Chamber is a tool for managing secrets. Currently it does so by storing secrets in SSM Parameter Store, an AWS service for storing secrets.
For detailed info about using chamber, please read The Right Way To Manage Secrets
- Use of the SSM Parameter Store's path-based API is now required. Support
added in v2.0 to avoid it has been removed. The
CHAMBER_NO_PATHSenvironment variable no longer has any effect. You must migrate to the new storage format using the instructions below, using a 2.x version of chamber. - The
--min-throttle-delayoption no longer has any effect. Support for specifying a minimum throttle delay has been removed from the underlying AWS SDK with no direct replacement. Instead, set the new--retry-modeoption to "adaptive" to use an experimental model that accounts for throttling errors. - Context arguments are required for
Storemethods. This is a consequence of migrating to a new AWS SDK. This change has no effect for CLI users, but those using chamber as a library must update their code to pass contexts. - The deprecated
NewS3Storeconstructor has been removed. UseNewS3StoreWithBucketinstead.
Starting with version 2.0, chamber uses parameter store's path based API by default.
Chamber pre-2.0 supported this API using the CHAMBER_USE_PATHS environment variable.
The paths based API has performance benefits and is the recommended best practice
by AWS.
As a side effect of this change, if you didn't use path based secrets before 2.0,
you will need to set CHAMBER_NO_PATHS to enable the old behavior. This option
is deprecated, and We recommend only using this setting for supporting existing
applications.
To migrate to the new format, you can take advantage of the export and import
commands. For example, if you wanted to convert secrets for service foo to the
new format using chamber 2.0, you can do:
CHAMBER_NO_PATHS=1 chamber export foo | chamber import foo -Support for very old versions of Go has been dropped, and chamber will only test against versions of Go covered by the Go Release Policy, e.g. the two most recent major versions. This will ensure that we can reliably update dependencies as needed. Additionally, chamber binaries will be built with the latest stable version of Go at the time of release.
If you have a functional go environment, you can install with:
go install github.com/segmentio/chamber/v3@latestNote that installing with go install will not produce an executable containing
any versioning information. This information is passed at compilation time when
the Makefile is used for compilation. Without this information, chamber version
outputs the following:
$ chamber version
chamber dev
Using chamber requires you to be running in an environment with an
authenticated AWS user which has the appropriate permission to read/write
values to SSM Parameter Store.
This is going to vary based on your organization but chamber needs AWS credentials to run.
One of the easiest ways to do so is by using aws-vault. To adjust these instructions for your needs, examine the env output of Aws-Vault: How It Works and use your organization's secrets tool accordingly with chamber.
aws-vault exec prod -- chamberFor this reason, it is recommended that you create an alias in your shell of
choice to save yourself some typing, for example (from my .zshrc):
alias chamberprod='aws-vault exec production -- chamber'Chamber expects to find a KMS key with alias parameter_store_key in the
account that you are writing/reading secrets. You can follow the AWS KMS
documentation
to create your key, and follow this guide to set up your
alias.
If you are a Terraform user, you can create your key with the following:
resource "aws_kms_key" "parameter_store" {
description = "Parameter store kms master key"
deletion_window_in_days = 10
enable_key_rotation = true
}
resource "aws_kms_alias" "parameter_store_alias" {
name = "alias/parameter_store_key"
target_key_id = "${aws_kms_key.parameter_store.id}"
}If you'd like to use an alternate KMS key to encrypt your secrets, you can set
the environment variable CHAMBER_KMS_KEY_ALIAS. As an example, the following
will use your account's default SSM alias:
CHAMBER_KMS_KEY_ALIAS=aws/ssm
$ chamber write <service> <key> <value|->This operation will write a secret into the secret store. If a secret with that key already exists, it will increment the version and store a new value.
If - is provided as the value argument, the value will be read from standard
input.
Secret keys are normalized automatically. The - will be _ and the letters will
be converted to upper case (for example a secret with key secret_key and
secret-key will become SECRET_KEY).
Starting with version 3.0, the service name "_chamber" is reserved for chamber's internal use. You will be warned when using the service for any chamber operation.
$ chamber write <service> <key> <value> --tags key1=value1,key2=value2This operation will write a secret into the secret store with the specified tags. Tagging on write is only available for new secrets.
$ chamber tag write <service> <key> tag1=value1 tag2=value2
Key Value
tag1 value1
tag2 value2
$ chamber tag read <service> <key>
Key Value
tag1 value1
tag2 value2
$ chamber tag delete <service> <key> tag1
$ chamber tag read <service> <key>
Key Value
tag2 value2Writing tags normally leaves other tags intact. If you want to replace all tags
with the new ones, use --delete-other-tags flag. Note: The option may change
before the next major release.
