Micromamba
Contents
Micromamba#
micromamba is a small, pure-C++ executable with enough functionalities to bootstrap fully functional conda-environments.
Still at early stage, it’s main usage is in continous integration pipelines: since it’s a single executable, it reduces dramatically bandwidth usage and provide fast operations.
Quickstarts#
micromamba supports a subset of all mamba or conda commands and implements a command line interface from scratch.micromamba --help:$ micromamba --help
Subcommands:
shell Generate shell init scripts
create Create new environment
install Install packages in active environment
update Update packages in active environment
repoquery Find and analyze packages in active environment or channels
remove Remove packages from active environment
list List packages in active environment
package Extract a package or bundle files into an archive
clean Clean package cache
config Configuration of micromamba
info Information about micromamba
constructor Commands to support using micromamba in constructor
env List environments
activate Activate an environment
run Run an executable in an environment
ps Show, inspect or kill running processes
auth Login or logout of a given host
search Find packages in active environment or channels
To activate an environment just call micromamba activate /path/to/env or, when it’s a named environment in your root prefix, then you can also use micromamba activate myenv.
micromamba expects to find the root prefix set by $MAMBA_ROOT_PREFIX environment variable. You can also provide it using CLI option -r,--root-prefix.
Named environments then live in$MAMBA_ROOT_PREFIX/envs/.
For more details, please read about configuration.
After activation, you can run install to add new packages to the environment.
$ micromamba install xtensor -c conda-forge
Using create, you can also create environments:
$ micromamba create -n xtensor_env xtensor xsimd -c conda-forge
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conda-forge/noarch [====================] (00m:01s) Done
conda-forge/linux-64 [====================] (00m:04s) Done
Transaction
Prefix: /home/wolfv/miniconda3/envs/xtensor_env
Updating specs:
- xtensor
- xsimd
Package Version Build Channel Size
────────────────────────────────────────────────────────────────────────
Install:
────────────────────────────────────────────────────────────────────────
_libgcc_mutex 0.1 conda_forge conda-forge/linux-64 Cached
_openmp_mutex 4.5 1_gnu conda-forge/linux-64 Cached
libgcc-ng 9.3.0 h5dbcf3e_17 conda-forge/linux-64 Cached
libgomp 9.3.0 h5dbcf3e_17 conda-forge/linux-64 Cached
libstdcxx-ng 9.3.0 h2ae2ef3_17 conda-forge/linux-64 Cached
xsimd 7.4.9 hc9558a2_0 conda-forge/linux-64 102 KB
xtensor 0.21.9 h0efe328_0 conda-forge/linux-64 183 KB
xtl 0.6.21 h0efe328_0 conda-forge/linux-64 Cached
Summary:
Install: 8 packages
Total download: 285 KB
────────────────────────────────────────────────────────────────────────
Confirm changes: [Y/n] ...
After the installation is finished, the environment can be activated with:
$ micromamba activate xtensor_env
Specification files#
The create syntax also allows you to use specification or environment files (also called spec files) to easily re-create environments.
The three supported syntaxes are: yaml, txt and explicit spec files.
Simple text spec files#
The txt file contains one spec per line. For example, this could look like:
xtensor
numpy 1.19
xsimd >=7.4
To use this file, pass:
$ micromamba create -n from_file -f spec_file.txt -c conda-forge
Note
You can pass multiple text spec files by repeating the -f,--file argument.
YAML spec files#
More powerful are YAML files like the following, because they already contain a desired environment name and the channels to use:
name: testenv
channels:
- conda-forge
dependencies:
- python >=3.6,<3.7
- ipykernel >=5.1
- ipywidgets
They are used the same way as text files:
$ micromamba create -f env.yml
Note
CLI options will keep precedence over target prefix or channels specified in spec files.
Warning
YAML spec files do not allow multiple files.
Explicit spec files#
Using conda you can generate explicit environment lock files. For this, create an environment and execute:
$ conda list --explicit --md5
These environment files look like the following and precisely “pin” the desired package + version + build string:
# This file may be used to create an environment using:
# $ conda create --name <env> --file <this file>
# platform: linux-64
@EXPLICIT
https://conda.anaconda.org/conda-forge/linux-64/_libgcc_mutex-0.1-conda_forge.tar.bz2#d7c89558ba9fa0495403155b64376d81
https://conda.anaconda.org/conda-forge/linux-64/libstdcxx-ng-9.3.0-h2ae2ef3_17.tar.bz2#342f3c931d0a3a209ab09a522469d20c
https://conda.anaconda.org/conda-forge/linux-64/libgomp-9.3.0-h5dbcf3e_17.tar.bz2#8fd587013b9da8b52050268d50c12305
https://conda.anaconda.org/conda-forge/linux-64/_openmp_mutex-4.5-1_gnu.tar.bz2#561e277319a41d4f24f5c05a9ef63c04
https://conda.anaconda.org/conda-forge/linux-64/libgcc-ng-9.3.0-h5dbcf3e_17.tar.bz2#fc9f5adabc4d55cd4b491332adc413e0
https://conda.anaconda.org/conda-forge/linux-64/xtl-0.6.21-h0efe328_0.tar.bz2#9eee90b98fd394db7a049792e67e1659
https://conda.anaconda.org/conda-forge/linux-64/xtensor-0.21.8-hc9558a2_0.tar.bz2#1030174db5c183f3afb4181a0a02873d
To install such a file with micromamba, just pass the -f flag again:
$ micromamba create -n xtensor -c conda-forge -f explicit_env.txt