This implements a special "RESET" value that can be used to reset the
list of capabilities to add/drop when updating a service.
Given the following service;
| CapDrop | CapAdd |
| -------------- | ------------- |
| CAP_SOME_CAP | |
When updating the service, and applying `--cap-drop RESET`, the "drop" list
is reset to its default:
| CapDrop | CapAdd |
| -------------- | ------------- |
| | |
When updating the service, and applying `--cap-drop RESET`, combined with
`--cap-add CAP_SOME_CAP` and `--cap-drop CAP_SOME_OTHER_CAP`:
| CapDrop | CapAdd |
| -------------- | ------------- |
| CAP_FOO_CAP | CAP_SOME_CAP |
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Adding/removing capabilities when updating a service is considered a tri-state;
- if the capability was previously "dropped", then remove it from "CapabilityDrop",
but do NOT add it to "CapabilityAdd". However, if the capability was not yet in
the service's "CapabilityDrop", then simply add it to the service's "CapabilityAdd"
- likewise, if the capability was previously "added", then remove it from
"CapabilityAdd", but do NOT add it to "CapabilityDrop". If the capability was
not yet in the service's "CapabilityAdd", then simply add it to the service's
"CapabilityDrop".
In other words, given a service with the following:
| CapDrop | CapAdd |
| -------------- | ------------- |
| CAP_SOME_CAP | |
When updating the service, and applying `--cap-add CAP_SOME_CAP`, the previously
dropped capability is removed:
| CapDrop | CapAdd |
| -------------- | ------------- |
| | |
When updating the service a second time, applying `--cap-add CAP_SOME_CAP`,
capability is now added:
| CapDrop | CapAdd |
| -------------- | ------------- |
| | CAP_SOME_CAP |
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
When creating and updating services, we need to avoid unneeded service churn.
The interaction of separate lists to "add" and "drop" capabilities, a special
("ALL") capability, as well as a "relaxed" format for accepted capabilities
(case-insensitive, `CAP_` prefix optional) make this rather involved.
This patch updates how we handle `--cap-add` / `--cap-drop` when _creating_ as
well as _updating_, with the following rules/assumptions applied:
- both existing (service spec) and new (values passed through flags or in
the compose-file) are normalized and de-duplicated before use.
- the special "ALL" capability is equivalent to "all capabilities" and taken
into account when normalizing capabilities. Combining "ALL" capabilities
and other capabilities is therefore equivalent to just specifying "ALL".
- adding capabilities takes precedence over dropping, which means that if
a capability is both set to be "dropped" and to be "added", it is removed
from the list to "drop".
- the final lists should be sorted and normalized to reduce service churn
- no validation of capabilities is handled by the client. Validation is
delegated to the daemon/server.
When deploying a service using a docker-compose file, the docker-compose file
is *mostly* handled as being "declarative". However, many of the issues outlined
above also apply to compose-files, so similar handling is applied to compose
files as well to prevent service churn.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
The shorthand `-v` will auto-create the host-path as a directory if
the socket is not yet up, instead of failing the container. To prevent
accidental creation of `/var/run/docker.sock` as a directory, use
the `--mount` flag instead, which does not auto-create host-paths.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Bash is installed already, so we might as well use it as a default.
This also removes the DOCKER_CLI_SHELL variable, which was added
in b039db985a to allow using bash
instead of (a)sh. Now that Bash is the default, there should be
no need to override, and we can keep things simple.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Building form source is slower, but will support other architectures, such as arm64
Before:
=> [gotestsum 1/2] ADD https://github.com/gotestyourself/gotestsum/releases/download/v0.4.0/gotestsum_0.4.0_linux_amd64.tar.gz gotestsum.tar.gz 2.3s
=> [gotestsum 2/2] RUN tar -xf gotestsum.tar.gz gotestsum -C /go/bin 1.8s
After:
=> [gotestsum 1/1] RUN go get gotest.tools/gotestsum@v0.4.0 13.0s
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Sebastiaan van Stijn
Silvin Lubecki
Jennings Zhang
Harald Albers
Tibor Vass
Sebastiaan van Stijn
Albin Kerouanton
Brian Goff
Olli Janatuinen
Des Preston