Make (most) containers run with a read-only filesystem

This commit is contained in:
Slavi Pantaleev 2019-01-29 18:52:02 +02:00
parent b77b967171
commit 0be7b25c64
14 changed files with 49 additions and 14 deletions

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@ -1,13 +1,18 @@
# 2019-01-xx
# 2019-01-29
## Running container processes as non-root
## Running container processes as non-root, without capabilities and read-only
To improve security, this playbook no longer starts container processes as the `root` user.
Most containers were dropping privileges anyway, but we were trusting them with `root` privileges until they would do that.
Not anymore -- container processes now start as a non-root user (usually `matrix`) from the get-go.
For additional security, various [capabilities are also dropped](https://github.com/projectatomic/atomic-site/issues/203) for all containers.
For additional security, various capabilities are also dropped (see [why it's important](https://github.com/projectatomic/atomic-site/issues/203)) for all containers.
Additionally, most containers now use a read-only filesystem (see [why it's important](https://www.projectatomic.io/blog/2015/12/making-docker-images-write-only-in-production/)).
Containers are given write access only to the directories they need to write to.
A minor breaking change is the `matrix_nginx_proxy_proxy_matrix_client_api_client_max_body_size` variable having being renamed to `matrix_nginx_proxy_proxy_matrix_client_api_client_max_body_size_mb` (note the `_mb` suffix). The new variable expects a number value (e.g. `25M` -> `25`).
If you weren't customizing this variable, this wouldn't affect you.
## matrix-mailer is now based on Exim, not Postfix

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@ -158,7 +158,7 @@ matrix_nginx_proxy_enabled: true
matrix_nginx_proxy_proxy_matrix_client_api_addr_with_container: "{{ 'matrix-corporal:41080' if matrix_corporal_enabled else 'matrix-synapse:8008' }}"
matrix_nginx_proxy_proxy_matrix_client_api_addr_sans_container: "{{ 'localhost:41080' if matrix_corporal_enabled else 'localhost:8008' }}"
matrix_nginx_proxy_proxy_matrix_client_api_client_max_body_size: "{{ matrix_synapse_max_upload_size_mb }}M"
matrix_nginx_proxy_proxy_matrix_client_api_client_max_body_size_mb: "{{ matrix_synapse_max_upload_size_mb }}"
matrix_nginx_proxy_proxy_matrix_enabled: true
matrix_nginx_proxy_proxy_riot_enabled: "{{ matrix_riot_web_enabled }}"

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@ -13,6 +13,7 @@ ExecStart=/usr/bin/docker run --rm --name matrix-corporal \
--log-driver=none \
--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
--cap-drop=ALL \
--read-only \
--network={{ matrix_docker_network }} \
{% if matrix_corporal_container_expose_ports %}
-p 127.0.0.1:41080:41080 \

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@ -13,6 +13,8 @@ ExecStart=/usr/bin/docker run --rm --name matrix-coturn \
--log-driver=none \
--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
--cap-drop=ALL \
--read-only \
--tmpfs=/var/tmp:rw,noexec,nosuid,size=100m \
-p 3478:3478 \
-p 3478:3478/udp \
-p {{ matrix_coturn_turn_udp_min_port }}-{{ matrix_coturn_turn_udp_max_port }}:{{ matrix_coturn_turn_udp_min_port }}-{{ matrix_coturn_turn_udp_max_port }}/udp \

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@ -11,6 +11,8 @@ ExecStart=/usr/bin/docker run --rm --name matrix-mailer \
--log-driver=none \
--user={{ matrix_mailer_container_user_uid }}:{{ matrix_mailer_container_user_gid }} \
--cap-drop=ALL \
--read-only \
--tmpfs=/var/spool/exim:rw,noexec,nosuid,size=100m \
--network={{ matrix_docker_network }} \
--env-file={{ matrix_mailer_base_path }}/env-mailer \
--hostname={{ hostname_matrix }} \

