Hi, I’m new to snapcraft and I’m trying to create a MongoDB snap with the latest version.
I’ve been reading through the tutorials and documentation and used this github as a start.
My changes:
Updated the version
Changed the download link
Added a base
Moved the plugins to snap/plugins
The error i’m getting:
Source path "/ssd/dev/snaps-niemeyer/mongodb/mongo42" does not exist
An error occurred with the instance when trying to mount with 'multipass': returned exit code 1.
Ensure that 'multipass' is setup correctly and try again.
Any help would be appreciated.
The snapcraft.yaml:
name: mongo42
version: 4.2.8
summary: MongoDB document-oriented database
description: |
MongoDB is a high-performance, open source, schema-free
document-oriented data store that's easy to deploy, manage
and use. It's network accessible, written in C++ and offers
the following features:
* Collection oriented storage - easy storage of object-style data
* Full index support, including on inner objects
* Query profiling
* Replication and fail-over support
* Efficient storage of binary data including large objects (e.g. videos)
* Auto-sharding for cloud-level scalability
High performance, scalability, and reasonable depth of functionality
are the goals for the project.
base: core18
grade: devel
confinement: devmode
apps:
mongo42:
command: bin/run.sh mongo
mongod:
command: bin/run.sh mongod --port=33017 --smallfiles --noprealloc
daemon: simple
d:
command: bin/run.sh mongod
s:
command: bin/run.sh mongos
export:
command: bin/run.sh mongoexport
import:
command: bin/run.sh mongoimport
dump:
command: bin/run.sh mongodump
restore:
command: bin/run.sh mongorestore
top:
command: bin/run.sh mongotop
stat:
command: bin/run.sh mongostat
perf:
command: bin/run.sh mongoperf
files:
command: bin/run.sh mongofiles
sniff:
command: bin/run.sh mongosniff
oplog:
command: bin/run.sh mongooplog
plugs:
home:
network:
network-bind:
parts:
mongodb:
# source: https://fastdl.mongodb.org/linux/mongodb-linux-aarch64-ubuntu1804-4.2.8.tgz
source: https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu1804-4.2.8.tgz
plugin: dump
stage-packages:
# - libc6 leads to warning "libc6 has been staged into the snap: only do this if you know what what you are doing." and a segfault when running
- libssl1.1
content:
source: ../content
plugin: dump
Multipass (the system that operates the Virtual Machines for Snapcraft) is strictly-confined, which means that it can only access specific locations on your filesystem. According to snap connections multipass the only available interface for filesystem allowance is home which grants permission for multipass to read files in /home/$USER/* (excluding /home/$USER/.* - i.e. files and folders in your home folder that begin with a dot/period: .) It does include multipass-support which might grant further filesystem locations, but I’m not sure if or what those are.
Ideally multipass should also include the removable-media plug, which allows access to filesystems at /media/$USER/* and GVFS-mounted filesystems on a desktop at /run/user/$UID/gvfs/*, but this appears to not be the case, currently. I’m not sure who to ping to get that added, so I’ll ping my favourite pingee @popey because he’s awesome and knows all ;-p
I thought the plug “home” would fix the permission.
Regarding the GLIBC error, I just got a hint while messing around: The linker version '2.23' used by the base 'core' is incompatible with files in this snap:
Guess it’s not about the libc.so on my system, but about the one used by the base?
The core* bases are build from respective Ubuntu releases. The core is basd on Ubuntu 16.04, core18 is Ubuntu 18.04, core20 is Ubuntu 20.04. Looking at the prebuilt mongdb URL you used which is https://fastdl.mongodb.org/linux/mongodb-linux-x86_64-ubuntu1804-4.2.8.tgz I would guess the binary was built on Ubuntu 18.04, meaning you need to use core18.
I guessed that when removing base: core18 , it was using ubuntu 16 indeed, leading to the libc error. I updated my first post.
I’m still stuck however, at the error Source path "/ssd/dev/snaps-niemeyer/mongodb/mongo42" does not exist. I don’t know what is trying to access that. Does it have anything to do with how the dump.py or run.sh is made?
I think multipass (which is a strictly confined snap now), is unable to access /ssd/dev/snaps-niemeyer/mongodb/mongo42. Since /ssd/dev/ is just some random path in your system, snap do not know whether it contains sensitive data and if so, what data, or whether any interface should allow accessing it, so it is not available in the filesystem view that multipass can observe.
That being said, multipass, plugs the home interface as @lucyllewy indicated (see docs here). Moving the source tree to your $HOME and building from that location should make it work.
Ah, now I get it. I completely forgot that multipass itself is a snap. Shame though, as my home dir isn’t on an sdd. But thanks a lot, will give it a try!
I’d guess snapcraft has only set up multipass to access the directory tree with root at where snapcraft.yaml is. However, snapcraft.yaml references ../content which is a level up. You probably need to tweak the file to make it do what you want and how you build it.
Another step ahead Moving the content dir to where the yaml is located, did the job.
What is the normal way of adding binaries like that?
Creating the snap now finishes, but when running it, i get the error:
/snap/mongo42/x3/bin/mongo: error while loading shared libraries: libcurl.so.4: cannot open shared object file: No such file or directory
Pulling mongodb
Downloading 'mongodb-linux-x86_64-ubuntu1804-4.2.8.tgz'[==============================================================================================================================================] 100%
Building content
Building mongodb
Staging content
Staging mongodb
Priming content
Priming mongodb
This part is missing libraries that cannot be satisfied with any available stage-packages known to snapcraft:
- libpcap.so.0.8
These dependencies can be satisfied via additional parts or content sharing. Consider validating configured filesets if this dependency was built.
A shell wrapper will be generated for command 'bin/run.sh mongod --port=33017 --smallfiles --noprealloc' as it does not conform with the command pattern expected by the runtime. Commands must be relative to the prime directory and can only consist of alphanumeric characters, spaces, and the following special characters: / . _ # : $ -
Snapping |
Snapped mongo42_4.2.8_amd64.snap
And running it gives me a connection error, which I guess is caused by some missing interfaces?
$ mongo42
MongoDB shell version v4.2.8
connecting to: mongodb://127.0.0.1:42017/?compressors=disabled&gssapiServiceName=mongodb
2020-07-27T13:53:55.669+0200 E QUERY [js] Error: couldn't connect to server 127.0.0.1:42017, connection attempt failed: SocketException: Error connecting to 127.0.0.1:42017 :: caused by :: Connection refused :
connect@src/mongo/shell/mongo.js:341:17
@(connect):2:6
2020-07-27T13:53:55.670+0200 F - [main] exception: connect failed
2020-07-27T13:53:55.670+0200 E - [main] exiting with code 1
Moving the content dir to where the yaml is located, did the job.