$ chamber tag write --delete-other-tags <service> <key> tag1=value1
Key Value
tag1 value1$ chamber list service
Key Version LastModified User
apikey 2 06-09 17:30:56 daniel-fuentes
other 1 06-09 17:30:34 daniel-fuentesListing secrets should show the key names for a given service, along with other useful metadata including when the secret was last modified, who modified it, and what the current version is.
$ chamber list -e service
Key Version LastModified User Value
apikey 2 06-09 17:30:56 daniel-fuentes apikeyvalue
other 1 06-09 17:30:34 daniel-fuentes othervalueListing secrets with expand parameter should show the key names and values for a given service, along with other useful metadata including when the secret was last modified, who modified it, and what the current version is.
$ chamber history service key
Event Version Date User
Created 1 06-09 17:30:19 daniel-fuentes
Updated 2 06-09 17:30:56 daniel-fuentesThe history command gives a historical view of a given secret. This view is
useful for auditing changes, and can point you toward the user who made the
change so it's easier to find out why changes were made.
$ chamber exec <service...> -- <your executable>exec populates the environment with the secrets from the specified services
and executes the given command. Secret keys are converted to upper case (for
example a secret with key secret_key will become SECRET_KEY).
Secrets from services are loaded in the order specified in the command. For
example, if you do chamber exec app apptwo -- ... and both apps have a secret
named api_key, the api_key from apptwo will be the one set in your
environment.
$ chamber read service key
Key Value Version LastModified User
key secret 1 06-09 17:30:56 daniel-fuentesread provides the ability to print out the value of a single secret, as well
as the secret's additional metadata. It does not provide the ability to print
out multiple secrets in order to discourage accessing extra secret material
that is unneeded. Parameter store automatically versions secrets and passing
the --version/-v flag to read can print older versions of the secret. Default
version (-1) is the latest secret.
$ chamber export [--format <format>] [--output-file <file>] <service...>
{"key":"secret"}export provides ability to export secrets in various file formats. The following
file formats are supported:
- json (default)
- yaml
- java-properties
- csv
- tsv
- dotenv
- tfvars
File is written to standard output by default but you may specify an output file.
chamber can emit environment variables in both dotenv format and exported shell
environment variables. As chamber allows creating key names that are themselves
not valid shell variable names, secrets emitted in this format will have their
keys modified to confirm to POSIX shell environment variable naming rules:
- variable names must begin with a letter or an underscore
- variable names must not begin with a number
- variable names must only contain letters, numbers, or underscores
As there is no formal dotenv spec, chamber attempts to
adhere to compliance with joho/godotenv (which
is itself a port of the Ruby library
bkeepers/dotenv). The output should be generally
cross-compatible with alternative parsers, but without a formal spec compatibility
is not guaranteed.
Of note:
- all key names will be sanitized according the the POSIX shell rules above, and cast to uppercase
- all values will be rendered using special characters instead of string literals,
e.g. newlines replaced with the character
\n, tabstops replaced with the character\t, etc.- no whitespace trimming will be performed on any values
Alternatively, chamber may be used to set local environment variables directly
with the chamber env command. For example,
source <(chamber env service)`
printf "%s" "$SERVICE_VAR"Note that all secrets printed this way will be prefixed with export, so if sourced
inline as in the above example, then any and all secrets will then be available
to any process run after sourcing.
the env subcommand supports output formatting in two specific ways:
chamber env -h
Print the secrets from the parameter store in a format to export as environment variables
Usage:
chamber env <service> [flags]
Flags:
-p, --preserve-case preserve variable name case
-e, --escape-strings escape special characters in values
As chamber allows creation of keys with mixed case, --preserve-case will ensure
that the original key case is preserved. Note that this will not prevent the
key name from being sanitized according to the above POSIX shell rules.
By default, values will be rendered using string literals, e.g. newlines will
be printed as literal newlines, tabstops as literal tabstops. Output may be
emitted using escaped special characters instead (identical to
chamber export -o dotenv)) by using the flag --escape-strings.
$ chamber import [--normalize-keys] <service> <filepath>import provides the ability to import secrets from a json or yaml file (like
the kind you get from chamber export).
Note By default,
importwill not normalize key inputs, meaning that keys will be written to the secrets backend in the format they exist in the source file. In order to normalize keys on import, provide the--normalize-keysflag
When normalizing keys, before write, the key will be be first converted to lowercase
to match how chamber write handles keys.
Example: DB_HOST will be converted to db_host.
You can set filepath to - to instead read input from stdin.