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@ -12,17 +12,23 @@ Wants={{ service }}
Type=simple
ExecStartPre=-/usr/bin/docker kill matrix-mxisd
ExecStartPre=-/usr/bin/docker rm matrix-mxisd
# mxisd writes an SQLite shared library (libsqlitejdbc.so) to /tmp and executes it from there,
# so /tmp needs to be mounted with an exec option.
ExecStart=/usr/bin/docker run --rm --name matrix-mxisd \
--log-driver=none \
--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
--cap-drop=ALL \
--read-only \
--tmpfs=/tmp:rw,exec,nosuid,size=10m \
--network={{ matrix_docker_network }} \
{% if matrix_mxisd_container_expose_port %}
-p 127.0.0.1:8090:8090 \
{% endif %}
-v {{ matrix_mxisd_config_path }}:/etc/mxisd:ro \
-v {{ matrix_mxisd_data_path }}:/var/mxisd \
-v {{ matrix_mxisd_data_path }}:/var/mxisd:rw \
{{ matrix_mxisd_docker_image }}
ExecStop=-/usr/bin/docker kill matrix-mxisd
ExecStop=-/usr/bin/docker rm matrix-mxisd
Restart=always

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@ -44,7 +44,10 @@ matrix_nginx_proxy_proxy_matrix_identity_api_addr_sans_container: "localhost:809
matrix_nginx_proxy_proxy_matrix_client_api_addr_with_container: "matrix-synapse:8008"
matrix_nginx_proxy_proxy_matrix_client_api_addr_sans_container: "localhost:8008"
# This needs to be equal or higher than the maximum upload size accepted by Synapse.
matrix_nginx_proxy_proxy_matrix_client_api_client_max_body_size: "25M"
matrix_nginx_proxy_proxy_matrix_client_api_client_max_body_size_mb: 25
# The tmpfs at /tmp needs to be large enough to handle multiple concurrent file uploads.
matrix_nginx_proxy_tmp_directory_size_mb: "{{ matrix_nginx_proxy_proxy_matrix_client_api_client_max_body_size_mb * 50 }}"
# A list of strings containing additional configuration blocks to add to the matrix domain's server configuration.
matrix_nginx_proxy_proxy_matrix_additional_server_configuration_blocks: []
@ -85,4 +88,4 @@ matrix_ssl_lets_encrypt_support_email: "{{ host_specific_matrix_ssl_lets_encrypt
matrix_ssl_base_path: "{{ matrix_base_data_path }}/ssl"
matrix_ssl_config_dir_path: "{{ matrix_ssl_base_path }}/config"
matrix_ssl_log_dir_path: "{{ matrix_ssl_base_path }}/log"
matrix_ssl_log_dir_path: "{{ matrix_ssl_base_path }}/log"

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@ -116,7 +116,7 @@ server {
proxy_set_header X-Forwarded-For $remote_addr;
client_body_buffer_size 25M;
client_max_body_size {{ matrix_nginx_proxy_proxy_matrix_client_api_client_max_body_size }};
client_max_body_size {{ matrix_nginx_proxy_proxy_matrix_client_api_client_max_body_size_mb }}M;
proxy_max_temp_file_size 0;
}

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@ -12,10 +12,13 @@ Wants={{ service }}
Type=simple
ExecStartPre=-/usr/bin/docker kill matrix-nginx-proxy
ExecStartPre=-/usr/bin/docker rm matrix-nginx-proxy
ExecStart=/usr/bin/docker run --rm --name matrix-nginx-proxy \
--log-driver=none \
--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
--cap-drop=ALL \
--read-only \
--tmpfs=/tmp:rw,noexec,nosuid,size={{ matrix_nginx_proxy_tmp_directory_size_mb }}m \
--network={{ matrix_docker_network }} \
-p 80:8080 \
-p 443:8443 \
@ -24,6 +27,7 @@ ExecStart=/usr/bin/docker run --rm --name matrix-nginx-proxy \
-v {{ matrix_ssl_config_dir_path }}:{{ matrix_ssl_config_dir_path }}:ro \
-v {{ matrix_static_files_base_path }}:{{ matrix_static_files_base_path }}:ro \
{{ matrix_nginx_proxy_docker_image }}
ExecStop=-/usr/bin/docker kill matrix-nginx-proxy
ExecStop=-/usr/bin/docker rm matrix-nginx-proxy
ExecReload=/usr/bin/docker exec matrix-nginx-proxy /usr/sbin/nginx -s reload

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@ -73,7 +73,7 @@
- name: Note about Postgres importing alternative
debug:
msg: >
msg: >-
Importing Postgres database using the following command: `{{ matrix_postgres_import_command }}`.
If this crashes, you can stop Postgres (`systemctl stop matrix-postgres`),
delete its existing data (`rm -rf {{ matrix_postgres_data_path }}/*`), start it again (`systemctl start matrix-postgres`)

