DockerCLI/docs/reference/commandline/trust_signer_add.md

# trust signer add

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Add a signer

### Options

| Name    | Type   | Default | Description                          |
|:--------|:-------|:--------|:-------------------------------------|
| `--key` | `list` |         | Path to the signer's public key file |


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## Description

`docker trust signer add` adds signers to signed repositories.

## Examples

### Add a signer to a repository

To add a new signer, `alice`, to this repository:

```console
$ docker trust inspect --pretty example/trust-demo

No signatures for example/trust-demo


List of signers and their keys:

SIGNER              KEYS
bob                 5600f5ab76a2

Administrative keys for example/trust-demo:
Repository Key: 642692c14c9fc399da523a5f4e24fe306a0a6ee1cc79a10e4555b3c6ab02f71e
Root Key:       3cb2228f6561e58f46dbc4cda4fcaff9d5ef22e865a94636f82450d1d2234949
```

Add `alice` with `docker trust signer add`:

```console
$ docker trust signer add alice example/trust-demo --key alice.crt
  Adding signer "alice" to example/trust-demo...
  Enter passphrase for repository key with ID 642692c:
Successfully added signer: alice to example/trust-demo
```

`docker trust inspect --pretty` now lists `alice` as a valid signer:

```console
$ docker trust inspect --pretty example/trust-demo

No signatures for example/trust-demo


List of signers and their keys:

SIGNER              KEYS
alice               05e87edcaecb
bob                 5600f5ab76a2

Administrative keys for example/trust-demo:
Repository Key: 642692c14c9fc399da523a5f4e24fe306a0a6ee1cc79a10e4555b3c6ab02f71e
Root Key:       3cb2228f6561e58f46dbc4cda4fcaff9d5ef22e865a94636f82450d1d2234949
```

## Initialize a new repository and add a signer

When adding a signer on a repository for the first time, `docker trust signer add` sets up a new repository if it doesn't exist.

```console
$ docker trust inspect --pretty example/trust-demo

no signatures or cannot access example/trust-demo
```

```console
$ docker trust signer add alice example/trust-demo --key alice.crt

Initializing signed repository for example/trust-demo...
Enter passphrase for root key with ID 748121c:
Enter passphrase for new repository key with ID 95b9e55:
Repeat passphrase for new repository key with ID 95b9e55:
Successfully initialized "example/trust-demo"

Adding signer "alice" to example/trust-demo...
Successfully added signer: alice to example/trust-demo
```

```console
$ docker trust inspect --pretty example/trust-demo

No signatures for example/trust-demo


SIGNED TAG          DIGEST                                                             SIGNERS

List of signers and their keys:

SIGNER              KEYS
alice               6d52b29d940f

Administrative keys for example/trust-demo:
Repository Key: 95b9e5565eac3ef5ec01406801bdfb70feb40c17808d2222427c18046eb63beb
Root Key:       748121c14bd1461f6c58cb3ef39087c8fdc7633bb11a98af844fd9a04e208103
```

## Add a signer to multiple repositories

To add a signer, `alice`, to multiple repositories:

```console
$ docker trust inspect --pretty example/trust-demo

SIGNED TAG          DIGEST                                                             SIGNERS
v1                  74d4bfa917d55d53c7df3d2ab20a8d926874d61c3da5ef6de15dd2654fc467c4   bob

List of signers and their keys:

SIGNER              KEYS
bob                 5600f5ab76a2

Administrative keys for example/trust-demo:
Repository Key: ecc457614c9fc399da523a5f4e24fe306a0a6ee1cc79a10e4555b3c6ab02f71e
Root Key:       3cb2228f6561e58f46dbc4cda4fcaff9d5ef22e865a94636f82450d1d2234949
```

```console
$ docker trust inspect --pretty example/trust-demo2

SIGNED TAG          DIGEST                                                             SIGNERS
v1                  74d4bfa917d55d53c7df3d2ab20a8d926874d61c3da5ef6de15dd2654fc467c4   bob

List of signers and their keys:

SIGNER              KEYS
bob                 5600f5ab76a2

Administrative keys for example/trust-demo2:
Repository Key: ece554f14c9fc399da523a5f4e24fe306a0a6ee1cc79a10e4553d2ab20a8d9268
Root Key:       3cb2228f6561e58f46dbc4cda4fcaff9d5ef22e865a94636f82450d1d2234949
```

Add `alice` to both repositories with a single `docker trust signer add` command:

```console
$ docker trust signer add alice example/trust-demo example/trust-demo2 --key alice.crt

Adding signer "alice" to example/trust-demo...
Enter passphrase for repository key with ID 95b9e55:
Successfully added signer: alice to example/trust-demo

Adding signer "alice" to example/trust-demo2...
Enter passphrase for repository key with ID ece554f:
Successfully added signer: alice to example/trust-demo2
```

`docker trust inspect --pretty` now lists `alice` as a valid signer of both `example/trust-demo` and `example/trust-demo2`:


```console
$ docker trust inspect --pretty example/trust-demo

SIGNED TAG          DIGEST                                                             SIGNERS
v1                  74d4bfa917d55d53c7df3d2ab20a8d926874d61c3da5ef6de15dd2654fc467c4   bob

List of signers and their keys:

SIGNER              KEYS
alice               05e87edcaecb
bob                 5600f5ab76a2

Administrative keys for example/trust-demo:
Repository Key: 95b9e5514c9fc399da523a5f4e24fe306a0a6ee1cc79a10e4555b3c6ab02f71e
Root Key:       3cb2228f6561e58f46dbc4cda4fcaff9d5ef22e865a94636f82450d1d2234949
```

```console
$ docker trust inspect --pretty example/trust-demo2

SIGNED TAG          DIGEST                                                             SIGNERS
v1                  74d4bfa917d55d53c7df3d2ab20a8d926874d61c3da5ef6de15dd2654fc467c4   bob

List of signers and their keys:

SIGNER              KEYS
alice               05e87edcaecb
bob                 5600f5ab76a2

Administrative keys for example/trust-demo2:
Repository Key: ece554f14c9fc399da523a5f4e24fe306a0a6ee1cc79a10e4553d2ab20a8d9268
Root Key:       3cb2228f6561e58f46dbc4cda4fcaff9d5ef22e865a94636f82450d1d2234949
```

`docker trust signer add` adds signers to repositories on a best effort basis.
It continues to add the signer to subsequent repositories if one attempt fails:

```console
$ docker trust signer add alice example/unauthorized example/authorized --key alice.crt

Adding signer "alice" to example/unauthorized...
you are not authorized to perform this operation: server returned 401.

Adding signer "alice" to example/authorized...
Enter passphrase for repository key with ID c6772a0:
Successfully added signer: alice to example/authorized

failed to add signer to: example/unauthorized
```