votes
0
active
oldest
votes
active
oldest
votes
active
oldest
votes
AnOccasionalCashew is a new contributor. Be nice, and check out our Code of Conduct.
AnOccasionalCashew is a new contributor. Be nice, and check out our Code of Conduct.
AnOccasionalCashew is a new contributor. Be nice, and check out our Code of Conduct.
AnOccasionalCashew is a new contributor. Be nice, and check out our Code of Conduct.
Thanks for contributing an answer to Unix & Linux Stack Exchange!
- Please be sure to answer the question. Provide details and share your research!
But avoid …
- Asking for help, clarification, or responding to other answers.
- Making statements based on opinion; back them up with references or personal experience.
To learn more, see our tips on writing great answers.
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2funix.stackexchange.com%2fquestions%2f502434%2fflatpak-safely-relocate-sandboxed-home-directory%23new-answer', 'question_page');
}
);
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Sign up or log in
StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Sign up using Google
Sign up using Facebook
Sign up using Email and Password
Post as a guest
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
Required, but never shown