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@ -11,9 +11,12 @@ ExecStart=/usr/bin/docker run --rm --name matrix-postgres \
--log-driver=none \
--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
--cap-drop=ALL \
--read-only \
--tmpfs=/tmp:rw,noexec,nosuid,size=100m \
--tmpfs=/run/postgresql:rw,noexec,nosuid,size=100m \
--network={{ matrix_docker_network }} \
--env-file={{ matrix_postgres_base_path }}/env-postgres-server \
-v {{ matrix_postgres_data_path }}:/var/lib/postgresql/data \
-v {{ matrix_postgres_data_path }}:/var/lib/postgresql/data:rw \
-v /etc/passwd:/etc/passwd:ro \
{{ matrix_postgres_docker_image_to_use }}
ExecStop=-/usr/bin/docker stop matrix-postgres

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@ -13,6 +13,8 @@ ExecStart=/usr/bin/docker run --rm --name matrix-riot-web \
--log-driver=none \
--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
--cap-drop=ALL \
--read-only \
--tmpfs=/tmp:rw,noexec,nosuid,size=10m \
-v {{ matrix_riot_web_data_path }}/nginx.conf:/etc/nginx/nginx.conf:ro \
-v /dev/null:/etc/nginx/conf.d/default.conf:ro \
-v {{ matrix_riot_web_data_path }}/config.json:/etc/riot-web/config.json:ro \

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@ -39,6 +39,9 @@ matrix_synapse_max_upload_size_mb: 10
matrix_synapse_max_log_file_size_mb: 100
matrix_synapse_max_log_files_count: 10
# The tmpfs at /tmp needs to be large enough to handle multiple concurrent file uploads.
matrix_synapse_tmp_directory_size_mb: "{{ matrix_synapse_max_upload_size_mb * 50 }}"
# Log levels
# Possible options are defined here https://docs.python.org/3/library/logging.html#logging-levels
# warning: setting log level to DEBUG will make synapse log sensitive information such
@ -187,4 +190,4 @@ matrix_mautrix_whatsapp_enabled: false
matrix_mautrix_whatsapp_docker_image: "tulir/mautrix-whatsapp:latest"
matrix_mautrix_whatsapp_base_path: "{{ matrix_base_data_path }}/mautrix-whatsapp"
matrix_mautrix_whatsapp_base_path: "{{ matrix_base_data_path }}/mautrix-whatsapp"

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@ -18,11 +18,14 @@ ExecStartPre=-/usr/bin/docker rm matrix-synapse
# we'd write files to the local filesystem and fusermount will complain.
ExecStartPre=/bin/sleep 5
{% endif %}
ExecStart=/usr/bin/docker run --rm --name matrix-synapse \
--log-driver=none \
--user={{ matrix_user_uid }}:{{ matrix_user_gid }} \
--cap-drop=ALL \
--entrypoint=python \
--read-only \
--tmpfs=/tmp:rw,noexec,nosuid,size={{ matrix_synapse_tmp_directory_size_mb }}m \
--network={{ matrix_docker_network }} \
-e SYNAPSE_CACHE_FACTOR={{ matrix_synapse_cache_factor }} \
{% if matrix_synapse_federation_enabled %}
@ -31,14 +34,15 @@ ExecStart=/usr/bin/docker run --rm --name matrix-synapse \
{% if matrix_synapse_container_expose_client_server_api_port %}
-p 127.0.0.1:8008:8008 \
{% endif %}
-v {{ matrix_synapse_config_dir_path }}:/data \
-v {{ matrix_synapse_run_path }}:/matrix-run \
-v {{ matrix_synapse_config_dir_path }}:/data:ro \
-v {{ matrix_synapse_run_path }}:/matrix-run:rw \
-v {{ matrix_synapse_base_path }}/storage:/matrix-media-store-parent:slave \
{% for volume in matrix_synapse_container_additional_volumes %}
-v {{ volume.src }}:{{ volume.dst }}:{{ volume.options }} \
{% endfor %}
{{ matrix_synapse_docker_image }} \
-m synapse.app.homeserver -c /data/homeserver.yaml
ExecStop=-/usr/bin/docker kill matrix-synapse
ExecStop=-/usr/bin/docker rm matrix-synapse
Restart=always