You can use Composer with the Bluemix Blockchain service today.
However, you must be running a local copy of the Composer Playground as the version of Composer running on Bluemix (fabric-composer.mybluemix.net) only supports the web connection profile at the moment.
You can set up a local copy of the Composer Playground by following the instructions here: https://fabric-composer.github.io/start/getting-started-playground.html
Here's the connection profile that I used to connect to the Bluemix Blockchain service:
{
"type": "hlf",
"membershipServicesURL": "grpcs://f8946a6180f2431088ca17ce931a49dc-ca.us.blockchain.ibm.com:30001",
"peerURL": "grpcs://f8946a6180f2431088ca17ce931a49dc-vp1.us.blockchain.ibm.com:30001",
"eventHubURL": "grpcs://f8946a6180f2431088ca17ce931a49dc-vp1.us.blockchain.ibm.com:31001",
"keyValStore": "/home/composer/.composer-credentials",
"deployWaitTime": 300,
"invokeWaitTime": 30,
"certificate": "-----BEGIN CERTIFICATE-----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\n-----END CERTIFICATE-----\n-----BEGIN CERTIFICATE-----\nMIIDrDCCApSgAwIBAgIQCssoukZe5TkIdnRw883GEjANBgkqhkiG9w0BAQwFADBh\nMQswCQYDVQQGEwJVUzEVMBMGA1UEChMMRGlnaUNlcnQgSW5jMRkwFwYDVQQLExB3\nd3cuZGlnaWNlcnQuY29tMSAwHgYDVQQDExdEaWdpQ2VydCBHbG9iYWwgUm9vdCBD\nQTAeFw0xMzAzMDgxMjAwMDBaFw0yMzAzMDgxMjAwMDBaMEwxCzAJBgNVBAYTAlVT\nMRUwEwYDVQQKEwxEaWdpQ2VydCBJbmMxJjAkBgNVBAMTHURpZ2lDZXJ0IEVDQyBT\nZWN1cmUgU2VydmVyIENBMHYwEAYHKoZIzj0CAQYFK4EEACIDYgAE4ghC6nfYJN6g\nLGSkE85AnCNyqQIKDjc/ITa4jVMU9tWRlUvzlgKNcR7E2Munn17voOZ/WpIRllNv\n68DLP679Wz9HJOeaBy6Wvqgvu1cYr3GkvXg6HuhbPGtkESvMNCuMo4IBITCCAR0w\nEgYDVR0TAQH/BAgwBgEB/wIBADAOBgNVHQ8BAf8EBAMCAYYwNAYIKwYBBQUHAQEE\nKDAmMCQGCCsGAQUFBzABhhhodHRwOi8vb2NzcC5kaWdpY2VydC5jb20wQgYDVR0f\nBDswOTA3oDWgM4YxaHR0cDovL2NybDMuZGlnaWNlcnQuY29tL0RpZ2lDZXJ0R2xv\nYmFsUm9vdENBLmNybDA9BgNVHSAENjA0MDIGBFUdIAAwKjAoBggrBgEFBQcCARYc\naHR0cHM6Ly93d3cuZGlnaWNlcnQuY29tL0NQUzAdBgNVHQ4EFgQUo53mH/naOU/A\nbuiRy5Wl2jHiCp8wHwYDVR0jBBgwFoAUA95QNVbRTLtm8KPiGxvDl7I90VUwDQYJ\nKoZIhvcNAQEMBQADggEBAMeKoENL7HTJxavVHzA1Nm6YVntIrAVjrnuaVyRXzG/6\n3qttnMe2uuzO58pzZNvfBDcKAEmzP58mrZGMIOgfiA4q+2Y3yDDo0sIkp0VILeoB\nUEoxlBPfjV/aKrtJPGHzecicZpIalir0ezZYoyxBEHQa0+1IttK7igZFcTMQMHp6\nmCHdJLnsnLWSB62DxsRq+HfmNb4TDydkskO/g+l3VtsIh5RHFPVfKK+jaEyDj2D3\nloB5hWp2Jp2VDCADjT7ueihlZGak2YPqmXTNbk19HOuNssWvFhtOyPNV6og4ETQd\nEa8/B6hPatJ0ES8q/HO3X8IVQwVs1n3aAr0im0/T+Xc=\n-----END CERTIFICATE-----\n-----BEGIN CERTIFICATE-----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\nCAUw7C29C79Fv1C5qfPrmAESrciIxpg0X40KPMbp1ZWVbd4=\n-----END CERTIFICATE-----\n",
"certificatePath": "/certs/peer/cert.pem"
}
The hostname and port numbers in the URLs must come from the Bluemix dashboard. I find it easiest to get this information by navigating to "Service Credentials" and viewing the default credentials "Credentials-1". Here's an explanation of where each URL comes from:
membershipServicesURL is always "grpcs://" + url from the "ca" object (url also being discovery_host + ":" + discovery_port).
peerURL is always "grpcs://" + discovery_host + ":" + discovery_port from one of the peers listed in the "peers" array.
eventHubURL is always "grpcs://" + event_host + ":" + event_port from one of the peers listed in the "peers" array.
keyValStore is a directory on the file system of the system running Composer. If using the Docker images, then use the "/home/composer/.composer-credentials" path, otherwise use a directory that exists on your machine.
certificate comes from the "us.blockchain.ibm.com.cert" file which can be downloaded from the "cert" property in the credentials, for example "https://blockchain-certs.mybluemix.net/us.blockchain.ibm.com.cert". If you create this JSON manually, you must ensure that it ends with a "\n" newline character.
certificatePath comes from the "cert_path" property in the credentials.
You can also get the enrolment ID and enrolment secret to use for Bluemix from the credentials page; I recommend using "admin". Note that if you use the REST APIs to interact with the Bluemix service then you cannot use those same credentials with Composer.
One thing to note however is that the Bluemix Blockchain service can be unreliable due to problems with the event hub connection being timed out due to inactivity. When this happens, Composer will terminate and you may see an error. We are awaiting a fix to the hfc (Hyperledger Fabric Client) Node.js module that will correctly handle this error and reconnect as required.