$ chamber delete [--exact-key] service keydelete provides the ability to remove a secret from chamber permanently,
including the secret's additional metadata. There is no way to recover a
secret once it has been deleted so care should be taken with this command.
Note By default,
deletewill normalize any provided keys. To change that behavior, provide the--exact-keyflag to attempt to delete the raw provided key.
Example: Given the following setup,
$ chamber list service
Key Version LastModified User
apikey 2 06-09 17:30:56 daniel-fuentes
APIKEY 1 06-09 17:30:34 daniel-fuentesCalling
$ chamber delete --exact-key service APIKEYwill delete only APIKEY from the service and leave only
$ chamber list service
Key Version LastModified User
apikey 2 06-09 17:30:56 daniel-fuentes$ chamber find keyfind provides the ability to locate which services use the same key names.
$ chamber find value --by-valuePassing --by-value or -v will search the values of all secrets and return
the services and keys which match.
$ chamber list-services [<prefix>]list-services lists the available services. You can provide a prefix to limit
the results.
Chamber uses AWS SDK for Go. To use a
region other than what is specified in $HOME/.aws/config, set the environment
variable "AWS_REGION".
$ AWS_REGION=us-west-2 chamber list service
Key Version LastModified User
apikey 3 07-10 09:30:41 daniel-fuentes
other 1 07-10 09:30:35 daniel-fuentesChamber does not currently read the value of "AWS_DEFAULT_REGION". See https://github.com/aws/aws-sdk-go#configuring-aws-region for more details.
If you'd like to use a different region for chamber without changing AWS_REGION,
you can use CHAMBER_AWS_REGION to override just for chamber.
If you'd like to use a custom SSM endpoint for chamber, you can use CHAMBER_AWS_SSM_ENDPOINT
to override the default URL.
Chamber supports AWS Secrets Manager as an optional backend. For example:
chamber -b secretsmanager write myservice foo fah
chamber -b secretsmanager write myservice foo2 fah2
If you'd like to use a custom Secrets Manager endpoint for chamber, you can use
CHAMBER_AWS_SECRETS_MANAGER_ENDPOINT to override the default URL.
Warning
Prior to v3.0.0, the endpoint could also be overridden with CHAMBER_AWS_SSM_ENDPOINT. This
has been deprecated and will stop working in a future chamber release. Please use
CHAMBER_AWS_SECRETS_MANAGER_ENDPOINT instead.
By default, chamber store secrets in AWS Parameter Store. We now also provide an experimental S3 backend for storing secrets in S3 instead.
To configure chamber to use the S3 backend, use chamber -b s3 --backend-s3-bucket=mybucket.
Preferably, this bucket should reject uploads that do not set the server side
encryption header (see this doc for details how)
This feature is experimental, and not currently meant for production work.
This backend is similar to the S3 Backend but uses KMS Key Encryption to encrypt your documents at rest, similar to the SSM Backend which encrypts your secrets at rest. You can read how S3 Encrypts documents with KMS here.
The highlights of SSE-KMS are:
- You can choose to create and manage encryption keys yourself, or you can choose to use your default service key uniquely generated on a customer by service by region level.
- The ETag in the response is not the MD5 of the object data.
- The data keys used to encrypt your data are also encrypted and stored alongside the data they protect.
- Auditable master keys can be created, rotated, and disabled from the AWS KMS console.
- The security controls in AWS KMS can help you meet encryption-related compliance requirements.
Source: Protecting data using server-side encryption with AWS Key Management Service keys (SSE-KMS)
To configure chamber to use the S3 KMS backend, use
chamber -b s3-kms --backend-s3-bucket=mybucket --kms-key-alias=alias/keyname.
You must also supply an environment variable of the KMS Key Alias to use
CHAMBER_KMS_KEY_ALIAS, by default "alias/parameter_store_key"
will be used.
Preferably, this bucket should reject uploads that do not set the server side encryption header (see this doc for details how)
When changing secrets between KMS Keys, you must first delete the Chamber secret with the existing KMS Key, then write it again with new KMS Key.
If services contain multiple KMS Keys, chamber list and chamber exec will only
show Chamber secrets encrypted with KMS Keys you have access to.
This feature is experimental, and not currently meant for production work.
If it's preferred to not use any backend at all, use chamber -b null. Doing so
will forward existing ENV variables as if Chamber is not in between.
This feature is experimental, and not currently meant for production work.
chamber includes some usage analytics code which Segment uses internally for
tracking usage of internal tools. This analytics code is turned off by default,
and can only be enabled via a linker flag at build time, which we do not set for
public github releases.
To cut a new release, just push a tag named v<semver> where <semver> is a
valid semver version. This tag will be used by Github Actions to automatically publish
a github release.
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